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  • 1990-1994  (116)
  • 1965-1969  (19)
  • 1950-1954
  • 1890-1899
  • 1800-1809
  • Catecholamines
  • 1
    Electronic Resource
    Electronic Resource
    The effect of a taurine-containing drink on performance in 10 endurance-athletes (1994)
    Springer
    Amino acids 7 (1994), S. 45-56 
    Details
    ISSN: 1438-2199
    Keywords: Amino acids ; Taurine ; Heart rate ; Catecholamines ; Performance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To determine the effect of a taurine-enriched drink “Red Bull” on performance, 10 endurance-athletes performed three trials. After 60 min. cycling at approximately 70% VO2 max, the subjects pedalled to exhaustion on a cycle ergometer. During each exercise, the subjects received 500 ml of a test-drink after 30 min. submaximal cycling: “Red Bull” without taurine, without glucuronolacton (U1), “Red Bull” without taurine, without glucuronolacton, without caffeine (U2) and “Red Bull” original drink containing taurine, glucuronolacton and caffeine (U3). The heart rate level was significantly lower in U3 (p = 0,0031) 15 min. after application. The plasma catecholamines increased slightly from begin of exercise to 15 min. after application of the drinks in all trials but remained on a significantly lower level in U3 (epinephrine (p = 0,0011) and norepinephrine (p = 0,0003). Endurance time was significantly longer with “Red Bull” original in U3 (p = 0,015). The results of this study show a positive effect of a taurine-containing drink on hormonal responses which leads to a higher performance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00808445
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  • 2
    Electronic Resource
    Electronic Resource
    Hypokalemia in opiate overdose (1994)
    Springer
    Journal of molecular medicine 72 (1994), S. 471-471 
    Details
    ISSN: 1432-1440
    Keywords: Opiate overdose ; Heroin ; Cocaine ; Potassium ; Hypokalemia ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00180525
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  • 3
    Electronic Resource
    Electronic Resource
    Decrease of extracellular catecholamine content in the vicinity of cortical penicillin-induced epileptogenic focus: voltammetric study in the rat (1994)
    Springer
    Experimental brain research 98 (1994), S. 97-100 
    Details
    ISSN: 1432-1106
    Keywords: Epileptogenic cortical focus ; Catecholamines ; Voltammetry ; Penicillin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Differential pulse voltammetry with carbonfibre microelectrodes was used in chloralhydrate-anaesthetized rats to test the influence of the penicillin-G-Na (PNC)-induced (topical application, approximately 2000 IU) epileptic activity on the catecholamine content (catechol-oxidative current, CA.OC) in the parietal cortex. In the experimental group (n = 4) after PNC a nonlinear CA.OC lowering was observed; this decrease during the first 10 min was faster than in the control group (n = 4). Significantly different values were observed from the 4th min after application. The best fit for this experimental curve gave the logarithmic function (f(t) = a + b.ln(t), a =105.8, b= -10.6) with regression coefficient r = 0.98. From the 12th min after PNC application until the end of the experiments (54th min) CA.OC values ranged from 78% to 84% of the control group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229113
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  • 4
    Electronic Resource
    Electronic Resource
    Variation in tolerance to the antinociceptive, hormonal and thermal effects of morphine after a 5-day pre-treatment of male rats with increasing doses of morphine (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 349 (1994), S. 161-169 
    Details
    ISSN: 1432-1912
    Keywords: Tolerance ; Morphine ; TSH ; Prolactin ; Catecholamines ; Hypothalamus ; Temperature ; Antinociception
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The manifestation of tolerance to the effects of morphine on nociception and the secretion of anterior pituitary hormones, and the correlation of hormonal effects to changes in body temperature and to hypothalamic monoamines were studied in male rats. Morphine (three times a day in increasing doses) or saline (control) were administered intraperitoneally during a 5-day treatment and either saline or morphine was administered as an acute challenge 92 h later. The influence of the thermal environment on the effect of morphine on the body temperature was also studied. The 5-day morphine regimen was sufficient for the development of tolerance to the antinociceptive effect of morphine. After a 92-h lag-time, the tolerance was still complete. Tolerance to the depressant effect of morphine (10–25 mg/kg) on cold-stimulated TSH secretion was seen at 2 h, but was only barely detectable at 1 h, after the injection of a challenge dose. On the other hand, a tolerance to the stimulatory effect of morphine on prolactin secretion was already seen 1 h after the acute dose of morphine. Tolerance to the hypothermic effect of morphine (25 mg/kg) was evident in rats kept at +4°C after the challenge dose. On the contrary, no tolerance to the hyperthermic effect of morphine (15 or 25 mg/kg) was observed in rats kept at +30°C. However, the hyperthermia was reversed when these rats were moved to +4°C for 30 min, irrespective of whether they were morphine pretreated or not. Thus the removal of the hyperthermic stimulus decreased the core temperature of all rats. We conclude, that with a 5-day morphine regimen and a 4-day lag time, tolerance developed to the antinociceptive, hypothermic and some hormonal effects of mor phine but not to its hyperthermic effect or to its effects on hypothalamic 5-HIAA concentrations. Neither the changes in the rectal temperature nor the minor alterations in the concentrations of the hypothalamic amine neurotransmitters correlated with the manifestation of tolerance to the cold-stimulated TSH secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169832
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  • 5
    Electronic Resource
    Electronic Resource
    The role of activation of the sympathetic nervous system in the central pressor action of calcitonin gene-related peptide in conscious rats (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 349 (1994), S. 394-400 
    Details
    ISSN: 1432-1912
    Keywords: Calcitonin gene-related peptide ; CGRP(8–37) ; Intracerebroventricular administration ; Catecholamines ; Sympathetic nervous system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of intracerebroventricular (i.cv.) administration of calcitonin gene-related (CGRP) on blood pressure and heart rate (HR), and the underlying mechanisms were studied in conscious rats. CGRP (0.1–3.0 nmol i.cv.) increased mean arterial blood pressure (MABP) and HR. CGRP (3.0 nmol i.cv.) also significantly increased both plasma norepinephrine and epinephrine concentrations. Pretreatment with 16.5 nmol i.cv. CGRP(8–37), a specific CGRP receptor antagonist, significantly inhibited the i.cv. CGRP (1.0 nmol)-induced increases in MABP and HR. Phenoxybenzamine inhibited the i.c.v. CGRP-induced increase in MABP, while propranolol suppressed the tachycardiac response to i.cv. CGRP. Chemical sympathectomy by 6-hydroxydopamine inhibited the increases in MABP and HR produced by i.cv CGRP. These results suggest that the central pressor and tachycardiac effects of i.c.v. CGRP are mediated by catecholamine release due to stimulation of sympathetic nervous system activity, possibly via specific CGRP receptors in the central nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170886
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  • 6
    Electronic Resource
    Electronic Resource
    Extraversion as a modifying factor in catecholamine and behavioral responses to ethanol (1994)
    Springer
    Psychopharmacology 115 (1994), S. 206-212 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol ; Catecholamines ; Extraversion ; Personality ; Performance ; Stress ; Epinephrine ; Norepinephrine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Individual differences in catecholamine response to stress and ethanol were tested in extraverts and introverts on the basis of Eysenck's drug postulate claiming that introverts would be less susceptible to sedative drugs like ethanol. Forty-four healthy males received either 0.8 g/kg ethanol mixed into a drink of caffeine-free cola or a respective placebo and were tested with a stressful mental arithmetic task before and 40 min after the intake of the drink. Plasma catecholamines were determined from blood samples drawn at five defined intervals from an indwelling cannula and self-ratings on deactivation, relaxation, and anxiety were obtained as well as quality and quantity of performance in the arithmetic task. Results showed that there was no difference in catecholamine stress responses between introverts (Ex −) and extraverts (Ex +) before the drink, but that the intake of the fluid (both ethanol and placebo) resulted in higher norepinephrine (NE) increases in Ex − than in Ex +. The combined effects of ethanol and stress yielded larger responses of longer durations in Ex− than in Ex +. The concomitant psychological changes showed larger reductions in anxiety and increases in relaxation as well as larger decrements in quality of performance (% errors) in introverts in spite of their higher catecholamine increases. Thus, the predictions on the basis of arousal theory could not be verified experimentally and the drug postulate has to be modified in the sense that introverts probably have a higher depletion of NE in the central nervous system under physical but not under mental stress which is reflected by higher levels in the plasma and respective decreases in performance and activation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244773
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  • 7
    Electronic Resource
    Electronic Resource
    α2-adrenoceptor blockade, pituitary-adrenal hormones, and agonistic interactions in rats (1994)
    Springer
    Psychopharmacology 115 (1994), S. 478-484 
    Details
    ISSN: 1432-2072
    Keywords: Aggression ; α2 Adrenoceptors ; Catecholamines ; ACTH ; Corticosterone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of adrenergic activation on aggressiveness and the aggression induced endocrine changes were tested in rats. α2 adrenoceptor blockers were used for enhancing activation of the adrenergic system, and changes in aggressiveness were tested in resident-intruder contests. Three experiments were conducted. In experiment 1, saline injected rats responded to the presence of an opponent by aggression and the increase in plasma ACTH and corticosterone. Intraperitoneal administration of 1 mg/kg CH-38083 (an α2 adrenoceptor antagonist) produced a several fold increase in clinch fighting and mutual upright scores, and also further enhanced the plasma ACTH and corticosterone response. In experiment 2, the effect of three doses (0.5, 1 and 2 mg/kg) of three different α2 adrenoceptor blockers CH-38083, idazoxan and yohimbine were tested. All the substances increased aggression at 0.5 and 1 mg/kg; at 2 mg/kg the effect of idazoxan and yohimbine disappeared, while with CH-38083 an additional increase was obtained. In yohimbine treated animals the enhancement of aggression was reduced already at 1 mg/kg. In experiment 3, indomethacin, a potent inhibitor of the catecholamine-induced ACTH release completely abolished the effects of the α2 adrenoceptor antagonist CH-38083: the intensity of agonistic interactions, as well as ACTH and corticosterone plasma concentrations, returned to control levels. The possible role of catecholamines and the stress hormones in the activation of aggression is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245571
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  • 8
    Electronic Resource
    Electronic Resource
    Psychophysiological and biochemical changes in patients with panic attacks in a defined situational arousal (1994)
    Springer
    European archives of psychiatry and clinical neuroscience 244 (1994), S. 86-92 
    Details
    ISSN: 1433-8491
    Keywords: Panic disorder ; Stress ; α-2-receptors ; Catecholamines ; Psychophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A group of 27 patients with panic disorder with or without agoraphobia were compared with 10 control subjects before stress exposure. No statistically significant differences between patients and controls were found for the cardiovascular parameters. Skin conductance level and skin conductance reaction were significantly higher in the patient group. They also showed higher self-ratings in behavioural symptoms associated with anxiety. There were statistically significant higher venous plasma levels of norepinephrine in patients than in controls, although the epinephrine levels were similar. The number of binding sites of α2 and the affinity of3H-yohimbine to the α2-receptors on intact thrombocytes was statistically significantly lower in patients compared to controls. Significant differences between the gender groups of patients and controls were found for electrodermal activity and epinephrine levels. These data add further evidence to an overshooting activation of the noradrenergic pathway in patients with panic disorder, possibly based on a dysregulation of α2-receptor
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02193524
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  • 9
    Electronic Resource
    Electronic Resource
    Evidence for the presence of a non-catecholamine, clonidine-displacing substance in crude, methanolic extracts of bovine brain and lung (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 351 (1994), S. 17-26 
    Details
    ISSN: 1432-1912
    Keywords: Key words Clonidine-displacing substance ; Methanolic extracts ; Bovine brain ; Bovine lung ; Catecholamines ; Histamine ; Monovalent cations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the present study we have prepared crude, methanolic extracts of bovine lung and bovine brain and, using radioligand binding assays in conjunction with a number of simple chromatographic techniques, provided evidence for the presence of a non-catecholamine ’clonidine-displacing substance‘ (CDS). The level of CDS in lung extracts (9 units/g wet weight n=11) is approximately 3 times that in the brain extracts. Furthermore, the effect of the crude, methanolic extracts are selective for non-adrenoceptor, imidazoline (labelled by [3H]-idazoxan) and α2-adrenoceptor binding sites (labelled by [3H]-clonidine); both extracts are 5–10-fold more potent displacers of ligand binding to α2-adrenoceptors compared with binding to opiate receptors (labelled by [3H]-etorphine) and practically inactive against α1-adrenoceptor and muscarinic binding sites (labelled by [3H]- prazosin and [3H]-quinuclidinyl benzilate, respectively). With the exception of the non-adrenoceptor, imidazoline binding assay, which used rat kidney membranes labelled by [3H]-idazoxan in the presence of the α2-adrenoceptor antagonist RS-15385-197, all radioreceptor assays involved bovine cerebral cortex membranes. Although the extracts contain catecholamines (brain only), histamine (lung only) and monovalent cations (both), which have the potential to interfere with the radioligand binding assays, their concentrations were too low to account for the effects observed. Preliminary attempts at purification of the extracts revealed that CDS activities from the two tissues are similar, i.e., practically insoluble in organic solvents at room temperature, not affected by either Sep-Pak C18 column or anion exchange resins but retained (along with the monovalent cations) by cation exchange resin. However, following chromatographic separation on a Biogel P2 column, the CDS-containing eluates are cation-free and exhibit qualitatively similar elution profiles. Future experiments will involve further purification of ’clonidine-displacing substance‘ to characterize its interaction with α2-adrenoceptor binding sites in greater detail and establish whether it has biological activity consistent with the properties implied by its effects in radioligand binding assays.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169059
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  • 10
    Electronic Resource
    Electronic Resource
    Lidocaine increases the number of β-adrenoceptors in neonatal rat cardiocytes in culture (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 349 (1994), S. 170-174 
    Details
    ISSN: 1432-1912
    Keywords: Antiarrhythmic drugs ; Receptor-regulation ; Adenylyl cyclase ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Some physiological functions of the heart are modulated through cardiac β-adrenoceptors. In acute myocardial infarction, ventricular arrhythmias occur frequently and class I antiarrhythmic drugs such as lidocaine are often administered continuously over long period. The aim of this study was to investigate the effects of long-term treatment with lidocaine on cardiac β-adrenoceptors. Ventricular cardiocytes from 2-day-old Wistar rat were cultured in the presence or absence of lidocaine, and, β-adrenoceptors of the membrane fraction of the cells were measured with a binding assay using [125I] -iodocyanopindolol ([125I] CYP) as a radioligand. When the cells were cultured in the presence of lidocaine at clinical or toxic concentrations, the binding of [125I]CYP to the cells increased in a concentration (10−5 mol/l-10−3 mol/l) — and time (12–72h) —dependent manner. The effect was due to an increase in maximum binding and was not due to a change in the dissociation constant for the ligand. The stimulation of adenylyl cyclase activity in the cell membrane by 1 μmol/l isoproterenol increased in lidocaine-treated cells. The increased number of receptors returned to the control level when the cells were cultured without lidocaine for a further 24 h. These results indicate that lidocaine up-regulates cardiac β-adrenoceptors at both clinical or toxic doses during the period of treatment. Other antiarrhythmic drugs such as disopyramide (Ia), mexiletine (lb) and flecainide (lc) also increased the number of β-receptors. It is suggested that when lidocaine or other class I antiarrhythmic drugs are used in cardiac disorders such as acute myocardial infarction and open-heart surgery, the responsiveness of the heart to catecholamines may be increased.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169833
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  • 11
    Electronic Resource
    Electronic Resource
    Uptake of 3H-catecholamines by rat liver cells occurs mainly through a system which is distinct from uptake1 or uptake2 (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 350 (1994), S. 130-142 
    Details
    ISSN: 1432-1912
    Keywords: Hepatocyte ; Catecholamines ; Uptake1 ; Uptake2 ; Renal organic cation transport ; Bilirubin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Isolated rat hepatocytes were incubated with 200 nmol/l 3H-(−)-noradrenaline or 50 nmol/l 3H(−)-adrenaline for 15 min, in Krebs-Henseleit solution at 37°C, gassed with 95% O2 5010 CO2. Monoamine oxidase and catechol-O-methyl transferase were inhibited withpargyline (500 μmol/l)and Ro 01-2812 (3,5-dinitropyrocatechol; 2 μol/l), respectively. Total radioactivity present in the cells, which corresponded mostly to intact 3H-amine, was measured. The content of 3H-noradrenaline increased with time of incubation, a plateau having been reached after 15 min of incubation. After 15 min of incubation,the cell: medium ratio for 3H-noradrenaline and 3H-adrenaline was 0.6–0.7. Desipramine (an inhibitor of the neuronal uptake of catecholamines — uptake,; 1 μmol/l) did not affect the uptake of either 3H-noradrenaline or 3H-adrenaline into hepatocytes. Corticosterone (an inhibitor of the extraneuronal uptake of catecholamines — uptake2; 40 μmol/l) slightly inhibited (by 28%) the uptake of 3H-adrenaline, and did not significantly reduce 3H-noradrenaline uptake. Probenecid (an inhibitor of the renal transport of organic anions; 100 μmol/l) did not influence the amount of either 3H-noradrenaline or 3H-adrenaline in hepatocytes. Cyanine 863 (an inhibitor of the renal transport of organic cations; 10 μmol/l) decreased by 62% the uptake of 3H-adrenaline into cells but did not significantly affect 3H-noradrenaline uptake. Bilirubin (a substrate of a hepatic transport for organic anions; 200 μol/l) produced a significant increase (50%) in the amount of 3H-noradrenaline and 3H-adrenaline present in the cells. When isolated hepatocytes were incubated in a sodium-free medium (sodium being replaced by choline or lithium) there was a very marked inhibition of 3H-noradrenaline and 3H-adrenaline uptake (by 85–97%). An increase in potassium content of the medium (from 6.6 to 50 mmol/l) did not affect the uptake of either 3H-amine into isolated cells. In conclusion, the uptake of catecholamines by isolated liver cells possesses characteristics that distinguish it from the classic uptake systems for catecholamines (uptake1 and uptake2): (1) it is sodium-dependent but not affected by desipramine; (2) it is only slightly sensitive to corticosterone and not affected by potassium-induced depolarization; (3) it is partially sensitive to cyanine 863. Moreover, the increase of 3H-amine content in the cells in the presence of bilirubin suggests the possibility of catecholamines being excreted from the hepatocytes through the bilirubin transporter. PhD student with a grant from JNICT (Programa Ciência)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00241086
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  • 12
    Electronic Resource
    Electronic Resource
    Evidence for norepinephrine cardiotoxicity mediated by superoxide anion radicals in isolated rabbit hearts (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 349 (1994), S. 295-300 
    Details
    ISSN: 1432-1912
    Keywords: NADH-fluorescence ; Catecholamines ; Norepinephrine ; Cardiotoxicity ; Cardioprotection ; Oxygen free radicals ; Superoxide dismutase ; Propranolol ; Vitamin C ; Captopril
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Catecholamines have been demonstrated to be cardiotoxic. Besides hemodynamic alterations, oxygen free radicals generated by the auto-oxidation of catecholamines might contribute to their deleterious effects. We examined the influence of exogenous norepinephrine (NE), after inhibiting functional alterations by alpha and beta-adrenoceptor blockade, on acute regional ischemia (MI). Method: We used isolated electrically-driven rabbit hearts with depleted catecholamine stores (reserpine 7.0 mg/kg i.p. 16–24 h before preparation, Langendorff, constant pressure: 70 cm H2O, Tyrode solution, Ca 2+ 1.8 mmol/l, 37°C, 185–200 beats/min). Repetitive MI, separated by a reperfusion period of 50 min, was induced by coronary artery branch ligature and quantitated from epicardial NADH-fluorescence photography. Starting after a reperfusion period of 20 min, isolated hearts were treated with NE (10−6 M), in the presence of propranolol (10−6 M), phentolamine (10−6 M) and vitamin C (3 × 10−8 M) in the perfusion buffer to prevent the functional effects of NE. The influence of the free radical scavenger superoxide dismutase (SOD) (30 U/ml) or captopril (10−6 M) on MI was also examined. Results: Left ventricular pressure or coronary flow were not significantly affected by either treatment (p〉0.05). Epicardial NADH-fluorescence area and intensity were, however, significantly enhanced by NE (+ 22%) (P〈0.05), although propranolol, phentolamine and vitamin C had no significant influence on MI (P〉0.05). SOD had no significant effect on MI in control hearts (P〉 0.05) but completely prevented MI enlargement by NE (P〉0.05). Captopril did not significantly affect MI in control hearts and did not inhibit MI enlargement by NE (P〈0.05). Conclusion: NE has deleterious effects .on MI in isolated rabbit hearts that are independent of functional alterations. This MI enlargement by NE is mediated by superoxide anion radicals since it could be prevented by SOD. Free radical scavenging properties reported for vitamin C, propranolol or captopril in several in-vitro systems are uneffective in preventing NE cardiotoxicity mediated by oxygen free radicals in isolated rabbit hearts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169296
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  • 13
    Electronic Resource
    Electronic Resource
    The distribution and colocalization of neuropeptides and catecholamines in nerves supplying the gall bladder of the toad, Bufo marinus (1994)
    Springer
    Cell & tissue research 277 (1994), S. 169-175 
    Details
    ISSN: 1432-0878
    Keywords: Gall bladder ; Neuropeptides ; Catecholamines ; Bufo marinus (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The indirect immunofluorescence technique was used to determine the distribution of peptide-containing axons in the gall bladder of the cane toad, Bufo marinus. In addition, the adrenergic innervation of the gall bladder was examined by use of immunoreactivity to the catecholamine-synthesizing enzyme, tyrosine hydroxylase, and glyoxylic acid-induced fluorescence. On the basis of peptide coexistence, two intrinsic populations of neurones and their projecting fibres could be distinguished substance P neurones and vasoactive intestine peptide neurones. Neither of these two types of neurones contained any other colocalized neuropeptides. Four populations of nerve fibres arising from cell bodies outside the gall bladder were identified: nerves containing colocalized galanin, somatostatin and vasoactive intestinal peptide; nerves containing colocalized calcitonin gene-related peptide and substance P; adrenergic nerves containing neuropeptide Y; and nerves containing only adrenaline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303093
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  • 14
    Electronic Resource
    Electronic Resource
    The distribution and colocalization of neuropeptides and catecholamines in nerves supplying the gall bladder of the toad, Bufo marinus (1994)
    Springer
    Cell & tissue research 277 (1994), S. 169-175 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Gall bladder ; Neuropeptides ; Catecholamines ; Bufo marinus (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The indirect immunofluorescence technique was used to determine the distribution of peptide-containing axons in the gall bladder of the cane toad, Bufo marinus. In addition, the adrenergic innervation of the gall bladder was examined by use of immunoreactivity to the catecholamine-synthesizing enzyme, tyrosine hydroxylase, and glyoxylic acid-induced fluorescence. On the basis of peptide coexistence, two intrinsic populations of neurones and their projecting fibres could be distinguished substance P neurones and vasoactive intestine peptide neurones. Neither of these two types of neurones contained any other colocalized neuropeptides. Four populations of nerve fibres arising from cell bodies outside the gall bladder were identified: nerves containing colocalized galanin, somatostatin and vasoactive intestinal peptide; nerves containing colocalized calcitonin gene-related peptide and substance P; adrenergic nerves containing neuropeptide Y; and nerves containing only adrenaline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303093
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  • 15
    Electronic Resource
    Electronic Resource
    Cardiovascular autonomic dysfunction in normotensive awake subjects with obstructive sleep apnoea syndrome (1994)
    Springer
    Clinical autonomic research 4 (1994), S. 57-62 
    Details
    ISSN: 1619-1560
    Keywords: Obstructive sleep apnoea syndrome ; Catecholamines ; Hypertension ; Cardiovascular reflexes ; Bradycardia ; Sympathetic activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cardiovascular autonomic function in normotensive awake patients with obstructive sleep apnoea syndrome was studied in 21 normotensive (mean age 48 ± 14 years), drug-free men with obstructive sleep apnoea syndrome. Cardiovascular reflex tests with continuous blood pressure monitoring and biochemical indices were performed the morning after a standard polygraphic sleep recording. A group of 20 agematched (mean age 49 ± 19 years) normal subjects was used as controls. The obstructive sleep apnoea syndrome patients showed higher heart rate and noradrenaline plasma levels (p 〈 0.05) at rest and a higher blood pressure response to head-up tilt (p 〈 0.01), suggesting sympathetic overactivity. Respiratory arrhythmia, baroreflex sensitivity index and Valsalva ratio were significantly lower in the obstructive sleep apnoea syndrome group (p 〈 0.01) whereas the decrease in heart rate induced by the cold face test was significantly higher (p 〈 0.05) showing a blunting of reflexes dependent on baroreceptor or pulmonary afferents with normal or increased cardiac vagal efferent activity. These abnormalities in autonomic regulation may predispose obstructive sleep apnoea syndrome patients to cardiovascular complications like hypertension and cardiac arrhythmias.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01828839
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  • 16
    Electronic Resource
    Electronic Resource
    Atrial natriuretic peptide response to postural change and medication in familial dysautonomia (1994)
    Springer
    Clinical autonomic research 4 (1994), S. 311-318 
    Details
    ISSN: 1619-1560
    Keywords: Atrial natriuretic peptide ; Catecholamines ; Familial dysautonomia ; Orthostatic hypotension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Circulating atrial natriuretic peptide (ANP) was assayed before and after postural change and exercise in 54 patients with familial dysautonomia (FD) and 20 controls. ANP levels were compared with blood pressure, heart rate, plasma catecholamines and parameters of renal function. Compared with controls supine FD subjects had elevated blood pressures, heart rates and ANP levels (39 ± 4 pg/ml vs. 23 ± 3 pg/ml,p 〈 0.01). With the erect posture and exercise in FD subjects, blood pressure fell below control values, with ANP lowered. In FD subjects, blood pressure was correlated with ANP levels when supine and when erect and with heart rate post exercise. In controls, ANP levels did not correlate with other parameters. In FD patients on metoclopramide, supine and erect blood pressure and ANP levels were higher. FD subjects treated with fludrocortisone, had elevated supine and erect noradrenaline (p 〈 0.05 andp = 0.06); and those on diazepam had lower erect and post exercise noradrenaline (p 〈 0.05), but ANP levels were similar. In conclusion, sympathetic denervation may increase FD patients' responsiveness to other regulators of cardiovascular integrity, such as ANP. In addition, circulating ANP and catecholamines in FD subjects appear to be influenced by commonly used medications, such as metoclopramide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01821531
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  • 17
    Electronic Resource
    Electronic Resource
    Effects of hydration state on plasma testosterone, cortisol and catecholamine concentrations before and during mild exercise at elevated temperature (1994)
    Springer
    European journal of applied physiology 69 (1994), S. 294-300 
    Details
    ISSN: 1439-6327
    Keywords: Dehydration ; Fluid intake ; Testosterone ; Cortisol ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This investigation examined the influence of pre-exercise hydration status, and water intake during low intensity exercise (5.6 km · h−1 at 5% gradient) in the heat (33° C), on plasma testosterone (TEST), cortisol (CORT), adrenaline (A), and noradrenaline (NA) concentrations at baseline (BL), pre-exercise (PRE), and immediately (IP), 24 h (24 P), and 48 h postexercise (48 P). Ten active men participated in four experimental treatments. These treatments differed in preexercise hydration status [euhydrated or hypohydrated (HY, −3.8 (SD 0.7)% body mass)] and water intake during exercise (water ad libitum or no water intake during exercise, NW). There were no significant changes in TEST, CORT, or A concentrations with time (BL, PRE, IP, 24 P, and 48 P), or among treatments. However, significant increases from BL and PRE plasma NA concentrations were observed at IP during all four treatment conditions. In addition, HY + NW resulted in significantly higher plasma NA concentrations at IP compared to all other treatments. These results suggest that moderate levels of hypohydration during prolonged, low intensity exercise in the heat do not influence plasma TEST, CORT, or A concentrations. However, plasma NA appears to respond in a sensitive manner to these hydration and exercise stresses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00392033
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  • 18
    Electronic Resource
    Electronic Resource
    Saliva electrolytes as a useful tool for anaerobic threshold determination (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 214-218 
    Details
    ISSN: 1439-6327
    Keywords: Catecholamines ; Blood lactate ; Ventilatory threshold ; Exercise ; Anaerobic threshold
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of the present study was to determine the anaerobic threshold by analysis of changes in saliva composition during an incremental exercise test on a cycle ergometer. Thirteen healthy males underwent a submaximal test with an initial load of 50 W and load increases of 50 W per 3 min, until capillary blood lactate exceeded 4 mmol · l−1. A maximal test for maximum O2 uptake (VO2max) determination (initial load of 100 W and load increases of 50 W per 2 min) was also performed. Saliva and blood samples were obtained only in the submaximal test. Saliva threshold (Thsa) was defined as the point at which the first increase in either Cl− or Na+ occurred. Catecholamine threshold (Thca) was defined as the point at which a nonlinear increase occurred in either adrenaline or noradrenaline. The lactate (Thla) and ventilatory (Thve) thresholds were determined according to published criteria. No significant differences were found between Thsa values and the other methods of threshold determination. A high correlation was found between Thsa and Thla (r = 0.82, P 〈 0.01), and Thsa and Thca (r = 0.75, P 〈 0.05). These results support the validity of Thsa as a new method for noninvasive determination of the anaerobic threshold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376769
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  • 19
    Electronic Resource
    Electronic Resource
    Hypoxia and training-induced adaptation of hormonal responses to exercise in humans (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 303-309 
    Details
    ISSN: 1439-6327
    Keywords: Catecholamines ; Insulin ; Growth hormone ; ACTH ; Erythropoietin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To establish whether or not hypoxia influences the training-induced adaptation of hormonal responses to exercise, 21 healthy, untrained subjects [26 (2) years, mean (SE)] were studied in three groups before and after 5 weeks' training (cycle ergometer, 45 min· day−1, 5 days· week−1). Group 1 trained at sea level at 70% maximal oxygen uptake ( $$\dot V$$ O2max), group 2 in a hypobaric chamber at a simulated altitude of 2500 m at 70% of altitude $$\dot V$$ O2max, and group 3 at a simulated altitude of 2500 m at the same absolute work rate as group 1. Arterial blood was sampled before, during and at the end of exhaustive cycling at sea level (85% of pretraining of $$\dot V$$ O2max). $$\dot V$$ O2 increased by 12 (2)% with no significant difference between groups, whereas endurance improved most in group 1 (P 〈 0.05). Training-induced changes in response to exercise of noradrenaline, adrenaline, growth hormone, β-endorphin, glucagon, and insulin were similar in the three groups. Concentrations of erythropoietin and 2,3-diphosphoglycerate at rest did not change over the training period. In conclusion, within 5 weeks of training, no further adaptation of hormonal exercise responses takes place if intensity is increased above 70% $$\dot V$$ O2max. Furthermore, hypoxia per se does not add to the training-induced hormonal responses to exercise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571448
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  • 20
    Electronic Resource
    Electronic Resource
    Phaeochromocytoma: Intraoperative changes in blood pressure and plasma catecholamines (1994)
    Springer
    Clinical autonomic research 4 (1994), S. 167-173 
    Details
    ISSN: 1619-1560
    Keywords: Phaeochromocytoma ; Catecholamines ; Blood pressure ; Hypertension ; Anaesthesia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to assess the relationship between changes in plasma catecholamine concentrations and intraarterial blood pressure (BP) measured simultaneously during resection of phaeochromocytoma (n = 14). Arterial plasma concentrations of noradrenaline (NA), adrenaline (A) and dopamine (DA) were measured by a radio-enzymatic method. Arterial NA concentrations (pmol/ml; median and Wilcoxon 95% CI) were 71.8 (46,162) before induction of anaesthesia, 113.0 (79,231) after intubation, 375.0 (285,931) during tumour handling and 32.5 (18,88) following tumour removal. Simultaneous mean BP values (mmHg; Mean ± SEM) were 119 ± 8, 114 ± 7, 159 ± 7 (p = 0.0001) and 72 ± 6 (p 〈 0.0001) respectively. At the time of tumour handling there was a weak correlation between plasma NA and A combined and mean BP (r = 0.583,p = 0.029) and a stronger correlation between log plasma NA and A combined and pulse pressure (r = 0.749,p = 0.008). The very large rises in plasma catecholamine concentrations and in BP are likely to have been causally related. Individual patients maintained a constant ratio of NA to A in plasma from pre-induction to tumour handling (r = 0.916,p 〈 0.0001). The maintenance of a constant NA: A ratio suggests that the pattern of catecholamine synthesis and release may be a characteristic of the individual tumour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01826182
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  • 21
    Electronic Resource
    Electronic Resource
    Lactate and catecholamine responses in male and female sprinters during a Wingate test (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 362-366 
    Details
    ISSN: 1439-6327
    Keywords: Supramaximal exercise ; Lactate ; Catecholamines ; Sex ; Sprinters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A total of six male and six female sprinters at the same national competition level and aged 18–20 years performed a force/velocity test and a 30-s supramaximal exercise test (Wingate test) on 2 different days, separated by a maximal interval of 15 days. The maximal anaerobic power (W max) was determined from the force/velocity test, and the mean anaerobic power (W) from the Wingate test. Immediately after the Wingate test, a 5-ml venous blood sample was drawn via a heparinized catheter in an antebrachial vein for subsequent catecholamine (adrenaline and noradrenaline) analysis. After 5 min recovery a few microlitres of capillary blood were also taken for an immediate lactate determination. Even expressed per kilogram lean body mass,W max andW were significantly lower in women. The lactate and adrenaline responses induced by the Wingate test were also less pronounced in this group whereas the noradrenaline levels were not significantly different in men and women. Above all, very different relationships appeared between lactate, adrenaline, noradenaline and W according to sex. Thus, as reported by other authors, the adrenergic response to a supramaximal exercise seemed to be lower in women than in men. Nevertheless a different training status between the two groups, even at same national competition level, could not be excluded and might contribute, at least in part, to the gender differences observed in the present study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571458
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  • 22
    Electronic Resource
    Electronic Resource
    Aerobic fitness and sympatho-adrenal response to short-term psycho-emotional stress under field conditions (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 418-424 
    Details
    ISSN: 1439-6327
    Keywords: Aerobic fitness ; Stress ; Physical strain ; Sympatho adrenal response ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A possible relationship between aerobic fitness (AF), measured by maximal cycle ergometry (CE) and sympatho-adrenal response to acute, short lasting psycho-emotional stress was investigated by monitoring heart rate (f c) and excretion of catecholamines. The activation of the sympatho-adrenal system was characterised by the noradrenaline : adrenaline ratio. A group of 11 healthy men [22.8 (SD 2.52) years] lived under identical environmental conditions; their mean maximal oxygen uptake ( $$\dot VO_{2max} $$ ) was 47.1 (SD 3.9) ml · min−1 · kg−1. After the physiological and psychological laboratory tests had been completed thef c of the subjects was monitored continuously during the “guerilla slide” and “parachute jump by night”, two emotionally stressful military tasks. Maximalf c (f c, max) attained during these events was 84.5% and 83% off c, max during CE (f c, max, CE), respectively. A significant relationship (r=−0.92,P〈0.0002) betweenf c, max reached during the stressful tasks and $$\dot VO_{2max} $$ was found only for the guerilla slide, which was preceded by physical strain, sleep deprivation and energy deficit. One subject with some prior experience in parachuting showed the lowestf c response and the lowest sympatho-adrenal activation in both events, independent of the degree of AF. In conclusion, AF was found to influence the sympatho-adrenal and fc response to acute, short-lasting emotional stress when the stressful event was aggravated by preceding physical strain, the magnitude of the stress response depending largely on individual experience and effective mechanisms for coping with specific stimuli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00843739
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  • 23
    Electronic Resource
    Electronic Resource
    Cardiovascular responses of cardiac transplant patients to arm and leg exercise (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 441-444 
    Details
    ISSN: 1439-6327
    Keywords: Cardiac output ; Heart rate ; Stroke volume ; Catecholamines ; Autonomic nervous system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This investigation compares the cardiovascular responses of normal (n=10) and cardiac transplant (n=14) subjects to peak arm and leg exercise. It also tests the hypothesis that the higher heart rate (f c) in normal subjects during light (30 W) submaximal arm versus leg exercise is due to cardiac innervation. In cardiac transplant patients, power output, oxygen consumption $$\dot VO_2 $$ ,f c and rate pressure product were 54%, 28%, 7%, and 8% lower during peak arm than leg exercise, respectively. In normal subjects, power output, $$\dot VO_2 $$ ,f c and rate pressure product were 61%, 33%, 8%, and 11% lower during peak arm than leg exercise, respectively. In cardiac transplant patients there was no significant difference in absolutef c during submaximal arm and leg exercise. In normal subjects, absolutef c during arm and leg exercise was [mean (SD)] 97 (4) beats · min−1 and 92 (4) beats · min−1, respectively (P=0.07). Plasma noradrenaline was increased more during arm than leg exercise in both cardiac transplant and normal subjects. Maximal leg testing is useful when determining the capacity of cardiac transplant patients to perform arm work. The higher absolutef c reported by other investigators for normal subjects during submaximal arm versus leg exercise may be mediated by cardiac innervation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00843743
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  • 24
    Electronic Resource
    Electronic Resource
    Cardiovascular effects of Atenolol, Scopolamine and their combination on healthy men in Finnish sauna baths (1994)
    Springer
    European journal of applied physiology 69 (1994), S. 10-15 
    Details
    ISSN: 1439-6327
    Keywords: Atenolol ; Catecholamines ; Finnish sauna bath ; Heart rate ; Scopolamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Indicators of cardiovascular strain were studied in 12 healthy young men under the influence of drugs affecting the autonomic nervous system during the course of taking a sauna bath. There were four bath sessions: one without a drug (control) and three with drug pretreatment (Atenolol 50 mg or Scopolamine 0.3 mg or their combination taken orally 2 h before the bath). The time spent in the hot room depended on the subjective rating of heat stress. Its mean duration at a temperature of 88°C (dry bulb) was 22 (range 14–33) min and did not differ significantly among the sessions. In the Atenolol experiment the mean resting heart rate before the bath was significantly lower (P 〈 0.001, ANOVA of repeated measures) than in the other experiments. The increase in heart rate per minute of heat exposure was significantly lower (P 〈 0.001) in the Atenolol experiment and higher (P=0.017) in the Scopolamine experiment than in the other experiments. The systolic blood pressure increased more slowly (P=0.004) and the diastolic pressure decreased less (P=0.02) in the Atenolol experiment than in the other experiments. Heart rate and blood pressure returned to their initial levels during the 30-min recovery after the heat exposure. The plasma noradrenaline concentrations increased approximately twofold during all of the bath sessions, whereas the plasma adrenaline and serum thromboxane B2 concentrations showed no consistent alterations. A small oral dose of Scopolamine alone or in combination with Atenolol produced no marked cardiovascular strain in healthy men during a sauna bath.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00867920
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  • 25
    Electronic Resource
    Electronic Resource
    Plasma catecholamines during endurance exercise of different intensities as related to the individual anaerobic threshold (1994)
    Springer
    European journal of applied physiology 69 (1994), S. 16-20 
    Details
    ISSN: 1439-6327
    Keywords: Individual anaerobic threshold ; Maximal lactate steady state ; Catecholamines ; Heart rate ; Ergometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The study investigated the concentrations of free plasma catecholamines (CAT), adrenaline and noradrenaline, in comparison to heart rate and lactic acid concentrations during endurance exercises (EE) of different intensities related to the individual anaerobic threshold (IAT). A group of 14 endurance trained male athletes took part in the tests on a treadmill. After an exhausting incremental graded test (increasing 0.5 m · s−1 every 3 min) to determine t he IAT, the subjects performed EE of 45 min in randomized order with intensities of 85%, 95%, 100% and 105% (E85–E105) of the IAT. The heart rate and CAT increased continuously during all EE. The CAT reacted sensitively to EE above IAT (E105) and showed an overproportional increase in comparison to EE performed with an intensity at or below IAT. At the same time, at exercise intensities up to IAT (E85–E100) a lactate steady state was observed whereas mean lactate concentrations increased during E105. The changes of lactate concentration allowed a better differentiation between E85–E100 as CAT measurements. In E95, E100 and E105 there was a partial overlap of heart rate, which in contrast to lactate concentration only differed by about 5%, so that small variations in heart rate could have coincided with considerable differences of exercise intensity when working at intensities near or above IAT. It was concluded that the range of IAT seemed to represent a real physiological breakpoint which corresponded to the aerobic-anaerobic transition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00867921
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  • 26
    Electronic Resource
    Electronic Resource
    Hormone changes induced by 37.5-h head-down tilt (−6°) in humans (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 497-503 
    Details
    ISSN: 1439-6327
    Keywords: Head-down tilt ; Plasma volume ; Atrial natriuretic peptide ; Renin ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Endocrine regulation of hormones and electrolytes during 37.5 h of −6° head down tilt (HDT) was studied in 13 men. The acute effects of simulated weightlessness are today well documented, but no study has been made concerning the hormone changes between 12 h and 2 days of HDT. Plasma volume showed a maximal increase of 9.23 (SEM 1.97) % after 6.5 h (P〈0.01) and had returned to prestudy levels after 13.5 h of HDT. From 1.5 h to 4 h of HDT, C-terminus and N-terminus atrial natriuretic peptide (ANP) concentrations in plasma were increased by about 50% (P〈0.01) and thereafter declined to pre-HDT levels. Plasma renin activity (PRA) was decreased by 47% (P〈0.05) after 4 h of HDT; PRA increased after 23.5 h to 60%; noradrenaline concentration decreased immediately and remained low up to 37.5 h. Diuresis and natriuresis were evident during the 1st day of HDT, resulting in a marked increase in the urinary Na+. These results showed that the initial hormone (ANP, PRA) changes during HDT did not last more than 13.5 h and that after 24 h a new state would seem to have been established to adapt the body to hypovolaemia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00599519
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  • 27
    Electronic Resource
    Electronic Resource
    Volume- and catecholamine-dependent regulation of Na/H antiporter and unidirectional potassium fluxes in Salmo trutta red blood cells (1994)
    Springer
    Journal of comparative physiology 164 (1994), S. 135-140 
    Details
    ISSN: 1432-136X
    Keywords: Na K-pump ; Na/H exchange ; Catecholamines ; Cell volume ; Fish erythrocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract β-Adrenergic- and volume-dependent regulation of 22Na influx and 86Rb influx and efflux in erythrocytes of brown trout (Salmo trutta m. lacustris) were studied. Norepinephrine (10-6 mol·1-1) increased the rate of 22Na influx 10-to 20-fold via the activation of a Na/H exchanger (ethyl isopropyl amiloride inhibited component of 22Na influx). Unlike carp erythrocytes the activity of the Na, K-pump (ouabain-inhibited 86Rb influx) was only slightly (25–35%) increased by norepinephrine. The norepinephrine-induced increment of Na, K-pump activity was completely abolished by ethyl isopropyl amiloride thus indicating that this effect was mediated by Na/H exchanger-induced increase of intracellular Na+ concentration. Cell shrinkage in hyperosmotic media resulted in a several-fold activation of the Na/H exchanger. Cell swelling in hypotonic media increased both the rate of K, Cl-cotransport [((dihydroindenyl)oxy)alcanaic acidsensitive components of 86Rb influxe and efflux] and passive permeability (leakage) of erythrocyte membranes for Na+ and K+. No volume-dependent regulation of Na, K, 2Cl-cotransport (bumetanide-sensitive components of 86Rb fluxes) was found. It may be concluded that the regulation of monovalent cation transport in erythrocytes of fast-moving (carnivorous) brown trout differs essentially from that in slowly moving (herbivorous) carp.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301655
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  • 28
    Electronic Resource
    Electronic Resource
    Influence of initial respiratory status on the short-and long-term activity of the trout red blood cell β-adrenergic Na+/H+ exchanger (1994)
    Springer
    Journal of comparative physiology 164 (1994), S. 383-389 
    Details
    ISSN: 1432-136X
    Keywords: Acid-base status ; Blood gases ; Catecholamines ; Na+/H+ exchange ; Trout, Oncorhynchus mykiss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The effects of ambient O2 partial pressure and CO2 partial pressure on the intensity of rainbow trout (Oncorhynchus mykiss) red blood cell β-adrenergic Na+/H+ exchange were investigated. This was accomplished in vitro by continuously monitoring whole blood extracellular pH, partial pressures of O2 and CO2 and by measuring red blood cell water content and Na+ concentration before and 30 min after the addition of a catecholamine mixture (final nominal concentrations: 250 nmol·l-1 adrenaline and 20 nmol·l-1 noradrenaline). The experiments were performed under six different initial conditions combining two ambient partial pressures of CO2 (1.50 and 6.75 torr) and three ambient partial pressures of O2 (15, 30 and 150 torr). The activation of red blood cell Na+/H+ exchange (as indicated by marked reductions of whole blood pH) was followed by transient reductions in blood partial pressures of CO2 and O2 (2 min) resulting from the shift of the CO2/HCO3 - equilibrium within the cell and the subsequent binding of O2 to the haemoglobin. The initial reduction in blood CO2 partial pressure was followed by a rise reflecting the titration of plasma HCO3 - by extruded H+. At low partial pressure of CO2 (1.50 torr) there was a pronounced stimulatory effect of hypoxia on the initial intensity of the extracellular acidification (5 min), whereas at high CO2 partial pressure (6.75 torr) hypoxia actually lowered the extent of the initial acidification. In all cases, Na+/H+ exchange activation was accompanied by increases in cell water content and red blood cell Na+ levles when measured 30 min after addition of catecholamines. Both hypercapnia and hypoxia increased the magnitude of these changes although the largest changes in cell water content and Na+ levels were observed under hypercapnic conditions. Thus, the long-term activity (as determined by measuring cell water and Na+ levels) of the Na+/H+ exchanger was enhanced both by hypercapnia and hypoxia regardless of the initial CO2 partial pressure. The initial activity (5 min), on the other hand, although stimulated by hypercapnia was influenced by hypoxia in opposing directions depending upon the initial CO2 partial pressure of the blood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302554
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  • 29
    Electronic Resource
    Electronic Resource
    Compliance and smooth muscle reactivity of rainbow trout (Oncorhynchus mykiss) vessels in vitro (1994)
    Springer
    Journal of comparative physiology 163 (1994), S. 657-663 
    Details
    ISSN: 1432-136X
    Keywords: Fish veins ; Contraction ; Catecholamines ; Vasoactive peptides ; Trout, Oncorhynchus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Systemic veins have a profound influence on cardiac output in mammals. Venoregulatory mechanisms have not been adequately studied in fish and their existence has been questioned. In the present study, two characteristics of vascular mechanics, compliance and agonist-induced tension development, were investigated in rainbow trout vessels in vitro. Rapid compliance in the anterior cardinal vein and efferent branchial artery was calculated from step-wise changes in the volume-pressure curve of isolated vessel segments. Agonist-induced tension development was examined in four veins; anterior and posterior cardinals, intestinal and duct of Cuvier. Venous compliance was not altered in response to epinephrine, norepinephrine or angiotensin II, while efferent branchial artery compliance was decreased by 10-6 mol·l-1 epinephrine and norepinephrine but not angiotensin II. The ratios of venous to arterial compliance in vessels from two rainbow trout strains were similar (21:1 and 32:1) and consistent with the ratio reported for mammalian viens (24:1). Trout veins contracted in response to agonists in both an, agonist- and vesselspecific manner. The greatest tension per vessel wet weight was produced in anterior cardinal vein. The response pattern of anterior cardinal vein and duct of Cuvier were similar; acetylcholine, arginine vasotocin, epinephrine and norepinephrine, and the thromboxane A2 agonist, U-44,069, produced approximately identical contractions, whereas angiotensin II was virtually ineffective. Conversely, angiotensin II was more potent than epinephrine in posterior cardinal vein. In cumulative dose-response experiments, epinephrine was equipotent in anterior cardinal vein and duct of Cuvier, whereas the latter was less sensitive to acetylcholine. Both atrial natriuretic peptide and sodium nitroprusside relaxed precontracted veins. This is the first study to determine compliance in fish vessels and the contractile nature of different rainbow trout veins. These findings suggest that venous tone and therefore cardiac output in fish may be regulated by neural or humoral mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00369516
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  • 30
    Electronic Resource
    Electronic Resource
    Stress response in two Antarctic teleosts (Notothenia coriiceps Richardson andChaenocephalus aceratus Lönnberg) following capture and surgery (1994)
    Springer
    Journal of comparative physiology 164 (1994), S. 482-491 
    Details
    ISSN: 1432-136X
    Keywords: Catecholamines ; Capture ; Surgery ; Antarctic teleosts ; Icefish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Blood chemistry and haematological parameters have been determined in two Antarctic teleosts,Notothenia coriiceps Richardson andChaenocephalus aceratus Lönnberg, held at around 1°C.Notothenia coriiceps has a low haemoglobin content compared to tem-perate-zone species, whereasC. aceratus apparently lacks respiratory pigments. Blood samples were obtained by cardiac puncture following landing or using chronically implanted post-branchial arterial cannulae. Although both species showed a similar acidosis on capture (arterial pH as low as 7.5 versus the final recovery value of around 7.9),C. aceratus took 48 h to reestablish baseline values whileN. coriiceps recovered within 12 h, despite initially showing a greater degree of hypercapnic hypoxia. Surgery led to a more severe disturbance of acid-base regulation inN. coriiceps thanC. aceratus (arterial pH of 7.5 versus 7.8) but needed only half as long for recovery. A progressive decrease in arterial oxygen tension and increase in arterial carbon dioxide tension (both more pronounced inN. coriiceps) with level of acidosis was observed down to arteria pH 7.2 InC. aceratus this was accompanied by a rise in blood lactate (up to 10 mmol·1-1 in some individuals), whileN. coriiceps showed only a modest and transient lactacidosis. Stress inN. coriiceps therefore induces primarily a respiratory, rather than a metabolic acidosis, whereas inC. aceratus both components are present. A differential response to stress is also indicated by an elevated, though low noradrenaline titre inN. coriiceps following surgery and capture, whileC. aceratus was little affected by surgery. However, both species show an unusually weak catecholamine response to induced stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00714586
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  • 31
    Electronic Resource
    Electronic Resource
    Adrenal medulla and Parkinson's disease (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 29 (1994), S. 151-154 
    Details
    ISSN: 1059-910X
    Keywords: Catecholamines ; Human ; Mouse ; MPTP ; Antiparkinsonian medication ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Parkinson's disease has been described as a multisystem disorder that includes alterations in the function of the autonomic nervous system. The activity of the adrenal medulla in this disease has not been thoroughly investigated. Previous reports are reviewed that demonstrate that the adrenal medullae of parkinsonian patients are compromised, having a decreased content of all catecholamines and several neuropeptides. An animal model was used to investigate whether the observations made in human patients were related to extended treatment with antiparkinsonian medications or were a natural concomitant of the disease. Administration of L-dopa and/or carbidopa to C57BL mice for 4-16 weeks had no significant effect on the level of any of the adrenal medullary catecholamines. Treatment with MPTP 4-16 weeks prior to sacrifice did not deplete adrenal medullary catecholamines in these animals, thus not fully mimicking Parkinson's disease in this animal model. The only significant effect was an interaction between group (MPTP or control) and treatment with antiparkinsonian medications; L-dopa, in the absence and presence of carbidopa, had opposite effects in the two groups. Based primarily on the lack of effect of antiparkinsonian medications on adrenal medullary catecholamines, it was concluded that the adrenal medullary depletion observed in human patients was a peripheral concomitant of Parkinson's disease. © 1994 Wiley-Liss, Inc.
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    URL: http://dx.doi.org/10.1002/jemt.1070290212
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    Chemosensitivity, plasticity, and functional heterogeneity of paraganglionic cells in the rat coeliac-superior mesenteric complex (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 29 (1994), S. 112-119 
    Details
    ISSN: 1059-910X
    Keywords: Prevertebral ganglia ; Catecholamines ; Tyrosine hydroxylase ; Dopamine β hydroxylase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Chemosensitivity and plasticity of paraganglionic cells in the rat coeliac-superior mesenteric complex (CSMC) were investigated at a basal state of normoxia (21% O2) and after long-term moderate hypoxia (10% O2, 14 days). Chemical sympathectomy previous to hypoxia was performed to destroy principal ganglionic neurons and thus to allow measurement of the norepinephrine and dopamine content of paraganglionic cells.At the basal state, the CSMC contained dopaminergic (TH+/DBH-) and noradrenergic (TH+/DBH+) paraganglionic cells, the majority being of the noradrenergic type. After 14 days of hypoxia, this ratio was reversed and dopaminergic cells predominated, as indicated by a twofold increase of TH+ cells and a twofold decrease of DBH+ cells. Biochemically, hypoxia produced an increase in the content (1.6-fold) and utilization (1.4-fold) of dopamine as well as a smaller increase in the content of norepinephrine, with no change in its utilization rate. The dopaminergic activation induced by hypoxia persisted after sympathectomy with guanethidine.It is concluded that paraganglionic cells in the CSMC display a chemosensitive function. Furthermore, our findings indicate that paraganglionic cells are differentially affected by hypoxia, depending on their distribution and the nature of their neuromodulators. The alterations induced by hypoxia point out the phenotypic plasticity developed by paraganglionic cells in adaptation to hypoxia and further demonstrate the functional heterogeneity of this autonomic cell population in the rat CSMC. © 1994 Wiley-Liss, Inc.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070290208
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    Different effects of eicosapentaenoic acid and olive oil on blood pressure, intracellular free platelet calcium, and plasma lipids in patients with essential hypertension (1993)
    Springer
    Journal of molecular medicine 71 (1993), S. 628-633 
    Details
    ISSN: 1432-1440
    Keywords: Blood pressure ; Catecholamines ; Eicosapentaenoic acid ; Essential hypertension ; Intracellular free calcium ; Lipids ; Platelets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a randomized, double-blind, crossover study our specific aim was to examine the effects of a dietary fish oil or olive oil supplementation on blood pressure, intracellular free platelet calcium, plasma lipoproteins, and circulating vasoactive substances such as norepinephrine, epinephrine, and renin in patients with essential hypertension. Ten hypertensive patients (WHO classes I, II) were randomly assigned to receive 9 g fish oil or 9 g olive oil daily for 6 weeks after a 4-week baseline period. The 6-week treatment periods were separated by a 4-week wash-out. During treatment with fish oil diastolic blood pressure decreased from 103±1 to 98±2 mmHg (P〈0.05) but did not change significantly during olive oil intake. Systolic blood pressure was not affected by either treatment. Intracellular free platelet calcium decreased in patients receiving fish oil (from 102±8 nM to 86±6 nM, P 〈 0.05) but was not significantly altered by olive oil treatment. In contrast, the dose-response curve for thrombin-induced intracellular free platelet calcium was not altered by the fish oil enriched diet. Plasma triglycerides decreased by approximately 40% in the fish oil group while low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and total cholesterol were not altered. Renin activity, norepinphrine, and epinephrine in plasma were not influenced by fish oil supplementation. We conclude that a moderate increase in dietary fish oil reduces diastolic blood pressure, intracellular free platelet calcium, and plasma triglycerides in patients with essential hypertension. The decrease in basal intracellular free platelet calcium concentration does not seem to be due to a diminished responsiveness of the calcium messenger system to thrombin.
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    URL: http://dx.doi.org/10.1007/BF00184490
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    Β-Adrenergic receptors in psoriasis: evidence for down-regulation in lesional skin (1993)
    Springer
    Archives of dermatological research 285 (1993), S. 300-304 
    Details
    ISSN: 1432-069X
    Keywords: Beta-adrenergic receptors ; Epidermis ; Keratinocytes ; Catecholamines ; Calcium ; Psoriasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Lesional psoriatic skin displays reduced responsiveness to Β-adrenergic stimulating agents. To elucidate whether the receptor protein itself is responsible for this, lesional and non-lesional psoritatic skin was investigated ex vivo for maximal Β-adrenergic binding density (B max) and Β-adrenergic binding affinity (K D). Epidermal crude membrane homogenates (ECMH) were prepared from split-thickness skin biopsies and saturated with the lipophilic Β-adrenergic antagonist (—)-125I-iodocyanopindolol (ICYP) as radioligand. Specific binding was saturable and Scatchard transformation of the binding data revealed a homogeneous class of Β-adrenergic receptors in all nine experiments. The maximal Β-adrenergic binding density was significantly less in lesional than in non-lesional psoriatic skin (B max=49.7 ± 7.2 fmol/mg protein vs. 67.1 ± 2.2 fmol/mg protein, n=9, P〈0.05). The binding affinity was similar in lesional and in non-lesional skin (K D=9.0 ± 1.5 pmol/l vs. 8.0 ± 0.9 pmol/l). These results could at least partially explain the reduced responsiveness of the Β-adrenergic system in lesional psoriatic skin seen after stimulation with Β-adrenergic agonists.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00371601
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    Comparison of the hemodynamic effects of hydroxocobalamin and cobalt edetate at equipotent cyanide antidotal doses in conscious dogs (1993)
    Springer
    Intensive care medicine 19 (1993), S. 26-32 
    Details
    ISSN: 1432-1238
    Keywords: Cyanide ; Hydroxocobalamin ; Cobalt edetate ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objectives The hemodynamic effects of two cyanide antidotes, hydroxocobalamin and cobalt edetate were compared. Design This experimental study was performed in chronically instrumented conscious dogs and at equipotent cyanide antidotal doses (hydroxocobalamin 70 mg·kg−1; cobalt edetate 10.5 mg·kg−1). Results Peak plasma cobalt concentrations did not differ in the two groups (412±183 vs 400±160 μmol·1−1). Hydroxocobalamin induced a slight increase in mean arterial pressure (+17±9%,p〈0.05) and systemic resistance (+19±15%,p〈0.05). In contrast, cobalt edetate induced an increase in heart rate (+78±33%,p〈0.05), in cardiac output (+63±39%,p〈0.05), and in maximum rise of left ventricular pressure (+33±15%,p〈0.05), did not modify mean arterial pressure, and decreased systemic resistance (−36±15%,p〈0.05). These hemodynamic effects were associated with an increase in plasma catecholamine concentrations (epinephrine: 2524±3025 vs. 58±37 pg·ml−1,p〈0.05; norepinephrine: 1106±609 vs. 343±146 pg·ml−1,p〈0.05), which in contrast remained unchanged after hydroxocobalamin administration. Cobalt edetate also induced an increase in blood glucose concentrations (9.9±1.9 vs. 6.1±1.2 mmol·l−1,p〈0.05) and a moderate metabolic acidosis, whereas hydroxocobalamin did not. After adrenergic (α1,β) and cholinergic receptor blockade, cobalt edetate did not modify heart rate and various indices of cardiac function, suggesting that it has no direct cardiac effects. Conclusion Considering its lack of hemodynamically relevant effects, these results indicate that hydroxocobalamin is potentially a safer cyanide antidote than cobalt edetate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01709274
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    COMT inhibitors and metabolism of fluorodopa enantiomers in aggregating cell cultures (1993)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 348 (1993), S. 582-585 
    Details
    ISSN: 1432-1912
    Keywords: Aggregating brain cell cultures ; Catechol-O-methyltransferase ; (COMT) inhibition ; Fluoro-DOPA ; Catecholamines ; OR 486 ; CGP 28014
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Organotypic primary cell cultures of fetal rat brain were used as a model system to study the effect of COMT inhibitors on the cerebral metabolic conversions of fluoro-DOPA enantiomers. The selective COMT inhibitors OR 486 and CGP 28014 were used in conjunction with 5F-l-DOPA, 6F-l-DOPA and 6F-d-DOPA as substrates. Methylation can be clearly reduced by application of OR 486 at nanomolar level, without inhibition of AADC and MAO. The uptake of the substrate is unchanged. CGP 28014, already known to be active only in vivo, has no influence on the metabolic conversion rates of the fluoro-DOPA isomers. These results show that use of this culture system allows statement concerning the in vitro activity of COMT inhibitors. It has not been possible to show an increase of absolute levels of decarboxylation products due to inhibition of COMT, however, but the reduction in levels of methylated product itself may have significance for PET studies of the human brain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167233
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    Cardiovascular and sympathoadrenal responses to intrathecal injection of neuropeptide K in the conscious rat (1993)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 347 (1993), S. 42-49 
    Details
    ISSN: 1432-1912
    Keywords: Spinal cord ; Tachykinins ; Neuropeptide K ; Cardiovascular system ; Catecholamines ; Neuropeptide Y
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the conscious freely moving rat, the intrathecal (i.t.) injection of neuropeptide K (NPK; 0.65 to 6.5 nmol), at T-9 spinal cord level, produced dose-dependent and prolonged (〉 3 h) increases in mean arterial blood pressure (MAP) and heart rate (HR). The cardiovascular response to 3.25 nmol NPK was less sustained when injected at T-2 level. The cardiovascular response to 3.25 nmol NPK (T-9 level) was correlated with increases in plasma levels of noradrenaline, adrenaline and neuropeptide Y (NPY), and was significantly reduced by the prior i.v. administration of inhibitors of either α-adrenoceptors (1 mg/kg, phentolamine), α1-adrenoceptors (1 mg/kg, prazosin), β1-adrenoceptors (1 mg/kg, metoprolol) or angiotensin converting enzyme (10 mg/kg, captopril). The cardiovascular response to NPK was also significantly reduced in rats that had undergone, 48 h earlier, bilateral adrenalectomy or to a greater extent sympathectomy with 6-hydroxydopamine. Whereas NPK-induced release of adrenaline was abolished by adrenalectomy, that of neuropeptide Y and noradrenaline was blunted by either treatment. The results suggest that the cardiovascular effect of i.t. NPK is mediated by the stimulation of the sympathoadrenal system and the release of angiotensin. Sympathetic fibers may play a greater role than the adrenal medulla in the cardiovascular response to NPK. It appears that neuropeptide Y derives from both sympathetic fibers and adrenal medullae. Hence, if released in the spinal cord, NPK may play an important role in cardiovascular and sympathoadrenal regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00168770
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    The pharmacology of descending responses evoked by thoracic stimulation in the neonatal rat spinal cord in vitro (1993)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 347 (1993), S. 643-651 
    Details
    ISSN: 1432-1912
    Keywords: Rat spinal cord in vitro ; Descending responses ; Ventral root ; Baclofen ; Catecholamines ; Excitatory amino acids ; 5-Hydroxytryptamine ; GABA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spinal cords were maintained in vitro and suction electrodes used to record activity in lumbar 4 or 5 ventral roots. Stimulation of the latero-ventral aspect of the thoracic cord elicited fast and slow responses on the same and on the opposite side of the cord. There were 5 distinct responses: ipsilaterally a short latency (d ISL), a polysynaptic and a slow response, and contralaterally a fast (d CON FAST) and a slow response. The largest amplitude component, d ISL, may arise from stimulation of propriospinal neurones; the other responses may arise from stimulation of descending pathways. The slow responses had half decay times of 13–15 s and required a high intensity stimulus to elicit a maximal response. All 5 responses were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione suggesting that kainate/AMPA receptors were involved in their generation. In addition, NMDA receptors were involved in generation of the slow responses. Potentiation of certain responses by the 5-HT2 antagonists, ketanserin, ritanserin and Lilly 53857, indicated that endogenous 5-HT was exerting a modulatory depression of these responses. In addition to eliciting the 5 responses, thoracic cord stimulation caused an inhibition of segmental reflexes evoked from the lumbar dorsal root. Exogenous 5-HT, 8-hydroxy-2-(di-n-propylamino) tetralin, 5-carboxamidotryptamine, dipropyl-5-carboxamidotryptamine and methysergide depressed all or some of the descending responses. Blockade of adrenoceptors using yohimbine, idazoxan, prazosin or propranolol had no unequivocal effect suggesting that the release of endogenous catecholamines was minimal. Clonidine was a potent depressant of the slow responses. Release of glycine and γ-aminobutyric acid (GABA) (acting upon GABAA receptors) by stimulation modulated d CON FAST and both slow responses. The large potentiation of slow responses by bicuculline suggests a considerable release of GABA. The absence of effect of 2-OH-saclofen did not suggest any activation of GABAB receptors by endogenous GABA, but both muscimol and baclofen had potent depressant actions on descending responses. It was concluded that glutamate was involved in the generation of these responses, they were modulated differentially by endogenous glycine, GABA and 5-HT, and application of muscimol, baclofen, clonidine, 5-HT and 5-HT receptor ligands modified the responses.
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    URL: http://dx.doi.org/10.1007/BF00166948
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    Role of serotonin receptors in the effect of sertraline on feeding behaviour (1993)
    Springer
    Psychopharmacology 110 (1993), S. 203-208 
    Details
    ISSN: 1432-2072
    Keywords: Sertraline ; Serotonin ; Catecholamines ; Food intake ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of sertraline, a serotonin (5-HT) uptake inhibitor, on 1 h food intake of food-deprived rats was studied in male rats treated intraperitoneally with 1 and 2.5 mg/kg metergoline, a 5-HT1 and 5-HT2 receptor antagonist, 0.5 mg/kg GR 38032F, a 5-HT3 receptor antagonist, or intracerebroventricularly with 6-hydroxy-dopamine to destroy catecholamine-containing neurons. The feeding-suppressant effect of 10 mg/kg sertraline was not significantly modified by any treatment. At 1 and 2.5 mg/kg metergoline did not significantly modify the reduction in total intake and meal size induced by sertraline in slightly-deprived rats whereas at 1 mg/kg the 5-HT receptor antagonist completely blocked the effect of 1.5 mg/kgd-fenfluramine, a 5-HT releaser and uptake inhibitor. In a runway test, metergoline at 1 but not 2.5 mg/kg significantly attenuated the effect of 10 mg/kg sertraline on starting speed in the first and second trial blocks. Both doses tended to attenuate the effect of sertraline on running speed but the interaction was not significant. The reduction in food intake induced by sertraline was antagonized only by 1 mg/kg metergoline in the last trial block. The bulk of these findings argues against an important role of 5-HT receptors in the effect of sertraline on feeding behaviour.
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    URL: http://dx.doi.org/10.1007/BF02246974
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    Mercuric chloride-induced alterations of levels of noradrenaline, dopamine, serotonin and acetylcholine esterase activity in different regions of rat brain during postnatal development (1993)
    Springer
    Archives of toxicology 67 (1993), S. 422-427 
    Details
    ISSN: 1432-0738
    Keywords: Mercuric chloride toxicity ; Developing brain ; Catecholamines ; Serotonin ; AChE ; Adaptive responses ; Operant conditioning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Wistar rats were fed mercuric chloride, 4 mg/kg body weight per day chronically from postnatal day 2 to 60 by gastric intubation. Mercury consumption was then discontinued until 170 days to allow time for recovery. Since mercury caused reduction in body weight, an underweight group was also included besides the normal saline group. Levels of noradrenaline (NA), dopamine (DA), 5-hydroxy-tryptamine (5-HT) and the activity of acetylcholine esterase (AChE) were assayed in various brain regions in different age groups. By 60 days of age, the mercury group showed elevations of NA levels in olfactory bulb (OB), visual cortex (VC) and brain stem (BS) but not in striatum-accumbens (SA) and hippocampus (HI). DA levels were also increased in OB, HI, VC and BS but not in SA. AChE activity was decreased in the mercury group only in HI and VC at 20 days of age. The Mercury group showed no behavioural abnormality outwardly; however, operant conditioning revealed a dificiency in performance. Nevertheless, all these changes disappeared after discontinuation of mercury intake. Thus the changes occurring in the brain at this level of oral mercuric chloride intake seem to reflect adaptive neural mechanisms rather than pathological damage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01977404
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    Tyrosine ameliorates a cold-induced delayed matching-to-sample performance decrement in rats (1993)
    Springer
    Psychopharmacology 112 (1993), S. 228-232 
    Details
    ISSN: 1432-2072
    Keywords: Cold stress ; Tyrosine ; Working memory ; Catecholamines ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Exposure to cold stress has been shown to impair short-term, or working, memory which may be related to a reduction in brain catecholamines. Administration of the catecholamine precursor tyrosine may alleviate a cold-stress-induced memory impairment by preventing a deficit in brain catecholamine levels. To test this hypothesis, eight rats performed a delayed matching-to-sample (DMTS) task at an ambient temperature of either 2°C (cold) or 22°C, following intraperitoneal administration of saline or tyrosine (50, 100 or 200 mg/kg). Rats administered saline prior to 22°C exposure demonstrated a characteristic delay gradient in which accuracy decreased as the delay interval between sample and comparison stimuli increased from 1 to 16 s. Consistent with previous research, and relative to 22°C exposure sessions, matching accuracy during 2°C exposure sessions was reduced, which is attributed to the effect of cold on short-term, or working, memory. In particular, during cold exposure sessions matching accuracy was significantly reduced at the longer delay intervals, relative to matching accuracy at 22°C. Additional analysis of cumulative matching errors within sessions showed that during exposure to cold, errors occurred at a constant rate throughout the session, indicating rats' performance was equally debilitated by the stressor over the entire session. During cold exposure sessions, the higher doses of 100 and 200 mg/kg tyrosine significantly improved overall matching accuracy relative to saline, but did not completely reverse the effect of cold exposure, as overall matching accuracy did not increase entirely to levels obtained at 22°C. A linear slope analysis of cumulative errors within cold sessions indicated that, relative to saline, the higher doses of tyrosine also significantly reduced errors, but did not reduce these errors to levels obtained during exposure to 22°C. It appears that supplemental tyrosine was effective in partially ameliorating the effects of cold stress on DMTS performance, possibly by preventing a cold-stress-induced reduction in brain catecholamine levels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244915
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    Myocardial adenosine stimulates release of cyclic adenosine monophosphate from capillary endothelial cells in guinea pig heart (1993)
    Springer
    Pflügers Archiv 423 (1993), S. 330-337 
    Details
    ISSN: 1432-2013
    Keywords: Coronary flow ; Hypoxia ; Adenylate cyclase ; Prostaglandin ; Catecholamines ; Adenosine triphosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Activation of coronary endothelial cell adenylate cyclase was studied in the isolated guinea pig heart by prelabelling endothelial adenine nucleotides using intracoronary infusion of [3H]-adenosine, and measuring the coronary efflux of [3H]-cyclic adenosine monophosphate (cAMP). Hypoxia (30 % O2) caused a 4-fold increase in coronary release of [3H]-cAMP, which was decreased by 63 % by infusion of the adenosine receptor antagonist, theophylline (50 μM). During normoxic control conditions, degrading adenosine to non-vasoactive inosine by intracoronary infusion of adenosine deaminase (1.7 U/ml) caused a 20 % decrease in the release of [3H]-cAMP. The effect of adenosine deaminase was reversed by a specific enzyme inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride. Coronary efflux of [3H]-cAMP during intracoronary infusion of 1 μM adenosine triphosphate (ATP), adenosine diphosphate or adenosine monophosphate (AMP) (plus adenosine deaminase 8 U/ml) was only 13 % of that due to 1 μM adenosine. Adenosine receptor blockers theophylline and CGS 15943A caused equivalent inhibition of the coronary vasodilator actions of adenosine and ATP. Intracoronary infusion of prostaglandin E1 and the β 2-adrenergic agonist procaterol caused parallel, dose-dependent increases in coronary conductance and the venous release of [3H] cAMP. It is concluded that (1) under both normoxic and hypoxic conditions, adenosine formed by the heart may activate endothelial cell adenylate cyclase via membrane adenosine receptors, (2) coronary receptors for adenosine and ATP share common ligand affinities but ATP receptors are not coupled to adenylate cyclase, and (3) other vasodilators known to activate endothelial adenylate cyclase in vitro cause parallel increases in coronary conductance and adenylate cyclase activity in the beating heart.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374413
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    Effects of clonidine, dihydralazine and splanchnic nerve stimulation on the release of neuropeptide Y, MET-enkephalin and catecholamines from dog adrenal medulla (1993)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 348 (1993), S. 379-384 
    Details
    ISSN: 1432-1912
    Keywords: Catecholamines ; Neuropeptides ; Adrenal medulla ; Clonidine ; Dihydralazine ; Splanchnic nerve stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Various neuropeptides are costored together with catecholamines in the adrenal medulla. The concurrent release (evaluated by adrenal vein plasma levels) of these neuropeptides [neuropeptide Y (NPY), met-enkephaline (ME)] and catecholamines [adrenaline (A) and noradrenaline (NA)] from the adrenal gland was examined in chloralose-anesthetized dogs after intravenous administration of clonidine (10 μg/kg) and dihydralazine (1 mg/kg). These results were compared to those obtained after the stimulation of the right splanchnic nerve at 1, 5 and 10 Hz frequencies. The increment in the release of catecholamines and neuropeptides was evaluated for dihydralazine and splanchnic nerve stimulation. Dihydralazine (at its maximal effect) induced a significant preferential increase in catecholamines (expressed as mean (SEM): NA: 17.3 (5.4) fold, A: 13.1 (2.6) fold) and ME (16.0 (7.1) fold) versus basal values. However, the significant increase in NPY-LI was only 2.0 (0.4) times the baseline. Splanchnic nerve stimulation induced a frequency-dependent increase in catecholamines and neuropeptides. When the stimulation frequency was increased from 1 Hz to 5 Hz, NA and A levels increased 17.9 (4.3) and 14.0 (2.2) fold, respectively and ME levels 14.1 (3.0) fold. By contrast, NPY-LI was increased only 2.3 (0.3) fold under the same conditions. Increasing the stimulation frequency from 5 Hz to 10 Hz resulted in similar elevations of NA, ME, and NPY-LI adrenal plasma levels (about 4 times) whereas A only increased twice. Clonidine decreased catecholamine and ME adrenal plasma levels (the maximal percent decrease when compared with control values was about 75%) whereas NPY adrenal plasma levels remained unchanged. In conclusion, the present data indicate that (i) both adrenal ME and NA always exhibit corelease in a parallel fashion which is not the case for NPY art; (ii) different populations of chromaffin vesicles could be preferentially mobilized according to different physiological and pharmacological patterns.
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    URL: http://dx.doi.org/10.1007/BF00171337
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    Organization of histamine-containing neurons in the brain of the crested newt, Triturus carnifex (1993)
    Springer
    Cell & tissue research 272 (1993), S. 147-154 
    Details
    ISSN: 1432-0878
    Keywords: Histamine ; Immunohistochemistry ; Brain, vertebrate ; Catecholamines ; Triturus carnifex (Urodela)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of immunoreactivity for histamine was studied in the brain of the urodele Triturus carnifex using the indirect immunofluorescence method. Histamine-immunoreactive cell bodies were localized in the caudal hypothalamus within the dorsolateral walls of the infundibular recesses. These immunoreactive cell bodies were pear-shaped, bipolar and frequently of the cerebrospinal-fluid-contacting type. Histaminergic nerve fibers were detected in almost all parts of the brain. Dense innervation was seen in the telencephalic medial pallium and ventral striatum, the neuropil of the preoptic area, the septum, the paraventricular organ, the posterior commissure, the caudal hypothalamus, the ventral and lateral mesencephalic tegmentum. Medium density innervation was observed in the lateral mesencephalic tegmentum and optic tectum. Poor innervation was present in the telencephalic dorsal pallium and in the central gray of the medulla oblongata. Few fibers occurred in the olfactory bulbs and in the telencephalic lateral pallium. Double immunofluorescence staining, using an antibody against tyrosine hydroxylase, showed that histamine-immunostained somata and those containing tyrosine-hydroxylase-like immunoreactivity were co-distributed in the tuberal hypothalamus. No co-occurrence of histamine-like and tyrosine hydroxylase-like immunostaining was seen in the same neuron. The pattern of histamine-immunoreactive neurons in the newt was similar to that described in other vertebrates. Our observations, carried out on the apparently simplified brain of the newt confirm that the basic histaminergic system is well conserved throughout vertebrates.
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    URL: http://dx.doi.org/10.1007/BF00323580
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    Distribution of tyrosine-hydroxylase-immunoreactive and dopamine-immunoreactive neurons in the central nervous system of the snail Helix pomatia (1993)
    Springer
    Cell & tissue research 274 (1993), S. 503-513 
    Details
    ISSN: 1432-0878
    Keywords: Nervous system, central ; Dopamine ; Tyrosine hydroxylase ; Catecholamines ; Immunocytochemistry ; Helix pomatia (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution and characterization of dopamine-containing neurons are described in the different ganglia of the central nervous system of Helix on the basis of the distribution of tyrosine hydroxylase immunoreactive (TH-ir) and dopamine immunoreactive (DA-ir) neurons. Both TH-ir and DA-ir cell bodies of small diameter (10–25 μm) can be observed in the buccal, cerebral and pedal ganglia, dominantly on their ventral surface, and concentrated in small groups close to the origin of the peripheral nerves. The viscero-parietal-pleural ganglion complex is free of immunoreactive cell bodies but contains a dense fiber system. The largest number of TH-ir and DA-ir neurons can be detected in the pedal, and cerebral ganglia. The average number of TH-ir and DA-ir neurons significantly differs but all the identifiable groups of TH-ir neurons also show DA-immunoreactivity. Therefore, we consider the TH-ir neurons in those groups as being DA-containing neurons. The amounts of DA in the different ganglia assayed by high performance liquid chromatography correspond to the distribution and number of TH-ir and DA-ir neurons in the different ganglia. The axon processes of the labeled small-diameter neurons send thin proximal branches toward the cell body layer but only rarely surround cell bodics, whereas distally they give off numerous branches in the neuropil and then leave the ganglion through the peripheral nerves. In the cerebral ganglia, the analysis of the TH-ir pathways indicates that the largest groups of labeled neurons send their processes through the peripheral nerves in a topographic order. These results furnish morphological evidence that DA-containing neurons of Helix pomatia have both central and peripheral roles in neuronal regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314547
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  • 46
    Electronic Resource
    Electronic Resource
    Autonomic modulation of insulin levels in foetal sheep (1993)
    Springer
    Clinical autonomic research 3 (1993), S. 331-338 
    Details
    ISSN: 1619-1560
    Keywords: Foetal insulin ; Glucose metabolism ; Autonomic nervous system ; Hypoxia ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The autonomic nervous system plays an important part in metabolic and circulatory adaptation of the foetus to changes in its intrauterine environment and after delivery. Foetal and neonatal glucose metabolism and insulin secretion are influenced by changes in humoral catecholamine levels as they may occur during asphyxia. To assess the role of neuronal and humoral sympathetic activity in foetal endocrine pancreatic regulation, chronically catheterized foetal sheep near term were chemically sympathectomized with 6-hydroxydopamine. Experiments were carried out in unanaesthetized foetal sheepin utero in the absence of uterine contractions. Insulin and glucose levels, blood gases, acid-base status and catecholamines were measured before, during and after a 2 min occlusion of uterine blood flow caused by mechanical constriction of the maternal aorta. Pancreatic blood flow was determined using radioactive labelled microspheres. During normoxaemia, insulin levels, pancreatic blood flow and glucose transport to the organ in sympathectomized foetuses were elevated compared with intact animals, whereas glucose concentrations did not show any significant differences. After the onset of asphyxia humoral catecholamine levels rose significantly in both groups. Insulin concentrations in the plasma of both intact and symphathectomized foetuses were no longer different indicating both indirect (blood flow and humoral catecholamine related) and direct (neurally mediated) sympathetic effects on pancreatic beta cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01827335
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  • 47
    Electronic Resource
    Electronic Resource
    The influence of aspirin on plasma and platelet catecholamine levels, and platelet function in normal man (1993)
    Springer
    Clinical autonomic research 3 (1993), S. 49-53 
    Details
    ISSN: 1619-1560
    Keywords: Aspirin ; Sympathoadrenal activity ; Catecholamines ; Thromboxane ; Platelets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of the study was to determine whether aspirin influences sympathoadrenal output in normal human subjects. Plasma and platelet adrenaline and noradrenaline levels were measured before and after chronic administration of oral aspirin (300 mg per day for 7 days). Catecholamine concentrations measured immediately following aspirin did not differ from control (pre-treatment) values. Platelet noradrenaline and plasma adrenaline levels were, however, significantly increased 2 weeks after cessation of treatment. Platelet TxB2 generation was significantly reduced following aspirin treatment indicating that platelet cyclooxygenase had been inhibited. Catecholamine concentrations did not correlate with TxB2 generation.In vitro platelet aggregation induced by ADP, adrenaline and collagen was reduced after aspirin providing additional confirmation of cyclooxygenase inhibition. However, thein vivo markers of platelet function, β-TG and PF4 were unaffected. These data do not provide convincing evidence for an action of aspirin on sympathoadrenal outflow, either directly or via a prostaglandin (thromboxane) mediated effect, although this does not exclude a later, delayed effect. There was no evidence for interactions between thromboxane, catecholamine levels in plasma and platelets, and platelet function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01819144
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  • 48
    Electronic Resource
    Electronic Resource
    Kinetics of heart rate and catecholamines during exercise in humans (1993)
    Springer
    European journal of applied physiology 66 (1993), S. 500-506 
    Details
    ISSN: 1439-6327
    Keywords: Exercise ; Heart transplantation ; Catecholamines ; Heart rate control ; Autonomic system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the role of factors other than the nervous system in heart rate (f c) control during exercise, the kinetics off c and plasma catecholamine concentrations were studied in ten heart transplant recipients during and after 10-min cycle ergometer exercise at 50 W. Thef c did not increase at the beginning of the exercise for about 60 s. Then in the eight subjects who completed the exercise it increased following an exponential kinetic with a mean time constant of 210 (SEM 22) s. The two other subjects were exhausted after 5 and 8 min of exercise during whichf c increased linearly. At the cessation of the exercise,f c remained unchanged for about 50 s and then decreased exponentially with a time constant which was unchanged from that at the beginning of exercise. In the group of eight subjects plasma noradrenaline concentration ([NA]) increased after 30 s to a mean value above resting of 547 (SEM 124) pg · ml−1, showing a tendency to a plateau, while adrenaline concentration ([A]) did not increase significantly. In the two subjects who became exhausted an almost linear increase in [NA] occurred up to about 1,300 pg · ml−1 coupled with a significant increase in [A]. During recovery an immediate decrease in [NA] was observed towards resting values. The values of thef c increase above resting levels determined at the time of blood collection were linearly related with [NA] increments both at the beginning and end of exercise with a similar slope, i.e. about 2.5 beats · min−1 per 100 pg · ml−1 of [NA] change. These findings would seem to suggest that in the absence of heart innervation the increase inf c depends on plasma [NA].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634299
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  • 49
    Electronic Resource
    Electronic Resource
    Time of day effects on sympathoadrenal and pressor reactivity to exercise in healthy men (1993)
    Springer
    European journal of applied physiology 67 (1993), S. 159-163 
    Details
    ISSN: 1439-6327
    Keywords: Time of day ; Catecholamines ; Blood pressure ; Exercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To investigate the influence of time of day on sympathoadrenal and pressor reactivity during exercise, eight trained men [age, mean (SD), 24 (0.5) years; maximal oxygen uptake ( $$\dot VO_{2max} $$ ), 4.7 l·min−1] performed bouts of static (ST) and dynamic (DYN) exercise at 0600–0800 hours (AM) and at 1600–1800 hours (PM). The ST protocol utilized a two-leg isometric contraction at 30% maximum voluntary contraction until failure, and was monitored by a strain gauge interfaced from a leg extension apparatus to a computer. Heart rate (fc) and blood pressure ( $$\bar P_a $$ ) responses were recorded at rest, after 1 and 2 min of exercise, and at failure. Epinephrine (EPI) and norepinephrine (NE) levels were recorded before exercise, and after 2 min of exercise. The DYN exercise protocol involved stationary. cycling for consecutive 6-min periods at 60% and 80% $$\dot VO_{2max} $$ . fc, $$\bar P_a $$ , EPI, and NE were recorded before exercise and at each workload. No differences were observed in preexercise or exercise fc under any condition. Preexercise $$\bar P_a $$ did not differ under any condition. The $$\bar P_a $$ response to DYN was significantly higher at 80% $$\dot VO_{2max} $$ during PM only. $$\bar P_a $$ was significantly higher in ST-PM at 1 min, 2 min, and failure. Elevations in both systolic and diastolic P a contributed to this difference. Preexercise EPI-ST-AM was significantly elevated vs PM, but no other preexercise data were significantly different. Absolute exercise levels were significantly higher for EPIST-PM vs AM only, but the percentage change from baseline was significantly (P〈0.01) higher in ST-PM for EPI (+231% PM vs + 32% AM) and NE (+352% PM vs +216% AM). The EPI and NE responses to DYN exercise tended to be higher in AM, but were not significantly different. These data support a time of day pattern in sympathoadrenal and pressor reactivity to exercise that is dependent on the type of activity involved but independent of baseline patterns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376660
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  • 50
    Electronic Resource
    Electronic Resource
    Snoring, sympathetic activity and cardiovascular risk factors in a 70 year old population (1993)
    Springer
    European journal of epidemiology 9 (1993), S. 477-482 
    Details
    ISSN: 1573-7284
    Keywords: Snores ; Alcohol ; Smoking ; Catecholamines ; Lipids ; Metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to describe the relation between snoring, cardiovascular risk factors, metabolic factors and sympathetitic activity, 804 70-year-old males and females were classified according to snoring habits and life-style factors (alcohol and tobacco consumption), blood pressure, body mass index (BMI), plasma lipids (triglycerides, cholesterol, high density lipoprotein), plasma catecholamines (epinephrine, norepinephrine), fasting blood glucose and glucose tolerance test (1 gram glucose per kg body weight given and blood glucose was measured 1 and 2 hours thereafter) were evaluated in all participants. Self-reported snoring was associated with gender (males showed higher prevalence than females, p 〈 0.05), alcohol consumption (p 〈 0.01), BMI (p 〈 0.001), systolic (p 〈 0.01) and diastolic (p 〈 0.05) blood pressure, glucose tolerance test (p 〈 0.01), plasma norepinephrine (p 〈 0.05) and partly with tobacco consumption (p = 0.08). No associations were found between snoring and fasting glucose, plasma lipids, plasma epinephrine or in the use of antihypertensive medication. In multivariate analysis, with forced entry of gender, BMI, physical activity, alcohol and tobacco consumption, the relation between snoring and blood pressure ceased; only systolic blood pressure was associated with snoring (p 〈 0.05). Snoring was still associated with plasma norepinephrine (p 〈 0.001) and abnormal glucose tolerance (p 〈 0.001). We conclude that, in a 70-year-old population, snoring is associated with gender, BMI and alcohol consumption. Snores showed higher plasma norepinephrine and abnormal glucose tolerance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209524
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  • 51
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    Electronic Resource
    The effect of exogenous catecholamines on the ventilatory and cardiac responses of normoxic and hyperoxic rainbow trout, Oncorhynchus mykiss (1993)
    Springer
    Journal of comparative physiology 163 (1993), S. 138-146 
    Details
    ISSN: 1432-136X
    Keywords: Catecholamines ; Ventilation ; Normoxia ; Hyperoxia ; Trout, Oncorhynchus mykiss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Ventilation frequency, opercular pressure amplitude, heart rate, dorsal aortic pressure, arterial pH, arterial O2 tension, and plasma catecholamine levels were recorded in rainbow trout, Oncorhynchus mykiss, during normoxia (19.7 kPa, 148 mmHg) or hyperoxia (51.2 kPa, 384 mmHg) after injection of various concentrations of catecholamines. In normoxic fish, adrenaline injection resulted in a depression of arterial O2 tension, hypoventilation due to a drop in ventilation frequency, and a drop in heart rate, while dorsal aortic pressure increased. Noradrenaline depressed ventilation frequency, but opercular pressure amplitude increased to a far greater extent, and dorsal aortic pressure increased. During hyperoxia, adrenaline injection lowered ventilation frequency, opercular amplitude and heart rate, but dorsal aortic pressure increased. The stimulatory effects of noradrenaline on ventilation were abolished during hyperoxia, but the cardiac responses were similar to those seen during normoxia. These results indicate that catecholamines can modify the ventilatory output from the respiratory centre, and modification of ventilation frequency can occur independently of opercular pressure amplitude.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00263599
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  • 52
    Electronic Resource
    Electronic Resource
    Evidence for multiple adrenoceptor sites in rainbow trout vasculature (1993)
    Springer
    Journal of comparative physiology 163 (1993), S. 470-476 
    Details
    ISSN: 1432-136X
    Keywords: Blood pressure ; Sympathetic nervous system ; Catecholamines ; Receptors ; Trout, Oncorhynchus mykiss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The importance of neuronal and lumenal vascular adrenoceptors in the regulation of vascular reactivity was examined in rainbow trout (Oncorhynchus mykiss), in vivo and in vitro. In vivo, ganglionic blockade with hexamethonium or α-adrenoceptor blockade, with either phentolamine or prazosin, produced similar (7 mmHg) decreases in dorsal aortic blood pressure. The drop in dorsal aortic pressure produced by phentolamine or prazosin was due to reduced systemic vascular resistance. Neither the α-adrenoceptor antagonist, phenoxybenzamine nor chemical sympathectomy with 6-hydroxy-dopamine affected dorsal aortic pressure. However, after chemical sympathectomy, phenoxybenzamine lowered dorsal aortic pressure to levels similar to that produced by either phentolamine or prazosin. Plasma epinephrine and norepinephrine concentrations increased four- and twofold, respectively, in sympathectomized fish. Sympathectomy also produced a leftward shift in the epinephrine dose/response curve of the in vitro perfused splanchnic vasculature, placing the effective catecholamine concentration well within the in vivo plasma levels. These results indicate that following chemical sympathectomy arterial blood pressure is stabilized by circulating catecholamines through the combined effect of increased plasma catecholamine concentrations and increased sensitivity of vascular adrenoceptors. Phenoxybenzamine is incapable of blocking neuronal vascular adrenoceptors but is a potent antagonist of the up-regulated adrenoceptors, suggesting that the latter are localized on the lumenal side of the vessel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00346931
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  • 53
    Electronic Resource
    Electronic Resource
    Extension of the application of the thermal in-situ reaction on NH2 layers to the detection of catecholamines in biological materials (1993)
    Springer
    Chromatographia 37 (1993), S. 133-143 
    Details
    ISSN: 1612-1112
    Keywords: Thin-layer chromatography ; NH2-silica gel ; Catecholamines ; Urine samples
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This article describes a thin-layer chromatographic method for the determination of catecholamines in human urine. Chromatographic separation on NH2-modified silica gel layers is followed by in-situ visualization brought about by heating the plate. The use of this derivatization technique for other urine components, such as creatine, creatinine, uric acid and glucose, is also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02275850
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  • 54
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    Electronic Resource
    Simultaneous assay of platelet and plasma catecholamines by HPLC with coulometric detection (1993)
    Springer
    Chromatographia 36 (1993), S. 164-166 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Platelet ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Platelets and monoaminergic neurons share many morphological, biochemical, and pharmacological properties. In addition to its similarities to serotonergic nerve endings, the platelet has also been considered a good model for the study of the noradrenergic function, since it can selectively take up, store, and release norepinephrine (NE). In this study platelet and plasma levels of free catecholamines (CA) in 20 healthy subjects have been determined by HPLC with a reversed phase (C18) ionpairing system equipped with a coulometric detector. Direct correlation was observed between platelet and plasma levels of NE. A positive correlation was also found between the age of the sujects and both platelet and plasma NE levels. While showing that the peripheral noradrenergic hyperactivity of the elderly is also reflected in platelet NE content, this study also demonstrates that simultaneous assay of platelet and plasma CAs can be a useful tool for an integrated and more complete evaluation of sympathetic nervous system activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02263855
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  • 55
    Electronic Resource
    Electronic Resource
    Changes in coagulation and fibrinolytic activity associated with tracheal intubation (1992)
    Springer
    Journal of anesthesia 6 (1992), S. 80-84 
    Details
    ISSN: 1438-8359
    Keywords: Tracheal intubation ; Catecholamines ; Coagulation and fibrinolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study was carried out to clarify the effect of tracheal intubation on the coagulation and fibrinolytic system. It was performed on 20 patients (ASA class 1–2) undergoing elective surgery. Before and after tracheal intubation, hemodynamics, ACTH, cortisol, catecholamines, and several coagulation and fibrinolytic factors were measured. Tracheal intubation was accompanied by significant increases in the blood pressure, heart rate, and norepinephrine level. No changes were observed in fibrinopetide A, fibrinopeptide BΒ15–42, tissue plasminogen activator antigen, plasminogen, fibrinogen, and Α2 plasmin inhibitor. Patients exposed to long intubation time (≫20 seconds) were found to have a significantly higher level of fibrinopeptide A than patients with short tracheal intubation time (≦20 seconds) (P ≪ 0.05). It therefore can be concluded that the increase in norepinephrine and changes in the hemodynamics following tracheal intubation have no impact on the coagulation and fibrinolytic activity. Also, if the duration of intubation is prolonged, thrombin activity may be promoted. (Gando S, Tedo I, Kubota M, et al.: changes in coagulation and fibrinolytic activity associated with tracheal intubation. J Anesth 6: 80–84, 1994)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s0054020060080
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  • 56
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    Electronic Resource
    Inhibitory actions of dopamine on Limulus visceral muscle involve a cyclic AMP-dependent mechanism (1992)
    Springer
    Journal of comparative physiology 170 (1992), S. 787-795 
    Details
    ISSN: 1432-1351
    Keywords: Catecholamines ; cAMP ; Midgut
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The catecholamines dopamine, epinephrine and norepinephrine were detected in alumina extracts of Limulus midgut tissue using high performance liquid chromatography with electrochemical detection. Moderate levels of norepinephrine (28.2±2.1 ng/g) and dopamine (24.0±5.2 ng/g) were detected in the midgut, while epinephrine levels (7.4±0.9 ng/g) were less. Catecholamines were present in all regions along the longitudinal axis of the midgut, and norepinephrine and dopamine levels were highest in posterior regions. 2. Catecholamines decreased muscle tonus and inhibited spontaneous contractions of the Limulus midgut. Dopamine typically decreased spontaneous midgut activity at doses of 10−8 M or greater, and produced inhibitory actions on all regions of the Limulus midgut. In some preparations epinephrine and norepinephrine elicited a secondary rhythmicity. The actions of dopamine opposed the excitatory effects produced by either proctolin or octopamine. 3. Catecholamines significantly elevated levels of cyclic AMP in Limulus midgut muscle rings. Dopamine (10−5 M) increased cyclic AMP with a time course consistent with its physiological effects. Forskolin and several methyl xanthines increased Limulus midgut cyclic AMP levels and mimicked the inhibitory effects of dopamine on the isolated midgut preparation. Cyclic nucleotide analogues also produced dopamine-like effects on the isolated midgut preparation. Inhibition of cyclic nucleotide phosphodiesterase prior to addition of dopamine enhanced the effect of this amine to decrease baseline muscle tension. 4. The inhibitory effects of 10−5 M dopamine on the midgut persisted in solutions of zero sodium and in the presence of tetrodotoxin. Zero calcium solutions gradually reduced spontaneous midgut activity and the effects of dopamine. Calcium channel blockers did not prohibit dopamine-induced relaxation. These findings suggest that direct, inhibitory actions of dopamine on the Limulus midgut are mediated by increased levels of cyclic AMP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00198989
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  • 57
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    Electronic Resource
    Mechanisms regulating renal sodium excretion during development (1992)
    Springer
    Pediatric nephrology 6 (1992), S. 205-213 
    Details
    ISSN: 1432-198X
    Keywords: Newborn ; Fetus ; Sodium ; Atrial natriuretic factor ; Catecholamines ; Renal nerves ; Aldosterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The present review focuses on the ontogeny of mechanisms involved in renal sodium excretion during renal maturation. The effect of birth on renal excretion of sodium and the role played by the different tubular segments in the regulation of sodium excretion during maturation are discussed. The influence of circulating catecholamines and renal sympathetic innervation in regulating sodium excretion during renal development is reviewed. The effects of aldosterone, atrial natriuretic factor, and prostaglandins on sodium regulation during renal maturation are discussed. Special emphasis is given to the potential role of glucocorticoids in modulating sodium excretion early in life.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00866320
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  • 58
    Electronic Resource
    Electronic Resource
    Critical care in uraemic children (1992)
    Springer
    Pediatric nephrology 6 (1992), S. 88-95 
    Details
    ISSN: 1432-198X
    Keywords: Chronic kidney failure ; Respiratory therapy ; Dialysis ; Blood coagulation disorders ; Intracranial pressure ; Catecholamines ; Bacterial infections
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The special problems posed by renal disease have to be considered when a uraemic child requires intensive care. This report gives an overview on the problems of dialysis treatment, circulatory support, infectious complications, coagulation disorders and increased intracranial pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00856850
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  • 59
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    Electronic Resource
    Plasma protein binding of catecholamines, prazosin and propranolol in diabetes mellitus (1992)
    Springer
    European journal of clinical pharmacology 43 (1992), S. 265-268 
    Details
    ISSN: 1432-1041
    Keywords: Diabetes mellitus ; Drug protein binding ; Catecholamines ; adrenoceptor blockers ; prazosin ; propranolol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In the present study equilibrium dialysis has been used to determine the degree of protein binding of the catecholamines adrenaline and noradrenalin and the adrenergic receptor blockers, prazosin and propranolol in diabetics. The binding of the catecholamines in plasma from Type I and II diabetic patients was not significantly different from that of healthy subjects. The ratio of the bound and free catecholamine concentrations was correlated with the level of albumin (HSA). Significantly reduced protein binding of prazosin was observed in Type I and II diabetic subjects compared to healthy volunteers. The binding of propranolol was significantly reduced in Type I patients. The ratios between the bound and unbound concentrations of prazosin and propranolol were significantly correlated with the levels of a,-acid glycoprotein (AAG). The results suggest that non-enzymatic glycosylation of plasma proteins may increase the unbound fraction of the adrenergic blockers prazosin and propranolol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02333020
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  • 60
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    Differential short-term desensitization to vasopressin, isoproterenol, glucagon, parathyroid hormone and calcitonin in the thick ascending limb of rat kidney (1992)
    Springer
    Pflügers Archiv 420 (1992), S. 16-22 
    Details
    ISSN: 1432-2013
    Keywords: Adenosine 3′,5′-(cyclic)monophosphate ; Hormone receptors ; Microdissection ; Nephron segments ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Short-term desensitization to hormone-induced cAMP accumulation was investigated in the medullary (MTAL) and the cortical (CTAL) thick ascending limbs of Henle's loop isolated by microdissection from the rat kidney. The following agonists were studied: vasopressin, glucagon and human calcitonin in the MTAL, and vasopressin, glucagon, human calcitonin, parathyroid hormone (PTH) and the β-adrenergic agonist isoproterenol in the CTAL. Isolated tubules were preincubated in vitro for 60 min in the presence or absence of a maximal concentration of one of the five agonists (vasopressin 10 nM, glucagon 10 nM, calcitonin 100 nM, PTH 10 nM, isoproterenol 1 μM). Desensitization induced by each agent to its own action was then quantified by measuring the amount of cAMP accumulating in the presence of the phosphodiesterase inhibitor isobutylmethylxanthine and the same agonist concentration as that used during preincubation. In the MTAL, as previously reported, preincubation with vasopressin led to a marked (80%–85%) desensitization to this hormone. A significant hormone self-induced desensitization of about 45% was also obtained with glucagon, but not with calcitonin. In the CTAL, the following order of potency to elicit desensitization was observed: vasopressin (80%) 〉 isoproterenol (50%) 〉 glucagon (30%) 〉 PTH (20%, NS) 〉 calcitonin (10%, NS). Thus, the magnitude of desensitization varied greatly from one hormone to another, but for a given hormone, was of roughly similar extent in both MTAL and CTAL. The strikingly different patterns of desensitization to vasopressin and calcitonin were confirmed by kinetics analysis of cAMP accumulation, which revealed that the action of the former hormone was much more rapidly blunted than that of the latter. It is concluded that vasopressin, isoproterenol and glucagon are all able to induce short-term desensitization in the thick ascending limb, although the extent of the process is specific for each agonist. The different degrees of desensitization to unrelated hormones may indicate variable capacities of the corresponding receptors for undergoing short-term desensitization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378636
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  • 61
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    Biochemical effects of high single doses of moclobemide in man: correlation with plasma concentrations (1992)
    Springer
    Psychopharmacology 106 (1992), S. S46 
    Details
    ISSN: 1432-2072
    Keywords: Moclobemide ; Catecholamines ; Concentration-effect relationship
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of high single doses of moclobemide (300, 450 and 600 mg given at the end of a standardized meal) on plasma levels of several catecholamines and their deaminated metabolites, and on plasma levels of pituitary hormones were determined in eight healthy young male volunteers in a randomised, double-blind, placebo-controlled study. Assessment of the i.v. tyramine potentiation and determination of the plasma levels of moclobemide were also performed. The tyramine sensitivity factor at 2 h after dosing was about 2.1, with no significant differences between the doses used. The inhibitory activity of moclobemide on MAO-A was reflected in significant reductions of plasma concentrations of DHPG and 5-HIAA. No clear differences were detected between the moclobemide doses. Prolactin plasma concentrations were only slightly increased after the two higher doses. The plasma concentrations of moclobemide were very much in agreement with those found in previous studies under similar experimental conditions. Thus, single oral doses of 300, 450 and 600 mg moclobemide demonstrated marked inhibition of MAO-A activity, whereas a single dose of 300 mg induced a near-maximum effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02246235
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  • 62
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    Vascular uptake of catecholamines in perfused lungs of the rat occurs by the same process as Uptake1 in noradrenergic neurones (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 319-326 
    Details
    ISSN: 1432-1912
    Keywords: Rat lungs ; Catecholamines ; Uptake1 ; Pulmonary endothelial cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aim of the study was to determine whether the uptake process for catecholamines in rat lungs is Uptake1, Uptake2 or a distinct process with some properties of both Uptake1 and Uptake2. The initial rate of uptake of noradrenaline was measured in isolated lungs of rats perfused with 2 nmol/l 3H-(−)-noradrenaline for 2 min with monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) inhibited, in the absence or presence of drugs that are substrates or inhibitors of Uptake1 or Uptake2 or of alterations in the ionic composition of the Krebs solution. The rank order of the IC50 values for inhibition of uptake of noradrenaline in the lungs by drugs that are substrates or inhibitors of Uptake1 or Uptake2 is compatible with the conclusion that uptake of catecholamines in rat lungs occurs by Uptake2, and not by a process with the properties of Uptake2. Additional evidence was provided by the marked inhibition of uptake in the lungs when the Na+ concentration in the Krebs solution was decreased from 143 to 25 mmol/l and by the lack of inhibition when the K+ concentration was increased from 5.9 mmol/l to either 10.9 or 20.9 mmol/1. Further experiments were included in the study to obtain data additional to histological evidence (Hughes et al. 1969; Nicholas et al. 1974) regarding the site of Uptake1 in rat lungs. Pretreatment of rats with either 6-hydroxydopamine (to destroy noradrenergic neurones) or reserpine (to inhibit synaptic vesicle uptake) had no effect on the deamination or accumulation of noradrenaline in lungs perfused with 3H-noradrenaline (COMT inhibited). In a further series of experiments, efflux of noradrenaline from rat lungs, after loading with 3H-noradrenaline (MAO and COMT inhibited), could be described by a single compartment with a half-time for efflux of 42 min and with no “bound fraction”. These results provide further evidence that no significant uptake of noradrenaline in the lungs occurs into noradrenergic neurones and are compatible with histological evidence that the endothelial cells of the lung microvasculature are the site of noradrenaline uptake. The study has shown that the uptake of catecholamines in the lungs, at least in the rat, occurs by Uptake1, and hence the pulmonary endothelial cells are a nonneuronal site where catecholamine transport occurs by Uptake1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00168693
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    Is neuropeptide Y co-released with catecholamines in experimental arterial hypertension following sinoaortic denervation? (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 431-436 
    Details
    ISSN: 1432-1912
    Keywords: Catecholamines ; NPY ; Conscious dogs ; Sinoaortic denervation ; Yohimbine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The release of catecholamines and their co-neurotransmitter neuropeptide Y (NPY) was investigated in conscious dogs with neurogenic arterial hypertension elicited by sinoaortic denervation. One month after denervation, an elevation of catecholamine levels (measured by HPLC) without elevation of NPY-like immunoreactivity (NPY-LI) levels in plasma (evaluated by RIA) has been found. This dissociation could be explained by 1) a transient release of NPY during the first weeks after surgery, 2) a depletion of neuronal NPY due to the permanent sympathetic stimulation, or 3) an insufficient increase in sympathetic tone. To test these hypotheses, we investigated the time courses of catecholamine and NPY-LI levels in arterial plasma during the first five weeks after sinoaortic denervation and responses to yohimbine (an alpha2 antagonist which enhances transmitter release). Resting NPY-LI levels in plasma remained normal during the first five weeks after sinoaortic denervation. In normal dogs, a high dose of yohimbine (0.5 mg/kg i. v.) elevated both catecholamine (6-fold) and NPY-LI levels (1.5-fold), whereas a lower dose (0.05 mg/kg i. v.) induced a two fold elevation of catecholamine levels without changing NPY-LI concentrations. In sinoaortically denervated dogs, yohimbine elicited elevation of both catecholamines and NPY-LI whatever the dose used. Thus, neurogenic arterial hypertension in dogs seems to involve catecholamines but not NPY. Moreover, the present work suggests that a high level of sympathetic stimulation is required for a co-release of catecholamines and NPY.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00176621
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    Dopamine and adrenaline, but not isoprenaline, are substrates for uptake and metabolism in isolated perfused lungs of rats (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 346 (1992), S. 20-26 
    Details
    ISSN: 1432-1912
    Keywords: Rat lungs ; Catecholamines ; Uptake1 ; Monoamine oxidase ; Catechol-O-methyltransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The uptake and subsequent metabolism by catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO) of dopamine, adrenaline, isoprenaline and noradrenaline in isolated perfused lungs of rats has been examined. In lung preparations in which COMT and MAO were inhibited, the uptake of 3H-labelled dopamine, (−)-adrenaline and (−)-noradrenaline, but not (±)-isoprenaline, was reduced by cocaine (10 or 100 μmol/l) The rank order of the Km values of the amines that were substrates for uptake in the lungs were: dopamine (0.246 μmol/l) 〈 noradrenaline (0.967 μmol/l) 〈 adrenaline (3.32 μmol/l). These results are consistent with transport of catecholamines in rat lungs by Uptake1. In lung preparations with COMT and MAO intact, dopamine and noradrenaline were removed from the circulation (50% and 32%, respectively) and mainly metabolized. There was very little (3.0%) removal of isoprenaline by the lungs and adrenaline was not included in this part of the study. In lung preparations in which only MAO was inhibited, the rank order of COMT activity for O-methylation of the amines was dopamine ≪ noradrenaline ≥ adrenaline (kCOMT values: 4.98 min−1, 0.357 min−1, and 0.234 min−1, respectively). If dopamine or adrenaline are perfused through the pulmonary circulation in isolated lungs of the rat, they are taken up and then metabolized by COMT and MAO, as also occurs for noradrenaline. Isoprenaline is not a substrate for uptake in the lungs. There was less uptake of adrenaline than noradrenaline, indicating that uptake and metabolism in the lungs may not be a significant removal process for adrenaline in the circulation of rats in vivo. The more marked uptake of dopamine (than of noradrenaline) indicates that uptake and metabolism by the lungs, at least in the rat, may play an important role in the removal of dopamine from the circulation in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167565
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    Catecholaminergic cells and fibers in the brain of the lizard Anolis carolinensis identified by traditional as well as whole-mount immunohistochemistry (1992)
    Springer
    Cell & tissue research 270 (1992), S. 319-337 
    Details
    ISSN: 1432-0878
    Keywords: Brain, vertebrate ; Catecholamines ; Tyrosine hydroxylase ; Immunohistochemistry ; Anolis carolinensis (Lacertilia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using traditional as well as whole-mount immunohistochemistry, we described the location of tyrosine hydroxylase-and dopamine beta hydroxylase-positive cells and fibers in the brain of the lizard Anolis carolinensis. Major catecholaminergic cell groups were in the ependyma in certain ventricular regions, alous coeruleus, anterior hypothalamic and lateral hypothalamic areas, and in the mesencephalic tegmental region, locus coeruleus, nucleus of the solitary tract, vagal motor nucleus, and rhombencephalic reticular formation. Major catecholaminergic fibers, tracts and varicosities included tuberohypophysial, mesolimbic, nigrostriatal, isthmocortical, medullohypothalamic, and coeruleospinal systems. Although the catecholaminergic systems in A. carolinensis are similar to those in the brains of other lizards studied, there are a few species differences. Our information about A. carolinensis will be used to help localize the hypothalamic asymmetry in catecholamine metabolism previously described in this lizard.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328017
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    Influence of post-exercise activity on plasma catecholamines, blood pressure and heart rate in normal subjects (1992)
    Springer
    Clinical autonomic research 2 (1992), S. 89-97 
    Details
    ISSN: 1619-1560
    Keywords: Exercise recovery ; Noradrenaline ; Adrenaline ; Catecholamines ; Heart rate ; Blood pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this study was to evaluate whether or not the type of activity performed during recovery might influence the magnitude of catecholamine outflow following exercise. Six active, male volunteers between 40–52 years recovered from strenuous treadmill exercise in three different ways; standing, supine rest and walking (2 mph, 0% grade). Measurements of noradrenaline (NA), adrenaline (A), heart rate and blood pressure were made at rest, peak exercise, and at 30 s intervals through 5-min of recovery. Peak exercise NA concentrations were approximately 1000% above those recorded as rest. Early recovery was marked by a continued increase in NA from peak exercise concentrations (4614 ± 548vs. 3264 ± 485 pg/ml) which did not return to peak exercise levels until approximately 90 s of recovery. Adrenaline responses followed similar trends; however, the changes were not as sizable. Heart rate and diastolic blood pressure were significantly affected by the post-exercise condition; supine recovery produced significantly lower mean heart rates and mean diastolic blood pressures in comparison to standing or continued walking recovery conditions. Thus, these data indicate no specific recovery strategy will stem the rise in exercise-induced plasma catecholamines. Clinically, a strategy of continued walking, or better, supine recovery will best meet special clinical requirements, as well as limit the magnitude of the peak catecholamine increases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01819663
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    Glucose and free fatty acid utilization during prolonged exercise in prepubertal boys in relation to catecholamine responses (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 66-72 
    Details
    ISSN: 1439-6327
    Keywords: Children ; Exercise ; Catecholamines ; Glucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ten prepubertal boys performed 60-min cycle exercise at about 60% of their maximal oxygen uptake as previously measured. To measure packed cell volume, plasma glucose, free fatty acids (FFA), glycerol and catecholamines, blood samples were drawn at rest using a heparinized cathether and at the 15th, 30th and 60th min of the exercise and after 30 min of recovery. At rest, the blood glucose concentrations were at the lowest values for normal. Exercise induced a small decrease of blood glucose which was combined with an abrupt increase of the noradrenaline concentration during the first 15 min. The FFA and glycerol concentrations increased throughout the exercise linearly with that of adrenaline. Compared to adults, the FFA uptake expressed per minute and per litre of oxygen uptake was greater in children. These results suggested that it is difficult for children to maintain a constant blood glucose concentration and that prolonged exercise provided a real stimulus to hypoglycaemia. An immediate and large increase in noradrenaline concentration during exercise and a greater utilization of FFA was probably used by children to prevent hypoglycaemia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01466276
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    Mobilization of circulating leucocyte and lymphocyte subpopulations during and after short, anaerobic exercise (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 164-170 
    Details
    ISSN: 1439-6327
    Keywords: Lymphocyte subpopulations ; Natural killer cells ; Memory cells ; Sequential mobilization ; Catecholamines ; Anaerobic exercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A group of 11 healthy athletes [age, 27.4 (SD 6.7) years; body mass, 75.3 (SD 9.2) kg; height, 182 (SD 8) cm; maximal oxygen uptake, 58.0 (SD 9.9) ml · kg−1 · min−1] conducted maximal exercise of 60-s duration on a cycle ergometer [mean exercise intensity, 520 (SD 72) W; maximal lactate concentration, 12.26 (SD 1.35) mmol · l−1]. Adrenaline and noradrenaline, and leucocyte subpopulations were measured flow cytometrically at rest, after 5-min warming up at 50% of each individual's anaerobic threshold (followed by 5-min rest), immediately after (0 min), 15 min, 30 min, and 1, 2, 4 and 24 h after exercise. Granulocytes showed two increases, the first at 15 min and, after return to pre-exercise values, the second more than 2 h after exercise. Eosinophils also increased at 15 min but decreased below pre-exercise values 2 h after exercise. Total lymphocytes and monocytes had their maximal increases at 0 min. Out of all lymphocyte subpopulations CD3−CD16/CD56+- and CD8S+ CD45RO−-cells increased most and had their maximal cell counts at 0 min. The CD3+-, CD4+CD45RO+-, CD8+ CD45RO+-, and CD19+- increased at 0 min, but had their maximum at 15 min. During the hours after exercise CD3− CD16/CD56+-, CD3+CD16/CD56+-, CD8+CD45RO+- and CD8+ CD45RO−-cells were responsible for the lymphocytopenia. The CD3+- and CD3− CD16/CD56+-cells were lower 24h after exercise than before exercise. Adrenaline and noradrenaline increased during exercise. In conclusion, short anaerobic exercise led to a sequential mobilization of leucocyte subpopulations. The rapid increase of natural killer cells and monocytes may have been due to increased blood flow and catecholamine concentrations. We interpreted from these results that those cells forming the first line of defence can be mobilized faster and disappear out of circulation more rapidly than all other cell populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705075
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    Changes in the leucocyte count during and after brief intense exercise (1992)
    Springer
    European journal of applied physiology 64 (1992), S. 518-522 
    Details
    ISSN: 1439-6327
    Keywords: Leucocytosis ; Catecholamines ; Lactate ; Lymphocytes ; Nuutrophils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twelve healthy male volunteers exercised at 200 W on a cycle ergometer for 8 min or until exhausted, if sooner. Retrospectively, subjects fell into two groups. During the last minute of exercise at 200 W, those in group 1 (n = 5) had a mean respiratory exchange ratio (R) of 1.06 (SD 0.01) and were working at a mean of 79% (SD 4%) of their maximum oxygen consumption ( $$\dot VO_{2\max } $$ ) as measured in a separate incremental load test. For subjects in group 2 (n =7),R was 1.31 (SD 0.08) and their $$\dot VO_2 $$ was maximal (mean 101%. SD 3% . Plasma lactate, and adrenaline concentrations rose to higher levels during exercise in subjects in group 2 than in those in group 1. At the finish of exercise, the leucocyte count and the plasma lactate concentration immediately began to fall in subjects in group 1 whereas in group 2 subjects both rose for several minutes before falling. Plasma catecholamine concentrations fell rapidly in both groups during recovery.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00843761
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    The effect of a high carbohydrate diet on running performance during a 30-km treadmill time trial (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 18-24 
    Details
    ISSN: 1439-6327
    Keywords: Diet ; Endurance ; Carbohydrate metabolism ; Catecholamines ; Running
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The purpose of the present study was to examine the influence of a high carbohydrate diet on running performances during a 30-km treadmill time trial. Eighteen runners (12 men and 6 women) took part in this study and completed a 30-km time trial on a level treadmill without modifying their food intake (trial 1). The runners were then randomly assigned to a control or a carbohydrate (CHO) group. The CHO group supplemented their normal diets with additional carbohydrate in the form of confectionery products during the 7 days before trial 2; the control group matched the increased energy intake of the CHO group by consuming additional fat and protein. The mean (SEM) carbohydrate intake of both groups was 334 (22) g before trial 1, after which the CHO group consumed 566 (29) g · day−1 for the first 3 days and 452 (26) g · day−1 for the remaining 4 days of recovery. Although there was no overall difference between the performance times for the two groups during trial 2, the CHO group ran faster during the last 5 km of trial 2 than during trial−1 [3.64 (0.24) m · s−1 vs 3.44 (0.26) m · s−1 P 〈 0.05] . Furthermore, the 6 men in the CHO group ran the 30 km faster after carbohydrate loading [131.0 (5.4) min vs 127.4 (4.9) min;P 〈 0.05], whereas there was no such improvement in times of the men in the control group. Blood glucose concentrations of both groups decreased below pre-exercise values during trial−1 (P 〈 0.001), but only the control group had a decrease in blood glucose concentrations during trial 2 (P 〈 0.001). There were no differences between the concentrations of plasma catecholamines of the control group during the two trials. However, the adrenaline concentrations of the CHO group were lower (P 〈 0.05) during trial 2 than during trial 1, even though they ran faster during trial 2. These results confirm that dietary carbohydrate loading improves endurance performance during prolonged running and that confectionery can be used as an effective means of supplementing the normal carbohydrate intake in preparation for endurance races.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01466269
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    Studies on the immediate and delayed leucocytosis elicited by brief (30-min) strenuous exercise (1992)
    Springer
    European journal of applied physiology 64 (1992), S. 513-517 
    Details
    ISSN: 1439-6327
    Keywords: Leucocytes ; Lymphopenia ; Granulocytosis ; Catecholamines ; Cortisol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eight healthy male volunteers exercised for two 30-min sessions starting 3 h apart on an electronically braked cycle ergometer at a work load (mean 155.9 W, SD 33.4 W) which required an oxygen consumption that was 70% of their maximal rate of oxygen uptake. Venous blood samples were taken through an indwelling cannula over a period of 6 h beginning shortly before the first bout of exercise and were analysed for routine haematological parameters and for lactate, noradrenaline, adrenaline and cortisol. Both bouts of exercise induced an immediate leucocytosis due to rises in lymphocytes and neutrophils but only the first exercise bout induced a substantial delayed neutrophilia. In at least five subjects, changes in lymphocyte and platelet numbers were correlated (Spearman's rank procedure,P〈0.05) with simultaneous changes in the plasma concentrations of lactate, noradrenaline and adrenaline over the 6-h period studied. Increases in the plasma concentration of cortisol due to exercise correlated positively with the percentage changes in neutrophil numbers at 3 h and 6 h. These results are consistent with the suggestion that the immediate and delayed leucocytosis induced by exercise are mediated respectively by catecholamine and by cortisol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00843760
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  • 72
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    Differential mobilization of leucocyte and lymphocyte subpopulations into the circulation during endurance exercise (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 529-534 
    Details
    ISSN: 1439-6327
    Keywords: Leucocyte subpopulations ; Natural killer cells ; Catecholamines ; Endurance exercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A total of 14 healthy subjects [means (SD): 27.6 (3.8) years; body mass 77.8 (6.6) kg; height 183 (6) cm] performed endurance exercise to exhaustion at 100% of the individual anaerobic threshold (Than) on a cycle ergometer (mean workload 207 (55) W; lactate concentrations 3.4 (1.2) mmol · l−1; duration 83.8 (22.2) min, including 5 min at 50% of individual Than). Leucocyte subpopulations were measured by flow cytometry and catecholamines by radioimmunological methods. Blood samples were taken before and several times during exercise. Values were corrected for plasma volume changes and analysed using ANOVA for repeated measures. During the first 10 min of exercise, of all cell subpopulations the natural killer cells (CD3−CD16/CD56+) increased the most (229%). Also CD3÷CD16/CD56+ (84%), CD8÷CD45RO− (69%) cells, eosinophils (36%) and monocytes (62%) increased rapidly during thattime.CD3+, CD3+HLA-DR+, CD4+CD45RO+, CD4+CD45RO−, CD8+CD45RO÷ and CD19+ cells either did not increase or increased only slightly during exercise. Adrenaline and noradrenaline increased nearly linearly by 36% and 77% respectively at 10 min exercise. The increase of natural killer cells and heart rates between rest and 10 min of exercise correlated significantly (r=0.576,P=0.031). We conclude that natural killer cells, cytotoxic, non-MHC-restricted T-cells, monocytes and eosinophils are mobilized rapidly during the first minutes of endurance exercise. Both catecholamines and increased blood flow are likely to contribute this effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00602360
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    Physiological changes and gastro-intestinal symptoms as a result of ultra-endurance running (1992)
    Springer
    European journal of applied physiology 64 (1992), S. 1-8 
    Details
    ISSN: 1439-6327
    Keywords: Gastro-intestinal symptoms ; Exercise ; Cell damage ; Catecholamines ; Gastro-intestinal hormones ; Electrolytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One hundred and seventy-two competitors of the Swiss Alpine Marathon, Davos, Switzerland, 1988, volunteered for this research project. of these volunteers 170 (158 men, 12 women) finished the race (99%). The race length was 67 km with an altitude difference of 1,900 m between the highest and lowest points. Mean age was 39 (SEM 0.8) years. Average finishing times were 8 h 18 min (men) and 8 h 56 min (women). Loss of body mass averaged 3.4% body mass [mean 3.3 (SEM 0.2)%; 4.0 (SEM 0.4)%; men and women, respectively]. Blood samples from a subgroup of 89 subjects (6 women and 83 men) were taken prior to and immediately after completion of the race. Changes in haemoglobin (9.3 mmol·l−1 pre-race, 9.7 mmol·l−1 post-race) and packed cell volume (0.44 pre, 0.48 post-race) were in line with the moderate level of dehydration displayed by changes in body mass. Mean plasma volume decreased by 8.3%. No significant changes in plasma osmolality, sodium, or chloride were observed but plasma potassium did increase by 5% (4.2 mmol·l−1 pre-race, 4.4 mmol·l−1 post-race). Mean fluid consumption was 3290 (SEM 103) ml. Forty-three percent of all subjects, and 33% of those who gave blood samples, complained of gastro-intestinal (GI) distress during the race. No direct relationship was found between the quantity or quality of beverage consumed and the prevalence of GI symptoms. The circulating concentration of several GI hormones was measured and several were found to be significantly elevated (P〈0.05) after the race [mean values: gastrin 159.6 (SEM 17.8) ng·l−1; vaso-active intestinal peptide 224.3 (SEM 20.1) ng·l−1; peptide histidine isoleucine 311.1 (SEM 27.5) ng·l−1 ; motilin 214.1 (SEM 15.1) ng·l−1] but larger increases were not found to be significantly correlated with GI symptoms. Plasma cortisol, adrenaline, and noradrenaline concentrations were significantly higher after the race compared to resting values (P〈0.05). There was a trend for post-race noradrenaline values to be lower in sufferers of GI disturbance. The post-race plasma noradrenaline concentration was significantly lower specifically in those runners with intestinal cramps. Also, the resting plasma cortisol concentration was significantly lower in those individuals who developed intestinal cramps during the race. Plasma creatine phosphokinase, alanine aminotransferase and aspartate aminotransferase activities were increased following the race, which may indicate that there was tissue damage. An increase in plasma potassium concentration was observed after the race in individuals with GI complaints [0.29 (SEM 0.07) mmol·l−1 increase], whereas no increase was observed in individuals without GI symptoms. An inability of the Na+-K+ pump to keep pace with the needs of skeletal muscle (as well in the intestinal tract) may have accounted for the high plasma potassium values immediately following exercise and may have played a role in the development of GI disorders. However, many other sources of K+ release may have accounted for the elevated plasma K+ (skeletal muscle, liver and red blood cells) in such sufferers and the correlation between the increase in K+ and GI symptoms may be an indirect one.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376431
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    Training-overtraining: influence of a defined increase in training volume vs training intensity on performance, catecholamines and some metabolic parameters in experienced middle- and long-distance runners (1992)
    Springer
    European journal of applied physiology 64 (1992), S. 169-177 
    Details
    ISSN: 1439-6327
    Keywords: Training ; Overtraining ; Catecholamines ; Lipids ; Energy metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of an increase in training volume (ITV; February 1989) vs intensity (ITI; February 1990) on performance, catecholamines, energy metabolism and serum lipids was examined in two studies on eight, and nine experienced middle- or long-distance runners; seven participated in both studies. During ITV, mean training volume was doubled from 85.9 km · week−1 (pretrial phase) to 174.6 km within 3 weeks. Some 96%–98% of the training was performed at 67 (SD 8)% of maximal performance. During ITI, speed-endurance, high-speed and interval runs increased within 3 weeks from 9 km · week−1 (pretrial phase) to 22.7 km · week−1 and the total training distance from 61.6 to 84.7 km · week−1. The ITV resulted in stagnation of running velocity at 4 mmol lactate concentration and a decrease in total running distance in the increment test. Heart rate, energy metabolic parameters, nocturnal urinary catecholamine excretion, low density, very low density lipoprotein-cholesterol and triglyceride concentrations decreased significantly; the exercise-related catecholamine plasma concentrations increased at an identical exercise intensity. The ITI produced an improvement in running velocity at 4 mmol lactate concentration and in total running distance in the increment test; heart rate, energy metabolic parameters, nocturnal catecholamine excretion, and serum lipids remained nearly constant, and the exercise-related plasma catecholamine concentrations decreased at an identical exercise intensity. The ITV-related changes in metabolism and catecholamines may have indicated an exhaustion syndrome in the majority of the athletes examined but this hypothesis has to be proven by future experimental studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00717956
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    Influence of moderate cold exposure on blood lactate during incremental exercise (1992)
    Springer
    European journal of applied physiology 64 (1992), S. 213-217 
    Details
    ISSN: 1439-6327
    Keywords: Cold ; Exercise ; Lactate ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study examined the effect of exposure of the whole body to moderate cold on blood lactate produced during incremental exercise. Nine subjects were tested in a climatic chamber, the room temperature being controlled either at 30°C or at 10°C. The protocol consisted of exercise increasing in intensity in 35 W increments every 3 min until exhaustion. Oxygen consumption (VO2) was measured during the last minute of each exercise intensity. Blood samples were collected at rest and at exhaustion for the measurement of blood glucose, free fatty acid (FFA), noradrenaline (NA) and adrenaline (A) concentrations and, during the last 15 s of each exercise intensity, for the determination of blood lactate concentration [la−]b. TheVO2 was identical under both environments. At 10°C, as compared to 30°C, the lactate anaerobic threshold (Than, la −) occurred at an exercise intensity 15 W higher and [Than, la −]b was lower for submaximal intensities above the Than, la − Regardless of ambient temperature, glycaemia, A and NA concentrations were higher at exhaustion while FFA was unchanged. At exhaustion the NA concentration was greater at 10°C [15.60 (SEM 3.15) nmol·l−1] than at 30°C [8.64 (SEM 2.37) nmol·l−1]. We concluded that exposure to moderate cold influences the blood lactate produced during incremental exercise. These results suggested that vasoconstriction was partly responsible for the lower [la−]b observed for submaximal high intensities during severe cold exposure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00626283
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    Glucose metabolism by trout (Salmo trutta) red blood cells (1992)
    Springer
    Journal of comparative physiology 162 (1992), S. 448-454 
    Details
    ISSN: 1432-136X
    Keywords: Glucose metabolism ; Anaerobiosis ; Isoproterenol ; Catecholamines ; Trout, Salmo trutta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glucose metabolism has been studied in Salmo trutta red blood cells. From non-metabolizable analogue (3-O-methyl glucose and l-glucose) uptake experiments it is concluded that there is no counterpart to the membrane transport system for glucose found in mammalian red blood cells. Once within the cells, glucose is directed to CO2 and lactate formation through both the Embden-Meyerhoff and hexose monophosphate shunts; lactate appears as the most important endproduct of glucose metabolism in these cells. From experiments under anaerobic conditions, and in the presence of an inhibitor of pyruvate transfer to mitochondria, most of the CO2 formed appears to derive from the hexose monophosphate pathway. Appreciable O2 consumption has been detected, but there is no clear relationship between this and substrate metabolism. Key enzymes of glucose metabolism hexokinase, fructose-6-phosphate kinase and, probably, pyruvate kinase are out of equilibrium, confirming their regulatory activity in Salmo trutta red blood cells. The presence of isoproterenol, a catecholamine analogue, induces important changes in glucose metabolism under both aerobic and anaerobic conditions, and increases the production of both CO2 and lactate. From the data presented, glucose appears to be the major fuel for Salmo trutta red blood cells, showing a slightly different pattern of glucose metabolism from rainbow trout red blood cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00258968
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  • 77
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    Electronic Resource
    HPLC separation of catecholamines after derivatization with 9-fluorenylmethyl chloroformate (1992)
    Springer
    Chromatographia 33 (1992), S. 83-86 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Pre-derivatization ; Catecholamines ; 9-fluorenylmethyl chloroformate (FMOC-Cl)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Optimum conditions for the separation of 9-fluorenylmethyl chloroformate derivatized catecholamines by HPLC are described; three catecholamines (noradrenaline, adrenaline and dopamine) and an internal standard (epinine) were separated in less than 20 minutes under isocratic conditions. This method is 17 to 350 times more sensitive than electrochemical detection, depending on the test compounds. It has been applied to the analysis of catecholamines in urine. The sample was extracted by a metal-loaded silica prior to separation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02276857
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  • 78
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    Electronic Resource
    Gestörte alpha2-Adrenozeptorfunktion bei Hämodialysepatienten mit renaler Anämie — eine mögliche Ursache der Blutdrucksteigerung unter rekombinantem humanem Erythropoietin? (1991)
    Springer
    Journal of molecular medicine 69 (1991), S. 742-748 
    Details
    ISSN: 1432-1440
    Keywords: Human recombinant erythropoietin (rHuEPO) ; Adrenoceptors ; Anemia, renal ; Hypertension, arterial ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Nine patients on maintenance hemodialysis and transfusion-demanding renal anemia (group A) were treated with rHuEPO 120 IU/kg i.v. three times per week. Hemoglobin-content was raised from 7.2±0.9 to 10.4±0.8 g/dl. In all patients blood pressure rose, three patients developed arterial hypertension. Mean diastoloic blood pressure was 66±12 and 78±16 mmHg (p〈0.001) before and after rHuEPO. Rise in blood pressure was accompanied by a significant fall in plasma-noradrenaline-levels (from 498±100 to 383±75 pg/ml;p〈0.05) and alpha2-adrenoceptor-density (from 574±76 to 384±49;p〈0.05). Compared to nine patients on maintenance hemodialysis and hematocrit over 30% (group B), patients with severe renal anemia (group A before treatment) had higher densities of alpha2-adrenoceptors (574±76 vs. 218±32;p〈0.001) despite higher plasma-noradrenaline-levels (498±100 vs. 399±63; n.s.). We suppose a anemia-related disturbance of alpha2-receptor-function with the result of abolished receptor down-regulation and impaired vascular reagibility to vasoconstricting stimuli. With the correction of anemia receptor-function improves, receptor down-regulation as well as vascular reagibility is re-established resulting in augmented vascular resistance and higher blood pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01797612
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  • 79
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    Electronic Resource
    Β-Adrenoceptor density on mononuclear leukocytes and right atrial myocardium in infants and children with congenital heart disease (1991)
    Springer
    Journal of molecular medicine 69 (1991), S. 910-916 
    Details
    ISSN: 1432-1440
    Keywords: Β-Adrenoceptors ; Mononuclear leukocytes ; Right atrium ; Down-regulation ; Catecholamines ; Congenital heart disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sympathetic regulation of myocardial performance has been shown to be altered in congestive heart failure. Right atrial tissue of children with severe acyanotic and cyanotic congenital heart disease (CHD) showed a significantly lowerΒ-receptor density than that of children with less severe defects. Since mononuclear leukocytes (MNL) contain a homogeneous population ofΒ 2-adrenoceptors which have similar properties to those of cardiacΒ 2-adrenoceptors, they are frequently used for studying theΒ-adrenergic system. In a group of 37 children with CHD of different types and severity who underwent cardiac surgery, we compared the MNLΒ-adrenoceptor density to the type and severity of CHD and looked for a possible relationship to plasma catecholamine levels and to the right atrialΒ-adrenoceptor density. Membranes of MNL and myocardial cells were radiolabeled with (−)3-[125I]Iodocyanopindolol ([125I]ICYP). A significantly higherΒ-adrenoceptor density on MNL was found in patients with moderate acyanotic CHD (group I) than in those with severe acyanotic (group II) and cyanotic CHD (group III). Patients of group I showed approximatively 50% higher myocardialΒ-receptor density than those of groups II and III. ICI 118.551-[125I]ICYP competition studies revealed that in groups II and III significantly lower proportions and densities ofΒ 1-receptors were found compared to group I. Noradrenaline (NA) plasma levels in group II and group III were significantly higher than those in group I. The adrenaline plasma levels were found to be very high in all children with CHD. A significant negative correlation between NA levels and myocardial total andΒ 1-adrenoceptor density, but no correlation between plasma catecholamines and MNLΒ-adrenoceptor density, was calculated. We conclude that modulation of MNLΒ-adrenoceptors is not simply controlled by circulating catecholamine levels. CardiacΒ 2-adrenoceptor density remained unaltered, but theΒ 1-density was significantly lowered.Β 2-adrenoceptors on MNL showed a slight but significant decrease. However, cardiacΒ 2-adrenoceptor density cannot be predicted by measuring theΒ-adrenoceptor density on MNL.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01798537
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  • 80
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    Electronic Resource
    Neurilemoma of the retroperitoneum (1991)
    Springer
    Journal of molecular medicine 69 (1991), S. 228-231 
    Details
    ISSN: 1432-1440
    Keywords: Neurilemoma ; Retroperitoneal tumor ; Ultrasonography ; Computed tomography ; Magnetic resonance imaging ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case is presented in which suprarenal neurilemoma was associated with paroxysmal attacks of hypertension, headache and sweating with elevated plasma and urinary catecholamines. Pheochromocytoma was excluded using an overnight clonidine suppression test. Ultrasonography, computed tomography and magnetic resonance imaging, which showed cystic mass with a pedicle continuing to the widened intervertebral foramen, were helpful for the preoperative diagnosis of retroperitoneal neurilemoma. The excised tumor was revealed to be benign neurilemoma and contain detectable levels of adrenaline, noradrenaline and dopamine. The relationships between tumor catecholamines and clinical manifestations will be discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01646948
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  • 81
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    Effect of catechol oestrogens on extraneuronal metabolism of noradrenaline by rabbit uterine endometrium and myometrium (1991)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 343 (1991), S. 266-270 
    Details
    ISSN: 1432-1912
    Keywords: Catecholamines ; Catechol oestrogens ; Methoxy oestrogens ; Noradrenaline uptake ; O-Methylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of 2-hydroxy and 2-methoxy oestrogens on the extraneuronal O-methylation of 3H-(−)noradrenaline were examined in progesterone-dominated, monoamine oxidase (MAO)-inhibited, rabbit uterine tissues in vitro. Both the corticosteroid- sensitive system in myometrium and the cocaine-sensitive system in endometrium were examined. In myometrial slices preincubated with nialamide to inhibit MAO and incubated with cocaine to inhibit neuronal uptake, 3H-normetanephrine (3H-NMN) formation was inhibited in the order of potency 2-hydroxy oestrone ≥ 2-hydroxy oestradiol = 2-methoxy oestradiol ≥ 2-methoxy oestrone. In myometrial slices not exposed to cocaine and nialamide, inhibition of 3H-NMN formation by both 2-hydroxy and 2-methoxy oestradiol did not affect the formation of deaminated metabolites of 3H-(−)-noradrenaline by the alternative metabolising pathway. In endometrial slices preincubated with nialamide to inhibit MAO, only 2-hydroxy oestrogens inhibited 3H-NMN formation, but they were one to two orders of magnitude less potent in this regard than in the myometrium. The uptake of 3H-(−)-noradrenaline by MAO- and COMT-inhibited myometrial slices was inhibited by 2-hydroxy and 2-methoxy oestrogens in the order of potency 2-methoxy oestradiol ≥ 2-methoxy oestrone ≥ 2-hydroxy oestrone 〉 2-hydroxy oestradiol. Uptake of 3H-(−)-noradrenaline by endometrial slices was not affected by either 2-hydroxy or 2-methoxy oestrogens. It is concluded that the O-methylatiog system for noradrenaline in myometrial tissue is more sensitive than that in endometrial tissue to the inhibitory actions of 2-hydroxy and 2-methoxy oestrogens. 2-Hydroxy oestrogens inhibit 3H-NMN formation by competing for COMT rather than noradrenaline uptake sites, since (1) they inhibited O-methylation but not uptake of 3H-noradrenaline in endometrium and (2) 2-hydroxy oestrogens were two orders of magnitude more potent against 3H-NMN formation than 3H-(−)-noradrenaline uptake in myometrium. In contrast, the ability of 2-methoxy oestrogens to inhibit myometrial but not endometrial 3H-NMN formation reflects the selective inhibitory effect of 2-methoxy oestrogens on the corticosteroid-sensitive uptake system for noradrenaline which predominates in myometrium but is minimal in endometrium. These interactions may be important in pregnancy when the local concentrations of catechol and methoxy oestrogens rise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00251125
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  • 82
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    Intramedullary secretory gangliocytoma (1991)
    Springer
    Acta neuropathologica 82 (1991), S. 402-407 
    Details
    ISSN: 1432-0533
    Keywords: Gangliocytoma ; Ultrastructure ; Catecholamines ; Hypertension ; Spinal cord
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An 8-year-old boy developed severe systemic hypertension during resection of an intramedullary tumor. The histological, ultrastructural and immunocytochemical characteristics of the tumor are those of a gangliocytoma. Based on the demonstration of tyrosine hydroxylase in neuronal tumor cells, it is postulated that catecholamine secretion was responsible for the systemic hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296552
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  • 83
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    High density of beta2-adrenoceptors in a human keratinocyte cell line with complete epidermal differentiation capacity (HaCaT) (1991)
    Springer
    Archives of dermatological research 283 (1991), S. 328-332 
    Details
    ISSN: 1432-069X
    Keywords: Beta-adrenoceptors ; HaCaT cell line ; Catecholamines ; Membrane receptor mechanisms ; Keratinocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A non-tumorigenic keratinocyte cell line with complete epidermal differentiation capacity (HaCaT) was used in radioligand binding experiments to determine the number of beta-adrenoceptors. Intact cells were saturated with 3H-labelled (−)CGP-12177 (CGP), a hydrophilic non-selective beta-adrenergic antagonist as radioligand. In order to investigate the beta-adrenergic subtype selectivity, displacement experiments were performed with different antagonists and agonists. Binding of CGP to keratinocytes has been shown to be reversible and saturable and to have high affintiy (B max=114.0±8.8 fmol/107 cells with 6866 receptors/cell, K D=0.095±0.017 nmol/l; n=11). Betaadrenergic antagonists inhibited binding yielding monophasic displacement curves. IC50-values (nmol/l) were: propranolol (non-selective) 1.68; CGP-12177 (non-selective) 1.08; ICI 118,551 (beta2-selective) 2.92; bisoprolol (beta1-selective) 1230; and CGP-20712 (beta1-selective) 24980. Agonists displaced CGP in the order isoprenaline〉 adrenaline〉noradrenaline. We conclude that HaCaT cells express a high density of beta2-adrenoceptors providing a good model system to study adrenergic receptor mechanisms under reproducible experimental conditions in keratinocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376622
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  • 84
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    Circadian rhythmicity in the stimulation of bioluminescence by biogenic amines and MAO inhibitors inGonyaulax polyedra (1991)
    Springer
    International journal of biometeorology 34 (1991), S. 231-234 
    Details
    ISSN: 1432-1254
    Keywords: Catecholamines ; Circadian rhythms ; Dinoflagellates ; Indoleamines ; MAO inhibitors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract In the dinoflagellateGonyaulax polyedra bioluminescence was investigated in constant darkness. Light emission was stimulated considerably and specifically by the biogenic smines epinephrine, 5-methoxytryptamine, and kynuramine. Various analogues and motabolites of these substances, such as norepinephrine, isoproterenol, phenylephrine, synephrine, metanephrine isoproterenol, phenylephrine, synephrine, metanephrine dopamine, 3,4-dihydroxymandelic and 3-methoxy hydroxymandelic acids, serotonin, N-acetylserotonin, melatonin, 5-hydroxytryptophol, 5-methoxytryptophol, kynurenine, 4-hydroxyquinoline, 3-hydroxyanthrani ic, and quinolinic acids were much less effective. Strong enhancement of bioluminescence, in the range of those obtained with the three stimulatory biogenic amines was also observed after administration of several compeunds acting as MAO inhibitors in mammalian systems, in particular, pargyline, amitriptyline,p-benzoquinone, tranylcypromine, harmaline, and noreleagnine. The responsiveness of cells towards epinephrine, 5-methoxytryptamine, kynuramine, amitriptyline,p-benzoquinone, and noreleagnine varied considerably within the circadian cycle, with the highest stimulations obtained during subjective night. These rhythms can be only partially explained by periodic bioluminescence capacity, and seem to comprise a cyclicity in the sensitivity of cells to the compounds mentioned.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01041834
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  • 85
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    Mood responses of remitted schizophrenics to methylphenidate infusion (1991)
    Springer
    Psychopharmacology 105 (1991), S. 247-252 
    Details
    ISSN: 1432-2072
    Keywords: Psychostimulants ; Methylphenidate ; Schizophrenia ; Schizoaffective disorder ; Mood response ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate the mood response of schizophrenic subjects to psychostimulant challenge, 29 neuroleptic-treated subjects (22 with schizophrenia and 7 with schizoaffective disorder) in clinical remission received two infusions, one with methylphenidate 0.5 mg/kg and the other with normal saline, under double-blind conditions. Twenty-five of these subjects were withdrawn from neuroleptics and given a second set of double-blind infusions. Infusion mood responses were classified as euphoric, neutral, mixed or dysphoric. Subjects were also rated as either psychotic symptom activators to the infusion or no change in psychotic symptoms. Overall response by mood category was as follows: 35.2% euphoric, 50% neutral, 5.6% mixed and 9.3% dysphoric. Mood responses were not correlated with sex, methylphenidate plasma levels or diagnostic distinctions between schizophrenia and schizoaffective disorder. Although they occurred infrequently, dysphoric and mixed mood responses were associated with high rates of psychotic activation. Comparing subjects on and off neuroleptics, subjects on neuroleptics had more euphoric responses than the same subjects off neuroleptics. This increased number of euphoric responses in subjects taking neuroleptics compared to off neuroleptics suggests that neuroleptic treatment status may be an important factor in assessing psychostimulant use in schizophrenia patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244317
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  • 86
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    Electronic Resource
    Localization of dopamine-1 receptors along the microdissected rat nephron (1991)
    Springer
    Pflügers Archiv 419 (1991), S. 243-248 
    Details
    ISSN: 1432-2013
    Keywords: Na/K-ATPase ; Fenoldopam ; DA1 receptors ; Isolated tubules ; Glomeruli ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dopamine exerts numerous actions on the kidney but the precise location of its receptor subtypes along the nephron is unknown. Using a microassay we determined the specific binding of 125I-Sch 23982, a specific and selective dopamine-1 (DA1) receptor antagonist, to microdissected glomeruli and tubule segments. Binding of 125I-Sch 23982 in the proximal convoluted tubule (PCT) was timeand concentration dependent, saturable and reversible. The linear Scatchard plot of saturation experiments suggested binding to a single site with an apparent K d of 16.7 nM and B max of 0.4 fmol·mm−1 in the PCT, and 6.2 nM and 0.1 fmol·mm−1 in the cortical collecting tubule (CCT). Mapping of DA1 binding sites along the nephron revealed their presence in each of the segments examined, albeit in markedly different concentrations: the highest specific binding was measured in PCT followed by the pars recta. Binding was less in the distal nephron, and least in the medullary and cortical thick ascending limb. Modest binding was also detected in glomeruli. In cortical collecting tubules competition studies with unlabeled dopamine and probes for DA1 (Sch 23390, fenoldopam), DA2 (domperidone, S-sulpiride), serotonergic (serotonin, ketanserin, mianserin), and α-(phentolamine) and β-(propranolol) adrenergic receptors indicated a rank-order potency for displacement of 125I-Sch 23982 binding, consistent with labeling of DA1 receptors. Dopamine inhibited Na/K-ATPase both in PCT and CCT, an effect duplicated in the latter segment by the DA1 agonist fenoldopam, and blocked by the DA1 antagonist Sch 23390. These results demonstrate specific DA1 binding sites in a nonhomogeneous pattern along the entire nephron, and suggest that dopamine may exert its effect on Na transport in distal as well as in proximal nephron segments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00371102
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  • 87
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    Electronic Resource
    Myocardial β-adrenoceptor density and the distribution of 388-1388-1388-1388-2388-2388-2subpopulations in children with congenital heart disease (1991)
    Springer
    European journal of pediatrics 150 (1991), S. 388-394 
    Details
    ISSN: 1432-1076
    Keywords: β-adrenoceptors ; Down-regulation ; Catecholamines ; Congenital heart disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Twenty-six infants and children with congenital heart disease (CHD) undergoing cardiac surgery were investigated for alterations in myocardial β-adrenoceptor density. The patients were divided into three groups according to type and severity of CHD: group I consisted of 6 patients with acyanotic shunt lesions of moderate severity; group II comprised 13 children with severe acyanotic shunt and valve lesions and group III included 7 children with cyanotic CHD. The myocardial β-adrenoceptor density was determined using (−)3-[125I] Iodocyanopindolol ([125I]ICYP) and was reduced by approximately 50% in severe acyanotic CHD (33.6 fmol/mg protein) and cyanotic CHD (35.3 fmol/mg protein) in comparison with the group with less severe acyanotic shunt defects (64.4 fmol/mg protein). The affinity dissociation constant (K d, ICYP) did not differ statistically between the groups. The proportion of β1- and β1-subpopulation was evaluated by ICI 118,551-[125I]ICYP competition studies. In group II (61.5%) and group III (69.1%) significant lower portions of β1-adrenoceptors were found compared with group I (78.2%). This shift of subpopulations was due to a decreased β1-receptor density while β2-receptor density was unchanged in all groups. While the plasma noradrenaline levels of group I were similar to those of a control group of 13 healthy children, respective values of group II and III were significantly elevated. A significant negative correlation was found between plasma noradrenaline levels and myocardial β-adrenoceptor density. It is concluded that exposure of these receptors to increased circulating catecholamines, due to an enhanced sympathetic tone, leads to a reduction of their density. Noradrenaline, a preferential agonist of β1-adrenoceptors, is most probably responsible for the shift of the β-adrenoceptor subpopulations from the β1- to β2-subtype, depending on severity and type of cardiac disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02093715
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  • 88
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    Chronic effects of methylmercury on the urinary excretion of catecholamines and their responses to hypoglycemic stress (1991)
    Springer
    Archives of toxicology 65 (1991), S. 164-167 
    Details
    ISSN: 1432-0738
    Keywords: Methylmercury (MeHg) ; Catecholamines ; Hypoglycemic stress ; Sympathetic nervous system ; Nephrotoxicity ; Thyroidal functions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Five male Wistar rats were treated with methyl-mercury chloride (MMC) and compared with five agematched control rats. A dose of 10 mg/kg was given three times. The chronic effects of the MMC administration on the urinary output of catecholamines [norepinephrine (NE), epinephrine (E) and dopamine (DA)] were measured for 50 days. On the 69th day after MMC administration, the rats were examined for insulin-induced hypoglycemic stress. On the 90th day, the animals were decapitated and various organs were weighed and serum thyroid hormones [thyroid stimulating hormone (TSH) and total and free thyroxine (T4)] were measured. Decreases in DA excretion and DA response to stress were observed in the MMC-treated group. Inflammation of the kidney was also found, suggesting MMC-induced damage to the renal tubular region, the apparent site of renal DA synthesis. The MMC group and the control group showed differential NE and E response patterns. The lowered baseline excretion of NE appeared to continue even 70 days after MMC administration, while the difference in E excretion between the two groups disappeared 1 month after MMC administration. Both NE and E showed normal responsiveness to hypoglycemic stress induced by insulin. All serum TSH and total and free T4 baseline levels showed slight increases, and the thyroid gland weights in the MMC group were slightly heavier. These findings suggest a rather hyperthyroid state after the initial acute phase suppression, as suggested by the previous examinations. Thus, these findings suggest long-lasting effects of methylmercury administration, especially on renal DA synthesis. Baseline urinary excretion of NE and thyroid function could also be affected for a long time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02034946
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  • 89
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    Social rank and brain levels of monoamines and monoamine metabolites in Arctic charr, Salvelinus alpinus (L.) (1991)
    Springer
    Journal of comparative physiology 168 (1991), S. 241-246 
    Details
    ISSN: 1432-1351
    Keywords: Arctic charr ; Dominance hierarchy ; Aggression ; Catecholamines ; Serotonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dominance hierarchy was determined in 5 groups of juvenile Arctic charr (Salvelinus alpinus), each group consisting of 4 fish. Telencephalon and brain stem (remaining parts of the brain) were analyzed with regard to their content of monoamines and monoamine metabolites. No significant differences were observed in the concentrations of norepinephrine (NE), dopamine (DA), or serotonin (5-hydroxytryptamine, 5-HT) between fish with different social rank. However, the concentration of 5-hydroxyindoleacetic acid (5-HIAA), the principle metabolite of 5-HT, was significantly higher in subordinate fish, and a significant inverse linear correlation was found between 5-HIAA concentration and social rank (as measured by dominance index) in the brain stem. In the telencephalon the dominant fish had a significantly higher level of homovanillic acid (HVA), a major DA metabolite. These findings indicate a greater serotonergic activity, possibly associated with increased stress, as well as a lower dopaminergic activity, possibly associated with reduced aggression, in subordinate charr. The differences between dominant and subordinate fish could either be caused by social interactions or reflect innate individual differences in monoamine utilization, predisposing individuals for dominant or subordinate positions in the dominance hierarchy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218416
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  • 90
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    Dose-dependent effects of intravenous lorazepam on cardiovascular activity, plasma catecholamines and psychological function during rest and mental stress (1991)
    Springer
    Psychopharmacology 105 (1991), S. 77-83 
    Details
    ISSN: 1432-2072
    Keywords: Lorazepam IV ; Catecholamines ; Blood pressure ; Heart rate ; Performance tasks ; Subjective mood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dose-dependent effects of intravenously administered lorazepam on psychophysiological activity during rest and mental stress were studied in order to examine differential responses to doses which may induce anxiolysis or sedation. In a double-blind randomized cross-over study, nine male volunteers participated in a placebo and a lorazepam session, during which the subjects repeatedly performed a 10-min version of the Stroop Color Word Test (CWT), with 10 min of rest between the CWTs. Lorazepam was administered before each rest period in increasing doses of 0.0, 0.06, 0.13, 0.25 and 0.5 mg (total cumulative dose: 0.94 mg). Heart rate showed a dose-dependent decrease during rest with an ED50 of 0.13 mg lorazepam, while lorazepam had no effect on the cardiovascular and plasma catecholamine response magnitudes to the CWT. Subjective fatigue and reaction time increased significantly after 0.94 mg lorazepam, while at the same dose vigor decreased; state anxiety after the CWT was not influenced by lorazepam. These data show differential effects of lorazepam on cardiovascular, biochemical and psychological function. While heart rate was suppressed at low doses during rest and reaction time and subjective fatigue increased at doses which induced sedation, state anxiety and physiological response patterns to the CWT were not influenced by lorazepam.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02316867
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  • 91
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    Naloxone blockade of amphetamine place preference conditioning (1991)
    Springer
    Psychopharmacology 104 (1991), S. 265-274 
    Details
    ISSN: 1432-2072
    Keywords: d-Amphetamine ; Naloxone ; Place conditioning ; Conditioned place preference ; Reward ; Reinforcement ; Endogenous opioids ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Amphetamine and naloxone were examined in place conditioning, in order to study possible interactions between endogenous opioids and catecholamines in reinforcement. After initial preferences were determined, animals were conditioned with amphetamine alone (1.0 mg/kg SC), naloxone alone (0.02, 0.2 or 2.0 mg/kg SC) or combinations of amphetamine plus naloxone. A reliable, long-lasting preference for the compartment associated with amphetamine was observed, reflecting the reinforcing properties of this drug. No preference or aversion was observed in animals that received saline in both compartments. Naloxone (0.02, 0.2 and 2.0 mg/kg) produced a dose-dependent place aversion; while the lowest dose had effects similar to saline, the higher doses produced significant place aversions. Naloxone, at all three doses examined, prevented the ability of amphetamine to produce a place preference. Thus, the lowest dose of naloxone, having no effects alone in place conditioning was still able to block the reinforcing effects of amphetamine. These results suggest that the reinforcing effects of amphetamine are dependent on activation of opiate receptors, and provide further evidence that interactions between endogenous opioids and catecholamines may be important in reinforcement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244190
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  • 92
    Electronic Resource
    Electronic Resource
    Release of endogenous catecholamines in two different regions of the nucleus of the solitary tract as influenced by carotid occlusion (1991)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 343 (1991), S. 155-160 
    Details
    ISSN: 1432-1912
    Keywords: Push-pull cannula ; Rostral nucleus of the solitary tract (NTS) ; Intermediate nucleus of the solitary tract ; Catecholamines ; Carotid occlusion ; Release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of carotid occlusion on the release of catecholamines in the nucleus of the solitary tract (NTS) were investigated in anaesthetized cats. Two aspects of the nucleus (rostral or intermediate NTS) were superfused bilaterally through push-pull cannulae with artificial CSF and the release of the endogenous dopamine, noradrenaline and adrenaline was determined in the superfusate radioenzymatically. The superfusion rate was 150 μl/min or 800 μl/min. In some experiments, superfusion of the intermediate NTS was carried out after denervation of the aortic arch. In the rostral NTS superfused at a rate of 150 μl/min, bilateral carotid occlusion led to a rise in blood pressure and decreased the release rate of dopamine. These changes continued after occlusion termination. The release rate of noradrenaline was transiently diminished during occlusion. The release of this amine was also decreased after occlusion termination. The release rate of adrenaline was not influenced during carotid occlusion, but it was found to be diminished after termination of the occlusion. Superfusion of the rostral NTS at a rate of 800 μl/min also reduced the release rate of adrenaline after termination of carotid artery occlusion. In the intermediate NTS (superfusion rate 150 μl/min) similar effects of the carotid occlusion on the release rates of dopamine and noradrenaline were observed. In this aspect of the NTS, denervation of the aortic arch abolished the decrease in the noradrenaline release during carotic occlusion, while the release rates of dopamine and adrenaline were decreased during and after termination of the carotid occlusion. The results suggest that (a) the rise in blood pressure in the carotid sinus after termination of a carotid occlusion decreases the release rates of noradrenaline and adrenaline in the NTS, (b) the decrease in the release of noradrenaline during carotid occlusion is due to impulses originating from the baroreceptors of the aortic arch. Thus, impulses from carotid sinus and aortic arch modify the release rates of noradrenaline in the NTS so as to counteract blood pressure changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00168603
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  • 93
    Electronic Resource
    Electronic Resource
    The structural organization and the steroidogenic responsiveness in vitro of adrenal gland tissue from the neonatal mallard duck (Anas platyrhynchos) (1991)
    Springer
    Cell & tissue research 263 (1991), S. 557-566 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Chromaffin tissue ; Steroidogenesis ; ACTH ; Angiotensin II ; Catecholamines ; Acetylcholine ; Neonatal mallard duckling (Aves, Anatiformes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenal steroidogenic tissue of the neonatal mallard duckling is differentiated into an outer subcapsular zone where the cells contain many large lipid droplets, and an inner zone in which the cells appear to contain less lipid. The cells in both zones contain numerous mitochondria and an abundance of smooth endoplasmic reticulum, and their interdigitating plasma membranes possess many filipodia, coated pits and desmosome-like junctions. Islands of chromaffin cells are distributed throughout the steroidogenic tissue. Two types of chromaffin cell are present, one with vesicles containing densely staining material and the other more lightly staining material. Non-myelinated preganglionic fibers synapse with the chromaffin cells and the axonal terminals contain two types of dense-cored vesicles as well as acetylcholine-containing vesicles. The basal rates of corticosterone (B) and aldosterone (Aldo) release from tissue superfused with buffer containing no secretogogue were low and almost equal (B: Aldo=1.25); the corresponding rate of deoxycorticosterone (DOC) release was less than one-fortieth of the rates of B and Aldo release. The addition of 1–24 ACTH to the medium caused the rate of release of each hormone to increase as a semi-logarithmic function of the concentration and the induced increase in B release was always significantly higher than that of Aldo (B: Aldo=4.8). The corticotropin-induced rates of B and Aldo, but not DOC, release reflected do novo hormone synthesis. Norepinephrine, epinephrine and dopamine each suppressed the basal rates of B and Aldo release, but had no effect when the medium contained 1–24 ACTH. Acetylcholine (ACh) similarly suppressed the basal rates of hormone release, and neither suppressed nor enhanced the responses to medium containing 1–24 ACTH. The suppressive effects of the catecholamines and ACh were not dose-related. [Asp1, Val5] angiotensin II induced significant semi-logarithmic dose-dependent increases in Aldo synthesis but had no effect on the release of either B or DOC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327289
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  • 94
    Electronic Resource
    Electronic Resource
    The catecholaminergic system of an annelid (Ophryotrocha puerilis, Polychaeta) (1991)
    Springer
    Cell & tissue research 265 (1991), S. 175-184 
    Details
    ISSN: 1432-0878
    Keywords: Nervous system ; Nervous system, peripheral ; Catecholamines ; Immunohistochemistry ; Glyoxylic acid fluorescence ; Ophryotrocha puerilis (Annelida)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The complex catecholaminergic (CA) nervous system of the polychaete Ophryotrocha puerilis is documented using glyoxylic acid induced fluorescence (GIF) and immunohistochemistry. CA-neurons are found both in the central and peripheral nervous system. In the brain, about 50 CA-neurons are present in the perikaryal layer together with numerous CA fibres. Two pairs of CA perikarya are characteristic for each ganglion of the ventral nerve cord. CA-neurites in the ventral nerve cord are mainly arranged in 4 strands paralleling the longitudinal axis of the worm. Fluorescent neurons with receptive ciliary structures are present in body appendages (antennae, palps, urites, parapodial cirri), in the body-wall, and within the oesophageal wall. Furthermore, a subepidermal nerve net of free CA nerve endings has been found. After incubation of specimens with dopamine prior to the development of GIF more fluorescent perikarya could be observed; the fluorescence was also intensified. Pre-incubation with reserpine reduced the intensity of GIF. Results of high pressure liquid chromatography and immunostaining with a polyclonal antibody against a dopamine-glutaraldehyde-complex suggest that dopamine is the major CA transmitter. It is thought that dopaminergic neurons together with ciliary receptive structures act as mechano- and/or chemoreceptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318152
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  • 95
    Electronic Resource
    Electronic Resource
    Cytophysiology of neurosecretory axon terminals in the brain of an annelid (Ophryotrocha puerilis, Polychaeta) (1991)
    Springer
    Cell & tissue research 264 (1991), S. 339-345 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Catecholamines ; HPLC ; Immunohistochemistry ; Glyoxylic acid fluorescence ; Ophryotrocha puerilis (Annelida)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the posterior part of the brain of the protandric polychaete Ophryotrocha puerilis neurosecretory cells form prominent axon terminals. The terminals are arranged in two complexes. The perikarya of these presumably monopolar neurons are scattered in the anterior part of the cerebral perikaryal layer. In females the terminals store large amounts of neurosecretory material. It has been suggested earlier that neurosecretions of the terminals may play a role during sex reversal from females to males. Application of histamine caused the release of neurosecretory material from the respective terminals in females. However, this discharge was not followed by sex reversal. Application of reserpine had no influence on the terminals. Neither by in vivo observation nor by ultrastructural analysis any effect of reserpine on the terminal complexes could be observed. In isolated terminals filled with neurosecretory material from females, catecholamines could not be detected by HPLC. Also, polyclonal antibodies against dopamine did not stain the terminal complexes. Furthermore, the complexes did not develop any fluorescence after glyoxylic acid treatment. Therefore, the present results contradict the hypothesis that the neurosecretory material of the respective axon terminals is catecholaminergic and that it is involved in sex differentiation. The function of the secretory neurons studied here remains unclear.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00313972
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  • 96
    Electronic Resource
    Electronic Resource
    Effects of carbohydrate type on postprandial blood pressure, neuroendocrine and gastrointestinal hormone changes in the elderly (1991)
    Springer
    Clinical autonomic research 1 (1991), S. 219-224 
    Details
    ISSN: 1619-1560
    Keywords: Postprandial hypotension ; Elderly ; Carbohydrate ; Neurotensin ; Catecholamines ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous studies have demonstrated that blood pressure falls postprandially in fit elderly subjects, the greatest changes occurring after meals with a high carbohydrate content. To evaluate the influence of the type of carbohydrate on postprandial blood pressure, the effects of equivalent energy content (2.4 MJ) high complex (starch) and high simple (monosaccharide) carbohydrate meals were studied in seven healthy elderly subjects. Blood pressure, heart rate, autonomic function, plasma catecholamines, insulin and neurotensin levels were measured pre- and postprandially. Greater falls in supine and erect systolic blood pressure occurred after the high simple than the high complex carbohydrate meal (p 〈 0.05). No differences were found in supine or erect diastolic blood pressure, heart rate or in any of the biochemical parameters measured between the meal types. It is concluded that a simple carbohydrate meal results in a greater postprandial fall in blood pressure than an equivalent energy complex carbohydrate meal in the elderly, although the mechanisms for these changes are unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01824990
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  • 97
    Electronic Resource
    Electronic Resource
    Cardiovascular instability and baroreflex activity in a patient with tetanus (1991)
    Springer
    Clinical autonomic research 1 (1991), S. 5-8 
    Details
    ISSN: 1619-1560
    Keywords: Blood pressure ; Heart rate ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a patient with tetanus we tested the hypothesis that the hyperadrenergic cardiovascular instability might be due to impairment of the baroreceptor reflex by the tetanus toxin. Baroreflex sensitivity assessed with the phenylephrine method was found to be normal. Changes in arterial pressure correlated inversely with relative changes in plasma volume but not with plasma catecholamine levels. There were both extreme hypo- and hyperadrenergic episodes. We conclude that sympathetic overactivity in tetauns temporarily overrules a functionally intact baroreflex leading to severe blood pressure instability with episodes of hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01826051
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  • 98
    Electronic Resource
    Electronic Resource
    Hormonal regulation of potassium shifts during graded exhausting exercise (1991)
    Springer
    European journal of applied physiology 62 (1991), S. 292-296 
    Details
    ISSN: 1439-6327
    Keywords: Potassium ; Catecholamines ; Cyclic AMP ; Exercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Serum potassium, aldosterone and insulin, and plasma adrenaline, noradrenaline and cyclic adenosine 3′:5′-monophosphate (cAMP) concentrations were measured during graded exhausting exercise and during the following 30 min recovery period in six untrained young men. During exercise there was an increase in concentration of serum potassium (4.74 mmol·1−1, SEM 0.12 at the end of exercise vs 3.80 mmol·1−1, SEM 0.05 basal,P〈0.001), plasma adrenaline (2.14 nmol·1−1, SEM 0.05 at the end of exercise vs 0.30 nmol·1−1, SEM 0.02 basal,P〈0.001), plasma noradrenaline (1.10 nmol·1−1, SEM 0.64 at the end of exercise vs 1.50 nmol·1−1, SEM 0.05 basal,P〈 0.001), serum aldosterone (0.92 nmol·1−1, SEM 0.14 at the end of exercise vs 0.36 nmol·1−1, SEM 0.05 basal,P〈0.01), and plasma cAMP (35.4 nmol·1−1, SEM 2.3 at the end of exercise vs 21.4 nmol·1−1, SEM 4.5 basal,P〈0.05). While concentrations of serum potassium, plasma adrenaline and cAMP returned to their basal levels immediately after exercise, those of plasma noradrenaline and serum aldosterone remained elevated 30 min later (1.90 nmol·1−1, SEM 0.01,P〈0.01; and 0.85 nmol·1−1, SEM 0.12,P〈0.01, respectively). Serum insulin concentration did not change during exercise (6.47 mlU·1−1, SEM 0.58 at the end of exercise vs 5.47 mlU·1−1, SEM 0.41 basal, NS) but increased significantly (P〈0.02) at the end of the recovery period (7.12 mlU·1−1, SEM 0.65). Serum potassium increases with exhausting exercise appeared to be caused not only by its release from contracting muscles but also by an α-adrenergic stimulation produced by adrenaline and noradrenaline. On the other hand, the increased levels of plasma noradrenaline maintained during the recovery period may have served to avoid excessive hypokalaemia through the stimulation of muscle α-receptors. Thus, catecholamines may play an important role in the regulation of serum potassium concentrations during and after exercise. Any disturbance of these adrenergic effects may lead either to an excessive increase or to a decrease of kalaemia, with the consequent risk of arrhythmias linked to exercise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571555
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  • 99
    Electronic Resource
    Electronic Resource
    Effect of beta-adrenergic blockade on plasma lactate concentration during exercise at high altitude (1991)
    Springer
    European journal of applied physiology 63 (1991), S. 315-322 
    Details
    ISSN: 1439-6327
    Keywords: Acclimatization ; Altitude ; Hypoxia ; Catecholamines ; Propranolol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary When unacclimatized lowlanders exercise at high altitude, blood lactate concentration rises higher than at sea level, but lactate accumulation is attenuated after acclimatization. These responses could result from the effects of acute and chronic hypoxia on β-adrenergic stimulation. In this investigation, the effects of β-adrenergic blockade on blood lactate and other metabolites were studied in lowland residents during 30 min of steady-state exercise at sea level and on days 3, 8, and 20 of residence at 4300 m. Starting 3 days before ascent and through day 15 at high altitude, six men received propranolol (80 mg three times daily) and six received placebo. Plasma lactate accumulation was reduced in propranolol- but not placebo-treated subjects during exercise on day 3 at high altitude compared to sea-level exercise of the same percentage maximal oxygen uptake ( $$\dot VO_{2max}$$ ). Plasma lactate accumulation exercise on day 20 at high altitude was reduced in both placebo- and propranolol-treated subjects compared to exercise of the same percentage $$\dot VO_{2max}$$ performed at sea level. The blunted lactate accumulation during exercise on day 20 at high altitude was associated with reduced muscle glycogen utilization. Thus, increased plasma lactate accumulation in unacclimatized low-landers exercising at high altitude appears to be due to increased β-adrenergic stimulation. However, acclimatization-induced changes in muscle glycogen utilization and plasma lactate accumulation are not adaptations to chronically increased β-adrenergic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00364456
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  • 100
    Electronic Resource
    Electronic Resource
    Plasma epinephrine and norepinephrine during anesthesia in a patient with orthostatic hypotension (1991)
    Springer
    Journal of anesthesia 5 (1991), S. 416-418 
    Details
    ISSN: 1438-8359
    Keywords: Orthostatic hypotension ; Catecholamines ; Enflurane anesthesia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s0054010050416
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