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  • 1
    Electronic Resource
    Electronic Resource
    Über den Einfluß der extracellulären Wasserstoffionenkonzentration auf die Wirkung kreislaufaktiver Pharmaka (1971)
    Springer
    Clinical and experimental medicine 154 (1971), S. 165-176 
    Details
    ISSN: 1591-9528
    Keywords: Blood-pH ; resp. Acidosis ; Cardiovascular Drugs ; Blut-pH ; resp. Acidose ; kreislaufaktive Pharmaka
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Elektrisch gereizte Vorhofpräparate des Meerschweinchens wurden in einem Tyrodebad suspendiert, dessen pH durch Begasung mit verschiedenen CO2-Konzentrationen auf 7,0, 7,4 bzw. 7,8 eingestellt wurde. Kontraktionskraft und maximale Kontraktionsgeschwindigkeit der Vorhöfe wurden durch diese pH-Änderungen nicht beeinflußt. Der positiv inotrope Effekt von Tyramin, Isoproterenol und Calcium war bei pH 7,0 abgeschwächt, bei pH 7,8 verstärkt. An narkotisierten Katzen wurde durch Beatmung mit 10 bzw. 20% CO2 eine respiratorische Acidose mit pH-Werten von 7,15 bzw. 7,0 erzeugt. Dabei traten eine mäßige Zunahme der Herzfrequenz, der maximalen Druckanstiegsgeschwindigkeit (dp/dtmax) und des systolischen Femoralisdruckes ein. Die Wirkung aller untersuchten Pharmaka war in Acidose abgeschwächt, wobei sich aber folgende quantitative und qualitative Unterschiede ergaben: 1. Die blutdrucksenkende Wirkung des Isoproterenols und die blutdrucksteigernde Wirkung des Noradrenalins waren stärker abgeschwächt als ihre positiv inotrope Wirkung am Herzen. 2. Die pressorische Wirkung des Angiotensins und Noradrenalins war weniger beeinträchtigt als die des Naphazolins. 3. Die blutdrucksenkende Wirkung des Acetylcholins war im Gegensatz zu der des Isoproterenols weniger abgeschwächt.
    Notes: Summary Experiments were performed on guinea pigs isolated atria which were stimulated electrically. If the pH of the tyrode solution was changed by variation of pCO2 no alteration of force of contraction and maximal velocity of contraction (dT/dtmax.) occured. The inotropic effects of tyramine, isoproterenol and calcium were diminished at pH 7.0 and increased at pH 7.8. During respiratory acidosis (pH 7.0) anaesthetized cats showed a small increase in heart rate, left ventricular dp/dtmax. and arterial blood pressure. The effects of all tested drugs were diminished in acidosis, whereby the following qualitative and quantitative differences appeared: 1. The depressive effect of isoproterenol and the stimulating effect of norepinephrine on arterial blood pressure were much more diminished than the positive inotropic effect of these drugs. 2. The effect of angiotensin and norepinephrine on arterial blood pressure was less affected than that of naphazoline. 3. The effect of acetylcholine on arterial blood pressure was scarcely diminished in contrast to that of isoproterenol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02048388
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of respiratory acidosis on heart and circulation in cats, pigs, dogs and rabbits (1972)
    Springer
    Research in experimental medicine 158 (1972), S. 308-320 
    Details
    ISSN: 1433-8580
    Keywords: Respiratory Acidosis ; Cardiovascular Effects ; Sympathomimetic Amines ; Species Differences ; Respiratorische Acidose ; Kreislauf ; Sympathomimetica ; Speciesunterschiede
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Katzen, Hunden, Kaninchen und Hausschweinen wurden in Pentobarbitalnarkose nach Muskelrelaxation mit Alloferin® bei geschlossenem Thorax die Auswirkungen einer akuten respiratorischen Acidose auf den Kreislauf sowie dessen Reaktion auf Pharmaka untersucht. 1. BeiKatzen undSchweinen steigen in respiratorischer Acidose Herzfrequenz, dp/dtmax und Blutdruck an; beiKaninchen bleiben dp/dtmax und Blutdruck nahezu unverändert. BeiHunden hingegen sinken Schlagfrequenz, dp/dtmax und Blutdruck in Acidose ab. Untersuchungen an Katzen, die mit Reserpin vorbehandelt waren, zeigten, daß eine respiratorische Acidose einen negativ inotropen und blutdrucksenkenden Eigeneffekt besitzt. Nach Vorbehandlung mit Phenoxybenzamin verursacht eine respiratorische Acidose bei Katzen einen Blutdruckabfall sowie einen Anstieg von dp/dtmax. Nach Vorbehandlung mit Pindolol verursacht eine Acidose eine Abnahme von Frequenz und dp/dtmax, während der Blutdruck konstant bleibt. Am unvorbehandelten Tier wird der negativ inotrope Effekt einer Acidose offenbar durch eine Stimulierung des sympathischen Nervensystems überdeckt, die bei Katzen und Schweinen am ausgeprägtesten ist. 2. DieWirkung sympathomimetischer Amine auf Herz und Kreislauf ist bei allen 4 untersuchten Tierarten in Acidose abgeschwächt, wobei die Abschwächung bei den Tieren mit der stärksten sympathischen Stimulation am ausgeprägtesten ist. 3. Biochemische Untersuchungen an Hunden und Katzen ergaben, daß in Acidose K+, Mg2+, anorganisches Phosphat und Glucose im Serum ansteigen, während der Magnesiumgehalt des Herzmuskels abnimmt.
    Notes: Summary In closed chest cats, dogs, rabbits and pigs, anaesthetized with pentobarbital and relaxed with diallylnortoxiferinium dichloride the effects of a respiratory acidosis on heart and circulation as well as their reaction to sympathomimetic amines were studied. 1. Incats andpigs a respiratory acidosis causes a rise of frequency, dp/dtmax of the left ventricle and systolic blood-pressure. Inrabbits an acidosis causes no significant alteration of blood-pressure and dp/dtmax. Indogs frequency, dp/dtmax and blood-pressure decline in acidosis. In cats pretreated withreserpine a respiratory acidosis causes a negative inotropic effect and a declining of blood-pressure. After pretreating cats withphenoxybenzamine in acidosis there results a decrease of blood-pressure, but a rise of dp/dtmax and frequency; after pretreating withpindolol in acidosis dp/dtmax and frequency decline, but blood-pressure remains unaltered. 2. The effectiveness of sympathomimetic amines on heart and circulation is diminished in acidosis. This diminution is most significant in those animals (cat, pig) with the most augmented sympathetic tonus in acidosis, but experiments performed with reserpinized cats indicated that the augmented sympathetic tonus can not be the only cause for the diminished efficiency of adrenergic stimulant amines in acidosis. 3. Biochemical studies performed in acidosis showed a rise of K+, Mg2+, inorganic phosphate and glucose in serum and a decrease of Mg2+ in the heart muscle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01852214
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  • 3
    Electronic Resource
    Electronic Resource
    Effect of cyclophosphamide pretreatment of pregnant animals on the activity of nuclear DNA-dependent RNA-polymerases in different parts of rat embryos (1973)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 277 (1973), S. 71-88 
    Details
    ISSN: 1432-1912
    Keywords: Cyclophosphamide ; Embryonic Development ; DNA-Dependent RNA Polymerases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary On day 13+0 h of gestation rats received 10 mg/kg cyclophosphamide i.p. 3, 9, and 24 h after administration of the drug the activities of the DNA-dependent RNA polymerase reactions were measured in the whole embryo and in parts of it (head, upper and lower extremities and trunk). The activities of these enzymes were correlated with the increase in the RNA content of these tissues. A relationship was established light and electron microscopically between the biochemical results and the specific alterations which occur in different structures of the embryonic tissue. The results of these investigations show that: 1. cyclophosphamide leads-in dependency on the time-to a decrease or increase in the Mn++- and/or Mg++-stimulated RNA polymerase reactions in isolated cell nuclei of individual parts of the embryo 2. alterations in the enzyme activities of individual parts of the embryo are not detected when the enzyme activity of the whole embryo is measured at the early day 13 of gestation 3. towards the end of gestation malformations can be demonstrated only in those parts of the embryo, where 24 h after the administration of cyclophosphamide the enzyme pattern shows a highly significant deviation from that of the controls and where cell necroses can be demonstrated light and electron microscopically. Moreover, in the nucleolus of the neuroepithelium segregation of its components takes place which correlates well with the decreased r-RNA polymerase activity. In this paper a disturbance of the transcription mechanisms is discussed as being the primary mode of action of cyclophosphamide in cell metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498786
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  • 4
    Electronic Resource
    Electronic Resource
    The effects of isoprenaline and tyramine on the 45calcium uptake, the total calcium content and the contraction force of isolated guinea-pig atria in dependence on different extracellular hydrogen ion concentrations (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 274 (1972), S. 125-137 
    Details
    ISSN: 1432-1912
    Keywords: Sympathomimetic Amines ; pH ; 45Calcium Uptake ; Contraction Force ; Guinea-Pig Atria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated, electrically stimulated left guinea-pig atria were incubated at 30° C in a Tyrode solution, the hydrogen ion concentration of which was varied by altering the percentage of the aerating CO2/O2-mixture. The increase of the extracellular hydrogen ion concentration from pH 8.0 to pH 7.0 caused a reduction of the 45calcium uptake and of the contraction force. The positive inotropic effect and the concomitantly occuring increased 45calcium uptake induced by isoprenaline and tyramine were markedly diminished at the lower pH, the response to tyramine being more affected by increased hydrogen ion concentration than that of isoprenaline. This is possibly due to a decrease in noradrenaline available at pH 7.0 for release by tyramine. Isoprenaline and tyramine enhanced the relative specific 45calcium activity (RSA) without altering the total tissue calcium content. On the contrary, the increase of the extracellular calcium concentration caused an augmentation of the relative specific 45calcium activity and the total tissue calcium content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501847
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  • 5
    Electronic Resource
    Electronic Resource
    Studies on the teratogenic phase specificity of actinomycin D in the rat (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 275 (1972), S. 31-44 
    Details
    ISSN: 1432-1912
    Keywords: Embryonic Development ; Actinomycin D ; DNA-dependent RNA Polymerases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to elucidate the phase specificity of the embryo-lethal and teratogenic action of actinomycin D (day 5–10 of gestation) rats received 3H-actinomycin D at different times of gestation. The distribution of the radioactivity in the fetus and the placenta was measured. Moreover, the effects of actinomycin D on the RNA polymerase reactions in isolated nuclei of the decidual and fetal tissue were studied. The biochemical results were correlated electron microscopically with specific alterations occurring in different structures of the total implantation sites. These studies show that the time-dependent embryo-lethal and teratogenic effects of actinomycin D result from a lesion of the embryo and the decidua. The effects of the decidua occur at an earlier time and are more pronounced as compared to those of the embryo. Since the decidua is significant for the nutrition of the embryo till closure of the yolk-sac and beginning of the yolk-sac circulation (day 10 of gestation), the direct effects of actinomycin D on the embryo are intensified by the lesion of the decidua. After day 10 of gestation till the beginning of the placental function 3H-actinomycin D passes over to the embryo. But the concentration-even after a dose of 1 mg/kg-does not suffice to inhibit in vivo RNA polymerase reactions in isolated nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505066
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  • 6
    Electronic Resource
    Electronic Resource
    Influence of steroid replacement therapy on rat embryos of hypophysectomised mother animals (1971)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 271 (1971), S. 103-110 
    Details
    ISSN: 1432-1912
    Keywords: Embryonic Development ; DNA Polymerase ; Hypophysectomy ; Sex Hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of estrone plus progesterone on embryonic survival were studied in hypophysectomised pregnant rats. Replacement therapy commenced 24 h prior to the ablation of the pituitary which was performed on day 6 of pregnancy. The number of viable fetuses was correlated with increasing amounts of progesterone from 24 to 84 mg/kg given in concert with a constant dose of 4 μg/kg estrone. As judged by the DNA content of the 14-day-old embryos, growth retardation was linked to the reduction of the progesterone levels. No visible malformations were recorded although the experimental period covered the phase of organogenesis. On the other hand, when measuring in isolated nuclei of 14-day-old rat embryos the activity of DNA polymerase, an enzyme the activity of which can be correlated to a certain extent to embryonic growth, it becomes obvious that after treatment with estrone in combination with low (24 or 36 mg/kg) or too high doses (84 mg/kg) of progesterone the correlation between DNA content of the embryos and DNA polymerase activity per cell diverges. This result may point to a cellular malfunction not disclosed by the macroscopic appearance of the embryos at this stage. So it can be concluded that embryonic growth and differentiation processes might be directly dependent on maternal gonadal hormones, at least till day 12 of pregnancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01002175
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  • 7
    Electronic Resource
    Electronic Resource
    Studies on the problem of “aerobic glycolysis” occuring in mammalian embryos (1971)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 268 (1971), S. 235-241 
    Details
    ISSN: 1432-1912
    Keywords: Aerobic Glycolysis ; Embryonic Metabolism ; Glucose Metabolism ; Aerobe Glykolyse ; Stoffwechsel embryonalen Gewebes ; Glucose-Stoffwechsel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01020078
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  • 8
    Electronic Resource
    Electronic Resource
    Bewertung adrenerger β-Receptorenblocker am Kreislauf der Katze (1971)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 270 (1971), S. 79-86 
    Details
    ISSN: 1432-1912
    Keywords: Circulation ; dp/dt max ; Cats ; β-Adrenergic Blocking Drugs ; Isoproterenol Antagonism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In closed-chest cats, anaesthetized with pentobarbital, a comparative study was carried out of the cardiovascular actions of fourβ-receptor blocking agents [propanolol, practolol,d(-) INPEA and LB 46] as well as of their antagonism to the effects of isoproterenol. Theβ-receptor blocking agents were injected intravenously in increasing doses until the positive inotropic action of isoproterenol was abolished. Changes in maximum rate of rise of ventricular pressure (dp/dt max) were taken as a measure of the inotropic action. Heart rate, enddiastolic ventricular pressure, ventricular pressure, arterial pressure and ECG were recorded. The following results were obtained: 1. Propranolol and practolol decreaseddp/dt max to a greater extent than did INPEA, whereas LB 46 in small doses was without effect and at larger doses caused an increase indp/dt max. 2. Propranolol caused a more pronounced decrease in heart rate than did practol or INPEA. Small doses of LB 46 decreased the heart rate, but this decrease was not further enhanced by increasing the dose. 3. Propranolol, practolol and INPEA decreased systolic and diastolic pressure more markedly than did LB 46. 4. The hypotensive action of isoproterenol was antagonized by propranolol, LB 46 or INPEA to a greater extent than its inotropic action; practolol however, had no influence upon the hypotensive action of isoproterenol. 5. The enddiastolic ventricular pressure was not affected by theβ-adrenergic blocking agents, but was significantly enhanced by a subsequent injection of noradrenaline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00997301
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  • 9
    Electronic Resource
    Electronic Resource
    Growth kinetics of mammalian embryos during the stage of differentiation (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 272 (1972), S. 169-181 
    Details
    ISSN: 1432-1912
    Keywords: Embryonic Growth ; DNA ; RNA ; Nuclei
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to get insight into the synthesis rates occuring in mammalian embryos during the phase of differentiation, wet and dry weight as well as DNA-, RNA-, and nitrogen content of the whole implantation site (day 7 to 10 of gestation) and of the embryos (day 11 to 14) have been determined. Growth of the whole implantation site (day 7 to 10) proceeds almost linearly: Within a 24-h period the weight increases about 2-fold. The growth of the embryos, however, is found to be different in each 24-h period between day 8 and 14. All synthesis processes proceed at an extremely rapid rate between day 9 and 12 of gestation. The weight of embryos shows a 6-fold rise between day 11 and 12, the increase being even more pronounced on the preceding days. Growth and increase in cell mass are essentially due to cell division, since DNA content and weight change in a parallel way. Data on the nitrogen content per embryo show that the protein synthesis keeps pace with the rapid cell division. Using pure nuclear fractions isolated from 11- to 14-day-old embryos the average distribution of RNA within the cells can be estimated. The increase in the number of cells within a 24-h period is calculated from the average DNA content per embryo and the average DNA content per nucleus measured in isolated nuclei. The DNA content per nucleus of 12- to 14-day-old rat embryos is found to be almost twice (12±0.5 pg) that of diploid nuclei (6.7–7.2 pg). This inducates that a high percentage of the cells are in the late S-phase or in the G2-phase. The growth rate of the embryos between day 8 and 14 of gestation is calculated from the 24-h rate of increase in cell number which is obtained either biochemically or in the earlier stage of embryonic development with morphological studies. Some peculiarities of the duration of the cell cycle of the rapidly growing tissue are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508767
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  • 10
    Electronic Resource
    Electronic Resource
    Activity of some enzymes of nucleic acid metabolism in developing rat liver (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 274 (1972), S. 385-393 
    Details
    ISSN: 1432-1912
    Keywords: Liver Development ; Thymidine Kinase ; DNA Polymerase ; RNA Polymerases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The increase in DNA, RNA, and nitrogen as well as the activity of some enzymes involved in nucleic acid metabolism were measured during liver development. During the perinatal period (day 18 of gestation until birth) high activities of thymidine kinase and DNA polymerase were found which decline in the early suckling period, whereas the activities of the DNA-dependent RNA polymerases show a slow continuous increase. During the juvenile period (starting about 4 weeks after birth) the values of all enzymes studied approximate to those measured in liver tissue of adult animals. The correlation of these enzymes with the growth kinetics of liver tissue is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501275
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