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  • 1975-1979  (12)
  • 1
    Digitale Medien
    Digitale Medien
    EFFECTS OF X-IRRADIATION INDUCED LOSS OF CEREBELLAR GRANULE CELLS ON THE SYNAPTOSOMAL LEVELS AND THE HIGH AFFINITY UPTAKE OF AMINO ACIDS (1979)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 32 (1979), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract— Crude synaptosomal (P2) preparations were obtained from the cerebella of rats in which the granule cell population had been selectively reduced by X-irradiation treatment and from the cerebella of control animals. In the P2 fraction from control cerebella, the level of glutamate was greater than any other of the 5 amino acids measured and was 2-fold higher than taurine, which was present at the next highest level. The content of taurine was slightly higher than that found for aspartate and was 3-fold greater than that observed for GABA. Alanine and glycine were present in the lowest amounts. The levels of glutamate and aspartate were significantly (P 〈 0.05) lower by 25 and 15%, respectively, in the P2 fraction isolated from the X-irradiated cerebella in comparison to control values. The content of taurine, GABA, glycine, and alanine were not changed by the X-irradiation treatment. The uptake of 1.0 μm-l-[3H]glutamate and l-[3H]aspartate was reduced approx 20% by X-irradiation treatment, whereas the uptake of 1.0 μm-[3H]GABA and [3H]taurine was unchanged. A more detailed kinetic analysis of l-[3H]glutamate uptake revealed there was a 20% decrease in the Vmax value with X-irradiation treatment and no change in the apparent Km value.In a second study, the uptake of l-[3H]glutamate, l-[3H]aspartate and [3H]GABA was measured using P2 fractions obtained from the cerebella of rats in which the population of granule, stellate and basket cells had been reduced by X-irradiation treatment. The uptake of 1.0μm-l-[3H]glutamate, l-[3H]aspartate and [3H]GABA was significantly (P 〈 0.05) reduced to 57, 68, and 59%, respectively, of control values. A more detailed kinetic analysis of [3H]GABA uptake revealed no significant change in the apparent Km and a 35% decrease in the Vmax value.The data are discussed in terms of glutamate being the excitatory neurotransmitter released from granule cells and GABA being the inhibitory neurotransmitter released from basket cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1979.tb11081.x
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  • 2
    Digitale Medien
    Digitale Medien
    NEUROCHEMICAL CORRELATES OF BEHAVIOR (1976)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 27 (1976), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract— Pigeons working on a multiple fixed ratio 50, fixed interval 10 schedule for food reinforcement were killed at 0, 50, 90, 150 and 240 min after an i.m. injection of 300mg/kg l-tryptophan. The levels of tryptophan, 5-hydroxytryptophan, 5-hydroxytryptamine, 5-hydroxyindole acetic acid, tyrosine, dopamine and norepinephrine were concurrently measured in crude nerve ending fractions (P2) isolated from the telencephalon, diencephalon plus mesencephalon and pons plus medulla-oblongata of each pigeon. Increases in 5-hydroxytryptamine levels in the nerve ending fraction from the telencephalon were correlated with the onset of the decreased response rates, whereas a return to baseline responding was correlated with a return to normal serotonin levels in this fraction. Changes in dopamine or norepinephrine were not related to the onset of or recovery from the decreased response rate. One group of pigeons were found which did not display any behavioral disruption even though each had received an injection of l-tryptophan; the content of 5-hydroxytryptophan, 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in the nerve ending fraction isolated from the telencephalon of these birds did not differ from control values.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1976.tb10403.x
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  • 3
    Digitale Medien
    Digitale Medien
    CONTENTS OF SEVERAL AMINO ACIDS IN THE CEREBELLUM, BRAIN STEM AND CEREBRUM OF THE ‘STAGGERER’, ‘WEAVER’ AND ‘NERVOUS’ NEUROLOGICALLY MUTANT MICE (1976)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 26 (1976), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The content of glutamate, GABA, aspartate, glycine and alanine was determined in the cerebellum, brain stem and cerebrum of three different mutant mice which have been named ‘staggerer’, ‘weaver’ and ‘nervous’ on the basis of neurological symptoms. In the ‘staggerer’ and ‘weaver’ mutants there is an almost complete absence of granule cells in the cerebellar cortex while in the ‘nervous’ mutant there is a loss of Purkinje cells (and to a lesser extent a loss of granule cells) in the cerebellar cortex. In the cerebellum of the ‘weaver’ mutant, the content of glutamate was signficantly lower (P 〈 0.025) than control values (8.77 ± 0.76 vs 12.0 ± 1.3 μmol/g tissue wet wt) and the contents of GABA and glycine were significantly greater than normal levels. In the cerebellum of the ‘staggerer’ mutant, the content of glutamate was significantly lower (6.62 ± 0.70 μmol/g) and the contents of glycine and alanine significantly higher than control values. In the cerebrum and brain stem regions of the staggerer mutant, weaver mutant and the normals the contents of the five amino acids were the same. The contents of glycine and alanine in the cerebellum, GARA and glycine in the brain stem and GABA and alanine in the cerebrum of the nervous mutants were higher than control values. The data are discussed in terms of a possible role for glutamate functioning as an excitatory transmitter when released from the cerebellar granule cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1976.tb06466.x
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  • 4
    Digitale Medien
    Digitale Medien
    THE EFFECTS OF INJECTIONS OF d,l-5-HYDROXY-TRYPTOPHAN ON THE EFFLUX OF ENDOGENOUS SEROTONIN AND 5-HYDROXYINDOLEACETIC ACID FROM A SYNAPTOSOMAL FRACTION (1977)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 28 (1977), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract— The effects of i.p. injections of SO mg/kg d,l-5-hydroxytryptophan (5-HTP) and saline alone on the in uitro release of endogenous serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were studied using preparations of axon terminals (P2 isolated from the telencephalon of rats. The level of 5-HT was 2-fold greater and the level of 5-HIAA was 5-fold greater in the P2 fraction isolated from rats given the d,l-5-HTP injection than from rats given saline injections. At 37°C the in vitro efflux of 5-HT and 5-HIAA from the P2 fractions of animals injected with 5-HTP 30min before killing was approx 3 times higher than the saline control group. The amount of 5-HT and 5-HIAA released at 37°C was 3–5 times higher than the amount released at 0°C for both the 5-HTP and saline injected rats. Increasing the concentration of potassium ions in the media to 55 mm significantly increased the release of 5-HT but not 5-HIAA in both groups of animals. The amount of 5-HT released by 55mm-K+ was about 2-fold higher from the P2 fraction isolated from rats given 5-HTP injections with respect to those given saline injections. The potassium stimulated release of 5-HT was calcium dependent. The data thus indicate that injection of 50 mg/kg d,l-5-HTP in rats can cause an increase in the level of 5-HT and 5-HIAA in a crude synaptosomal fraction and that as a result of this increase, there is a temperature dependent increased release of 5-HT and 5-HIAA under normal resting membrane conditions. There is also an increased release of 5-HT as a result of membrane depolarizing conditions induced by elevated potassium levels which is calcium dependent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1977.tb10625.x
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  • 5
    Digitale Medien
    Digitale Medien
    EFFECTS OF TRYPTOPHAN ON SEROTONIN IN NERVE ENDINGS (1976)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 26 (1976), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: —Preparations of crude synaptosome fractions (P2) from the telencephalon and from the diencephalon plus optic lobes of the pigeon and from the telencephalon of the rat were used to study the effects of l-tryptophan on (a) the levels of serotonin (5-HT), norepinephrinc (NE) and dopamine in nerve endings and (b) the release of radioactive 5-HT, NE and dopamine from nerve endings. The level of 5-HT was significantly higher (P 〈 0–05) in the P2 fraction isolated from the telencephalon of pigeons given intramuscular injections of 300mg/kg of l-tryptophan in comparison to control values (1.11 ± 0.09 vs 0.74 ± 0.13 nmol/g original tissue wt). A smaller but not statistically significant increase in 5-HT was noted in the P2 fractions isolated from the diencephalon plus optic lobes of pigeons given injections of l-tryptophan. In vitro studies using preparations of synaptosomes (from both pigeon and rat) labelled with [3H]5–HT demonstrated that 1.0 mm-l-tryptophan caused a 30% increase (P 〈 0.05) in the release of [3H]5-HT over control values. This effect by l-tryptophan was blocked when a decarboxylase inhibitor was added to the medium. Tryptophan had no effect on the levels of NE or dopamine in these nerve endings nor did it have any effect on the release of these two amines from these preparations of synaptosomes. The results are discussed in terms of the role of serotonin in producing depression in pigeons working on a certain learned behavioural task.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1976.tb04454.x
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  • 6
    Digitale Medien
    Digitale Medien
    Tumor-associated immunoglobulins, antitumor antibodies, and antiviral antibodies in C. parvum-treated normal and tumor-bearing mice (1978)
    Springer
    Cancer immunology immunotherapy 5 (1978), S. 141-143 
    Details
    ISSN: 1432-0851
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The administration of C. parvum to mice bearing a transplanted syngeneic MC-induced fibrosarcoma resulted in a significant increase in tumor-associated immunoglobulin levels. The increase was most apparent in the IgA class, though significant increases were noted on occasion in the IgM class and certain IgG subclasses. In contrast, the C. parvum treatment used failed to induce antibody to AKR-type murine leukemia virus envelope components in either normal or tumor-bearing mice.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00199988
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  • 7
    Digitale Medien
    Digitale Medien
    The disposition kinetics of diazepam in pregnant women at parturition (1978)
    Springer
    European journal of clinical pharmacology 13 (1978), S. 275-284 
    Details
    ISSN: 1432-1041
    Schlagwort(e): Diazepam ; pharmacokinetics ; pregnant women ; plasma clearance ; blood/plasma concentration ratio ; placental transfer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The disposition of diazepam has been studied in pregnant women at parturition. The plasma concentration of diazepam was monitored for at least 3 days in 18 women who received a single intravenous injection of 10 mg during the 10 h-period prior to delivery. Fourteen mothers had uneventful puerperia (Group I) and in 13 of these cases there was a pronounced postnatal increase in the plasma concentration of diazepam. The terminal phase half-life (t1/2) was significantly greater for Group I (mean = 65 h; range = 24–114 h) than for age-matched non-pregnant patients (mean = 29 h; range = 18–44 h from literature). The prolonged t1/2 appeared to be related to changes in the distribution of diazepam and not to a reduction in hepatic elimination since the total plasma clearance (Cltp) in these 14 pregnant patients (mean = 28 ml/min; range = 18–43 ml/min) was not reduced compared to that reported for non-pregnant controls (mean = 30 ml/min; range = 22–45 ml/min). Four mothers underwent postnatal surgery for tubal ligation (Group II) and the plasma concentration-time profiles for this group did not show the same postnatal phenomenon as did the profiles obtained for Group I. The t1/2 for Group II was shorter (mean = 31 h; range = 24–37 h) than for Group I and similar to that for the non-pregnant controls. The Cltp for Group II was greater (mean = 56 ml/min; range = 48–63 ml/min) than for both Group I and non-pregnant controls. These results suggest that delivery alters the disposition of diazepam and is generally associated with a postnatal re-distribution of diazepam into the systemic circulation. The blood/plasma concentration ratio was determined in 9 patients (mean = 0.62; range = 0.54–0.77). There was no difference in the total blood clearance between the pregnant patients of Group I and the non-pregnant controls. In most cases the umbilical venous plasma concentration (Cpuv) of diazepam was greater than the peripheral maternal venous plasma concentration (Cpmv) at delivery. The foetus appears to constitute a slowly equilibrating tissue-group in which diazepam does not reach equilibrium with the maternal systemic circulation for at least 5–10 h at which time the diazepam concentration in maternal and foetal plasma is similar.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00716363
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  • 8
    Digitale Medien
    Digitale Medien
    Ultrastructural changes in the dorsal root ganglia evoked by thalidomide in rabbits (1976)
    Springer
    Cellular and molecular life sciences 32 (1976), S. 597-599 
    Details
    ISSN: 1420-9071
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Administration of the teratogenic drug thalidomide to pregnant does produces ultrastructural changes in foetal ganglion cells, Schwann cells and axons in the posterior root ganglia corresponding to forelimb segments deformed by the drug. Ultrasttructural changes in ganglia appear on the 13th day of gestation, i.e., preceding the appearance of limb malformation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01990184
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  • 9
    Digitale Medien
    Digitale Medien
    Effects of selective doses of x-irradiation on the levels of several amino acids in the cerebellum of the rat (1976)
    Springer
    Neurochemical research 1 (1976), S. 141-152 
    Details
    ISSN: 1573-6903
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The cerebella of rats were exposed to selective doses of low levels of x-irradiation beginning on day 4, 8, or 12 following birth. The doses of x-irradiation given on days 12, 13, and 15 (12–15X group) resulted in a 24% reduction in the wet weight of the cerebella; the doses given on days 8, 9, 11, 13, and 15 (8–15X group) resulted in a 57% weight reduction; the doses given on days 4, 5, 7, 9, 11, 13, and 15 (4–15X group) resulted in a 67% weight reduction. The schedule of x-irradiation begun on day 12, which prevented the acquisition of the late-forming granule cells, reduced the levels (nmole/mg dry tissue weight) of alanine (22%) and glutamate (10%), and increased the levels of glycine (15%), GABA (13%), and taurine (71%), with respect to control values. The schedule begun on day 8, which prevented the acquisition of stellate and granule cells, reduced the levels of alanine (15%), glutamate (12%), and taurine (21%), and increased the levels of glycine (102%) and GABA (56%). The schedule begun on day 4, which prevented the acquisition of basket, stellate, and granule cells, reduced the level of glutamate (15%) and increased the levels of glycine (186%) and GABA (78%). The levels of alanine and taurine in the cerebella of the 4–15X group were the same as control values. The level of aspartate in the cerebella of the 3 groups of x-irradiated animals was not significantly different from control values. The consistent reduction in the level of glutamate as a function of the number of doses of x-irradiation is suggestive that glutamate may have a higher level in the granule cells than in other cells in the cerebellum, and that the higher level may be a reflection of a possible excitatory transmitter role for glutamate. In addition, the data are interpreted in terms of taurine being associated with the stellate cells and possibly serving as a transmitter for these inhibitory interneurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00966106
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  • 10
    Digitale Medien
    Digitale Medien
    Release of serotonin from nerve endings byl-5-hydroxytryptophan,α-methyl-m-tyramine, and elevated potassium ions (1976)
    Springer
    Neurochemical research 1 (1976), S. 233-249 
    Details
    ISSN: 1573-6903
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The release of [3H]5-hydroxytryptamine ([3H]5-HT) byl-5-hydroxytryptophan (L-5-HTP),α-methyl-m-tyramine (α-MMTA), and elevated levels of K+ was studied using crude synaptosomal preparations (P2) isolated from the telencephalon of the rat and pigeon. Studies were conducted in vitro in the presence of either 2×10−5 M tranylcypromine, which inhibited the MAO activity of both the extrasynaptosomal mitochondria and the mitochondria contained within the nerve endings (intrasynaptosomal mitochondria), or 2×10−5 M nialamide, which inhibited the MAO activity of the extrasynaptosomal mitochondria under the experimental conditions used. In the P2 fraction isolated from the rat, either 55 mM K+, 0.10 mMl-5-HTP, or 0.03 mMα-MMTA significantly increased the release of [3H]5-HT above control levels, regardless of which MAO inhibitor was present in the medium. In the presence of tranylcypromine, this increased release by 55 mM K+ or 0.10 mMl-5-HTP was partially suppressed if Ca2+ was omitted from the medium. In the presence of nialamide, the release by 55 mM K+ was completely prevented if Ca2+ was omitted; the release byl-5-HTP was only partially affected. The release of [3H]5-HT byα-MMTA did not appear to be markedly affected by removal of Ca2+, regardless of which MAO inhibitor was present. Very similar data were obtained in the presence of nialamide using the P2 fraction isolated from the telencephalon of the pigeon, with the exception that 0.10 mMl-5-HTP caused an increase in the release of [3H]5-HIAA (which was not calcium-dependent) instead of [3H]5-HT. The data are discussed in
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00973771
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