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Biomedical subjects

L Feuer

Publications and source records attributed to L Feuer.

At least 19 recordsLinked to original sources
PubMed1986

Anticonflict properties of the dipeptide Litoralon and of diazepam in rats.

The anticonflict properties of the anxiolytic diazepam and of the dipeptide Litoralon gamma-L-glutamyl-taurine and two of its analogues SZJ 3388, gamma-aminobutyryl-ethanolamine phosphate, and SZJ 3361, D-1-aminoisobutyrylethanolamine phosphate have been investigated in a "time-to-emerge" conflict paradigm in non-deprived rats. Diazepam, Litoralon and compound SZJ 3388 significantly decreased the "time-to-emerge" latency (TTE latency) in a dose-dependent manner versus saline- or vehicle-treated controls in doses between 0.05 and 0.50 mg/kg intraperitoneally. The analogue SZJ 3361 was inactive as regards the TTE latency, while the anti-histaminic promethazine lengthened the TTE latency in a dose-dependent manner. The number of irresolute responses was significantly decreased following administration of diazepam, SZJ 3388 and Litoralon and was positively correlated with the TEE latency-decreasing activity of these compounds. The data are discussed in terms of the benzodiazepine-like anxiolytic or anti-conflict properties of these dipeptides.

Animals↗
PubMed1986

Inhibition of the formation of protein storage granules by glutaurine in the larval fat body cells of Mamestra brassicae (Insecta, Lepidoptera).

Correlative changes in the protein contents of haemolymph and fat body and the accumulation of protein storage granules in the fat body cells of Mamestra brassicae were investigated during the last larval stage in normally developing larvae and following administration of glutaurine (1 X 10(-4) mg/g body weight). The protein content of the haemolymph of untreated larvae increased up to the 4th day of the stage, declined during days 5 and 6, and increased again before pupation. In the glutaurine-treated larvae the amount of proteins in the haemolymph was as high as in the controls during the first four days but continued to rise up to the end of the stage. The protein content of the fat body started to increase from the 3rd day and heavy accumulation of protein storage granules in the cells of fat body was observed on the 5th and following days. The protein content of the fat body of glutaurine-treated larvae remained at a low level and the protein storage granules were absent in the cells. The inhibition of the selective uptake of haemolymphatic storage proteins by fat body following glutaurine treatment is suggested.

Adipose Tissue↗
PubMed1986

Effect of glutaurine on sleep-wakefulness cycle and aggressive behaviour in the cat.

The effects of glutaurine (gamma-L-glutamyl taurine, Litoralon, Chinoin, Budapest) on the aggressive behaviour and sleep-wakefulness cycle were studied in freely moving cats. Glutaurine, even in doses as low as 0.1 microgram/kg, was found significantly to shorten the latency of the rat-killing reaction elicited by hypothalamic stimulation. On the other hand, the same doses failed to modify the sleep-wakefulness cycle to any significant degree throughout the study period of 4 hours. On the grounds of these and previous data, the possible brain site of the glutaurine action is discussed.

Aggression↗
PubMed1986

Gamma-L-glutamyl-taurine (Litoralon) affects conditioned taste aversion in rats.

The dipeptide gamma-L-glutamyl-taurine (Litoralon) reduced neophobia of rats at a dose of 5.0 mg/kg (i.p.) in a "one-bottle forced choice paradigm" for conditioned taste aversion (CTA), but did not significantly affect the rats' "memory" of intoxication following chronic treatment at doses of 0.05, 0.50 and 5.00 mg/kg (i.p.). Acute treatment with Litoralon (10-1000 micrograms/kg, i.p.) did not affect CTA checked in a "two-bottle test", when administered immediately following the unconditioned stimulus (LiCl injection). In contrast, when given 90 min prior to the retention test, the injection of Litoralon (50.0 micrograms/kg) and gamma-aminobutyryl ethanolamine phosphate (100 and 500 micrograms/kg) resulted in a significantly higher intake of saccharin solution by the rats. This effect is comparable to the action of diazepam tested in the same experimental procedure. The results support our hypothesis about the anti-conflict potencies of these dipeptides, exerted by reducing aversion of phobia and/or the anxiety level of the animals in the experimental situation.

Animals↗
PubMed1985

Effects of Litoralon (gamma-L-glutamyl-taurine) and its analogues on fear-motivated behaviour of rats.

The effects of a single post-trial intraperitoneal administration of the dipeptide Litoralon (gamma-L-glutamyl-taurine) and some of its analogues were tested on the passive avoidance latency of male and female Wistar rats. The avoidance latency was significantly decreased by Litoralon and gamma-aminobutyryl-ethanolamine phosphate but lengthened by DL-beta-aminoisobutyryl-ethanolamine phosphate. No differences were observed between the responses of immature male and female rats following Litoralon treatment. The observed inter-group differences in passive avoidance behaviour following dipeptide administration were also demonstrable in tests of the open-field activity of the animals examined immediately after the 24-hour retention test. The results are discussed on the basis of a central Litoralon effect on emotional arousal and the anti-conflict potencies of the dipeptide.

Animals↗
PubMed1984

Dynamic interactions of evoked potentials in a polysensory cortex of the cat.

Interactions of acoustic and somatosensory evoked potentials were studied in the anterior suprasylvian gyrus of the cat. Two kinds of interaction could be observed: occlusion or facilitation. In most cases occlusion was observed. The interactions showed dynamic changes and were susceptible to different kinds of influences. After having determined the control values of interaction over a period of several minutes, reversible enhancement of occlusion was observed after synchronous activation of the acoustic and somatosensory inputs with 2 Hz frequency. The same effect could be observed during stimulation of the mesencephalic reticular formation with 200 Hz frequency. The interactions could also be influenced by amphetamine and gamma-glutamyltaurine, known as drugs capable of influencing the arousal level of the brain. During treatment with amphetamine the interaction was shifted in the facilitatory direction. The antagonists of amphetamine (haloperidol and reserpine) prevented this effect. The authors suggest that the interactions of acoustic and somatosensory responses are mediated by interneurons (inhibitory and/or excitatory) and particular stimulus situations and drugs are able to modify the equilibrium between excitatory and inhibitory subsystems.

Amphetamine↗
PubMed1983

Glutaurine enhances the depressed NK cell activity of tumor patients.

The effect of glutaurine, a newly discovered parathyroid substance, on human NK cell activity and on lymphocyte markers was studied. Both in vivo and in vitro treatment with glutaurine markedly enhanced the depressed natural lymphocytotoxicity of tumor patients without influencing their lymphocyte subpopulations. On the other hand it had no effect on the NK cell activity of healthy lymphocytes and of tumor patients' lymphocytes with originally "normal" NK activity. The NK-enhancing effect of glutaurine could not be explained by augmentation of the number of potential effector cells. It is suggested that glutaurine increases the originally low spontaneous killer activity of tumor patients' lymphocytes through an indirect regulatory mechanism.

Antineoplastic Agents↗
PubMed1983

Effect of glutaurine on liver tumour development and acute leukaemia induced by MC29 virus in turkey poults.

The effect of glutaurine (gamma-L-glutamyl-taurine, Litoralon) on the take and development of hepatoma and acute leukaemia induced by MC29/L avian oncorna-virus has been investigated in turkey poults. Glutaurine significantly decreased the incidence of hepatoma, but had no significant effect on the lethality of MC29/L infected birds. The number of primitive myeloid cells was lower in the peripheral blood of glutaurine treated birds than in the untreated controls. Reverse transcriptase determinations in turkey fibroblast cell cultures indicated that glutaurine delays MC29/L virus expression.

Animals↗
PubMed1983

Effect of intraventricular administration of glutaurine on norepinephrine, dopamine and serotonin turnover in different brain regions in rats.

The effect of glutaurine (gamma-L-glutamyl-taurine, Litoralon) was studied on dopamine, norepinephrine and serotonin turnover in the hypothalamus, mesencephalon, amygdala, septum, hippocampus, cortex and cerebellum following intracerebroventricular administration. Dopamine and norepinephrine turnover, measured by alpha-methyl-paratyrosine inhibition of catecholamine synthesis, increased in the cerebellum and the norepinephrine turnover in the hypothalamus. Serotonin turnover, measured by serotonin accumulation induced by the MAO inhibitor pargyline, decreased in the mesencephalon. There was no change in catecholamine or serotonin turnover in the amygdala, septum, hippocampus and cortex. The data suggested a highly selective action of glutaurine on brain transmitters in certain brain areas, especially in the cerebellum.

Animals↗
PubMed1981

Formation of gamma-glutamyl-taurine in the rat brain.

After intraventricular administration on 14C- or 3H-labelled taurine, gamma-glutamyl-taurine was detected in the protein free extract of rat brain using a combination of ion exchange chromatography, electrophoretic separation and thin-layer chromatography. Under in vitro conditions gamma-glutamyl-transpeptidase (EC 2.3.2.2.) prepared from rat brain catalyses the formation of gamma-glutamyl-taurine from taurine and glutathione or gamma-glutamyl-p-nitroanilide. The enzymes of the gamma-glutamyl cycle are presumed to be responsible for the in vivo metabolism of this dipeptide.

Animals↗
PubMed1981

Effect of glutaurine and its derivatives and their combinations with radiation protective substances upon irradiated mice.

The radiation protective effects of glutaurine (gamma-L-glutamyl-taurine, Litoralon), and of some of its derivatives, as well as of their combinations with substances of the amino-alkyl-thiol group, have been investigated in mice. The results suggest that glutaurine possesses a radiation protective effect in animals irradiated with LD50/30 of roentgen rays and 60Co gamma rays. The compound has a favourable effect also when administered after irradiation. Its protective effect is especially marked in case of prolonged irradiation. Among the combinations best results were obtained by its simultaneous administration with subminimal doses of AET or cystamine. Some of its derivatives also exhibited considerable protection against irradiation with roentgen rays.

Animals↗
PubMed1981

Effect of treatment with glutaurine on human antibody-dependent cell-mediated cytotoxicity (ADCC).

The effects of in vitro and in vivo treatment with glutaurine, a newly discovered parathyroid hormone possessing immunostimulative activity, on human antibody-dependent cell-mediated cytotoxicity (ADCC) were studied in 15 tumor patients with healthy subjects in a xenogeneic test system using chicken erythrocytes as target cells. A marked increase in "K" cell activity was observed in 8 tumor patients with originally low cytotoxic capacity, while originally normal ADCC activity of other tumor patients and healthy subjects was not significantly influenced by glutaurine treatment. The changes in cytotoxicity were not accompanied by changes in lymphocyte populations. Incubation of effector cells with glutaurine in vitro caused no change in ADCC activity in lymphocyte populations. Some similarities between the effects of glutaurine treatment of ADCC and that of dialyzable leukocyte extracts are discussed.

Adult↗
PubMed1981

Effect of protein-free parathyroid extract (PF-PTE) and gamma-L-glutamyl-taurine (glutaurine) on X-ray induced hyperglycaemia in the rat.

The protein-free parathyroid extract (PF-PTE) and gamma-L-glutamyl-taurine (glutaurine) produced mild hypoglycaemia in rats. Treatment with PF-PTE or glutaurine prevented the development of hyperglycaemia induced by X-ray whole body irradiation with 154.8 or 219.3 or 258.0 mC/kg doses. The plasma IRI values did not change following treatment. It is supposed that glutaurine acts by its antagonistic effect on glucocorticoids but its regenerating effect on the intestinal mucosa cannot be excluded either.

Animals↗