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1.
Summary Repeated oral administration of cannabis extract as well as synthetic 9-tetrahydrocannabinol to male rats produced significant changes in excretion of androgenic steroids and their metabolites as detectable in blood and urine. Cannabis extracts were found to be significantly more active than the mixtures containing same amounts of synthetic cannabinoids.Acknowledgment. This work was supported by Grant No. R01-DA-00507 from the National Institute on Drug Abuse, US Public Health Service.  相似文献   

2.
Summary Small doses of vasopressin (200 U min–1 kg–1) did not influence the loss of ability of acutely hypophysectomized rats to react by natriuresis to the extracellular fluid volume expansion with saline, inspite of restoring their arterial blood pressure to normal. It is concluded that the level of antidiuretic hormone efficient enough to concentrate urine is not a decisive factor in the homeostatic mechanism promoting the volume natriuresis.Acknowledgment. Skilful technical assistance of Mrs E. Blaková is sincerly appreciated.  相似文献   

3.
Summary GABA (6×10–6 M) binding to synaptosome-enriched fractions of cat CNS exhibited a clear rostro-caudal gradient, whereas glycine (6×10–6 M) binding was greatest to particles of cerebellar cortex, and this was followed by medulla caudate nucleus cerebral cortex pons > corona radiata. Strychnine-SO4 (10–3 or 10–4 M) inhibited the binding of GABA and glycine in all brain regions studied; at 10–5 M this drug inhibited the binding of both GABA and glycine only to particles of the cerebral cortex.This study was supported by Centro Nacional Ramón y Cajal and Fundación Juan March. P. M. was a summer student from Eastern Nazarene College, Wollaston, Mass., USA.  相似文献   

4.
Summary High-affinity, Na+-independent binding of -alanine to a synaptosomal fraction of rat brain was potently inhibited by glycine and by some other -amino acids, but not by taurine or GABA. This binding mechanism, which was also sensitive to both bicuculline and strychnine, might involve synaptic receptors for both -alanine and glycine.This study was supported in part by Centro Ramón y Cajal and Fundacion Juan March.  相似文献   

5.
The induction of lymphokine-activated killer (LAK) cells from natural killer (NK) lineage cells by interleukin-4 (IL-4) was studied in vitro. Activation of nude mouse spleen cells by IL-4 generated cytotoxic cells, capable of killing NK-sensitive as well as NK-resistant tumor cells. The induction of peak lytic activity was demonstrated after 3 days of culture with IL-4. Surface marker analysis indicated that the majority of precursor cells were aGM1+, Thy1, and the majority of effector cells were aGM1+, Thy1+, suggesting that IL-4 induced LAK cells from nude mouse spleen cells were similar to those from normal mouse spleen cells. The induction of nude mouse LAK cells by IL-4 was partially inhibited by anti-IL-4 or anti-interferon (IFN)-, antibody, and it was further inhibited by the combination of two antibodies, suggesting that IFN-, production was associated with LAK induction of NK lineage cells by IL-4.  相似文献   

6.
The presence of specific binding sites for phorbol esters was studied in a transformed but non-tumorigenic human urothelial cell line HCV-29 by assay of specific binding of3H-phorbol-12,13-dibutyrate (3H-PDBu) to intact living cells.3H-PDBu bound specifically to HCV-29 cells in a saturable and competitive manner. Scatchard plot analysis of specific binding yielded a curved plot consistent with two binding sites with Kd of 11 nM and 102 nM, respectively. At saturation the corresponding PDBu binding capacities (Bmax) were 8.8 pmol/106 cells (5.2×106 molecules bound per cell) and 2.8 pmol/106 cells (1.7×106 molecules bound per cell).3H-PDBu binding was displaced by biologically active phorbol ester tumor promoters such as 12-O-tetradecanoylphorbol-13-acetate (TPA) and mezerein,but not by tumor promoters such as L-tryptophan, anthranilic acid and sodium saccharin. In cells desensitized by pretreatment with 1 g/ml (2M) TPA or PDBu for 24 h the level of binding was reduced to 28% of the level in non-exposed cells. The ability of desensitized cells to bind3H-PDBu was gradually restored within 5–6 days. At the same time the cells became sensitive to the morphological alteration induced by PDBu. This suggests that desensitization of HCV-29 cells is due to a decreased receptor-ligand binding capacity probably associated with down regulation of the phorbol ester receptors.  相似文献   

7.
Summary Na+, K+-adenosinetriphosphatase (Na+, K+-ATPase) activity was decreased in liver plasma membranes from rats in which cholestasis had been induced by i.v. administration of sodium taurolithocholate (5 moles/100 g b. wt). Incubation of liver plasma membranes with taurolithocholate (10–1300 M) caused significant and dose dependent reductions of Na+, K+-ATPase activity at taurolithocholate concentrations above 100 M. These findings lend support to the hypothesis that cholestasis induced by monohydroxy bile acids is at least partially the result of an inhibition of hepatic Na+, K+-ATPase activity.This work was supported by the Swiss National Science Foundation.The authors thank Mr H. Sägesser and Miss B. Schütz for technical assistance.  相似文献   

8.
An animal unable to synthesize ascorbic acid uniquely minicks human and non-human primates. Therefore, in this study we used the rainbow trout, a teleost fish, as the model animal to study the importance of dietary ascorbic acid on the fertilizing ability of sperm. A high concentration of ascorbic acid in semen plays a key role in maintaining the genetic integrity of sperm cells, by preventing oxidative damage to sperm DNA. This study will show that the concentration of asorbic acid in seminal plasma refelcts the dietary fed either an ascorbate-free diet (from 4.74±0.9 to 0.16±0.08 g ml–1) or an ascorbate-rich diet (from 37.9±4.7 to 17.7± 3.2 g ml–1) during the sperimnation season. The relationship between ascrobate status and fertility was studied in six groups of fish fed graded levels of ascorbic acid, which sperimated over a 150-day-period. Sperm from individual males was used to fertilize several batches of eggs. When the seminal plasma ascorbate concentration decreased to 7.3 g ml–1 a significant decrease of fertilization rate and the hatching rate of embryos resulted. This is the first evidence that dietary ascorbate level directly affected sperm quality and influenced male fertility in a scruvy-prone vertebrate.  相似文献   

9.
Summary 5-Hydroxyhaemopyrrole lactam, the mauve factor reported in the urine of schizophrenics and porphyrics was found to inhibit electrically-stimulated contractions of guinea-pig ileum only at high concentrations (ID50=8.5 mM). This low potency makes it unlikely that the compound can account for neurotoxic effects in human porphyria.We thank the Wellcome Trust for a grant.  相似文献   

10.
Summary Spreading depression (SD) was elicited in rats anesthetized with pentobarbital by a train of 8 electrical pulses (0.1 ms, 10 Hz) applied to parietal cortex. Local application of 50 g of D-ala2-metenkephalinamide (DAME) on the stimulated area evoked one or two SD waves followed by an increase of SD threshold from 40 V to 90 V. This effect could be partly prevented by naloxone (1 mg/kg i.p.) and reversed by local application of 4-aminopyridine (10–3 M, 2 l), which reduced SD threshold to 5 and 20 V in normal and DAME-treated cortex, respectively. It is argued that DAME exerts an inhibitory effect on cortical neurons and that the initial SD facilitation is due to initial blockade of inhibitory neurons in the superficial cortical layers.supported by the European Training Program in Brain and Behavior Research.  相似文献   

11.
Transgenic animal models of sickle cell disease   总被引:2,自引:0,他引:2  
An animal model which allows study of chronic processes occurring in sickle cell disease has finally been realized with the development of several lines of transgenic mice which express high levels of s or s-variants in their red cells. The red cells of all mouse lines exhibit characteristic sickle shapes on deoxygenation and most lines have enlarged spleens and mildly elevated reticulocytes in adult mice; both of these properties are suggestive of enhanced red cell destruction and erythropoiesis. However, all lines examined to date have normal hemoglobin levels in adult mice. In one mouse line under ambient conditions, retinopathy and abnormal renal function have been observed and in the same line under hypoxic conditions, anemia, irreversibly sickled cell formation, and urine concentrating defect have been observed. The current mouse lines will allow some aspects of sickle cell disease to be studied, but sigificant improvements can still be made in the transgenic mouse model.  相似文献   

12.
Summary 2O,6N-butyryl, 3, 5-cyclic monophosphate (dibu cAMP) when added to fetal rat heart cells in culture inhibits myocyte contraction. This inhibition is 100, 84 and 51% complete when the dibu cAMP concentration used is 2, 0.2 and 0.02 mM, respectively. The potency of dibu cAMP derivatives in myocyte contraction inhibition follows the order, dibu cAMP> 6N-bu cAMP> 2O-bu cAMP=AMP>butyrate. The inhibition caused by the first three chemicals is greater than 70%.The author was a Moss Heart Fellow and acknowledges the technical assistance of Ms Martha Peet. This work was supported in part by the American Heart Association, National Science Foundation and American Cancer Society.  相似文献   

13.
Summary Aloenin has been established to be 4-methoxy-6-(2--D-glucopyranosyloxy-4-hydroxy-6-methylphenyl)-2-pyrone; it shows an inhibitory activity for gastric juice secretion. Rats metabolized it to 4-methoxy-6-(2,4-dihydroxy-6-methylphenyl)-2-pyrone, 2,5-dimethyl-7-hydroxychromone and glucose, which were excreted in the feces and the urine. The distribution of the radioactivity originating from14C-labeled aloenin was studied. The tracer found in the kidney and the liver reached 60% of the amount administered 24 h after feeding and decreased rapidly in the next 24 h.  相似文献   

14.
Summary (–)-8-Hydroxymethyl-1-tetrahydrocannabinol (THC)1, a novel analog of 1, is shown to be as active as 1 and twice as active as 1 in the dog ataxia test.Acknowledgment. This work was supported by NIDA (Grant Nos. DA-00574-01 and DA-00490).  相似文献   

15.
Summary The role of interferon (IFN) in controlling chronic infections ofListeria monocytogenes (Listeria) was studied in athymic C57BL/6nu/nu mice, and by treating thymectomized C57BL/6 +/+ mice with monoclonal rat CD4 and CD8-specific monoclonal antibodies (Mab). Mice treated with a combination of the two T cell subset antibodies were similar to athymic, nude mice in being able to contol Listeria infection, keeping the titers below 3–5 log10 bacteria per organ, but they could not eliminate them completely. Treatment with antibodies to IFN of nude or CD4+ + CD8+-T cell-depleted mice suffering from chronic Listeria infection caused a marked increase of Listeria titers, in liver and spleen. This result implies a role of IFN in maintaining anti-Listeria resistance in mice lacking mature T cells.  相似文献   

16.
Summary In order to identify the presence of dibenamine and dibenamine-like compounds in biological substances (urine, sera) bromine cresol purple was used as a formative element in the adduction of dyestuff (i.e. as Farbstoffadduktbildner). This method permits a more simplified and more sensitive process of work than that suggested byBrodie and his collaborators.  相似文献   

17.
Summary Haptoglobin and isoagglutinin were found in the urine of diabetic patients, and their renal excretion was higher in patients with diabetic angiopathy. It is concluded from these results (the biological activity of the two polypeptides in urine was intact) that the mechanism of proteinuria can perhaps be explained only by an extension of pores of the renal glomerular filter.  相似文献   

18.
Summary 1-Tetrahydrocannabinol ( 1-THC) has been quantified directly in erythrocyte membranes from drug-treated mice using gas chromatography/mass spectrometry. Concentrations of approximately 6 ng 1-THC/mg membrane protein (10–5 M) were found when effects of the drug on behavior were prevalent. At these concentrations the drug produced a decrease in membrane order as measured by ESR.This work was supported by grants from the Medical Research Council, the Wellcome Trust and the E. P. Abraham Cephalosporin Trust  相似文献   

19.
Summary 11-hydroxy-epiandrosterone was isolated and identified from urine of normal untreated female guinea pigs. After cold and hot acid hydrolysis of the urine, we found another 3-hydroxy-17-oxosteroid. Its character was investigated by several methods and we suppose this steroid is9(11)-epiandrosterone, an artificial product of 11-hydroxy-epiandrosterone.  相似文献   

20.
Summary Single s.c. injections of 10 or 1000 mg/kg of 9-THC did not induce discernable chromosomal damage but caused significant mitotic inhibition in the bone marrow of Syrian hamsters.Acknowledgments. The authors which to thank Mr R.H. Graham, Department of National Health and Welfare, Health Protection Branch, for the generous supply of 9-THC. This research was supported by a grant to Dr M.G. Joneja from the Department of National Health and Welfare.  相似文献   

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