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1.
Summary The aim of the present investigation was to look for the mechanisms causing disturbances in carbohydrate metabolism during the action of the epileptogenic agent methionine sulfoximine The levels of glucose, glycogen, and indolamines were measured in seven different regions of rat brain. Methionine sulfoximine induced a decrease in serotonin level which was roughly dose-dependent. There were no obvious, changes in tryptophan and 5-hydroxyindoleacetic levels in any area. Methionine sulfoximine induced the known increase in glucose and glycogen levels. The direct precursor of serotonin, 5-hydroxytryptophan, and benserazide (a decarboxylase inhibitor) were then injected into rats in association with methionine sulfoximine. In this case, methionine sulfoximine failed to induce seizures. Moreover, the serotonin level was unchanged and the carbohydrate content did not significantly increase. There was only a rise in 5-hydroxyindoleacetic acid level. This work shows a striking parallelism between serotonin decrease and glycogen increase.  相似文献   

2.
C P Chow  H H Cornish 《Experientia》1979,35(8):1090-1091
This study suggests that replacement of intracellular potassium by rubidium ions might lower the resting membrane potential. Thus rubidium-treated rats were more responsive to depolarizing influences and generated more cyclic AMP in the brainstem and consequently the behavioral changes.  相似文献   

3.
To investigate the properties of the gamma-aminobutyric acid (GABA) synthesizing enzyme, glutamate decarboxylase (GAD), in the brain and the pancreatic islets of the rat, GABA concentration in the brain and the pancreatic islets was measured after intraperitoneal administration of 3-mercaptopropionic acid (3-MP) at 25 mg/kg. 60 min after the administration of 3-MP, GABA concentration in the hypothalamus, the superior colliculus and the hippocampus of the brain decreased by 20–30% and in the pancreatic islets by 35%. The concentration in the pancreatic acini did not change. Western blotting showed that GAD activity in the pancreatic islets decreased after administration of 3-MP compared to the control. The activity of GAD in the pancreatic islets as well as brain can be modified by a convulsant, in this case 3-MP. These results suggest the properties of GAD may be similar in the pancreatic islets and brain.  相似文献   

4.
In pregnant mare's serum gonadotropin (PMS) treated immature rats the cortex, cerebellum, caudate nucleus and hypothalamus were isolated and analyzed for their serotonin (5-HT) content at 6-h intervals for 72 h. Results showed a general trend of significant variation occurring in days 1 and 3 after PMS injection with no major variations observed on the second day. The results obtained suggest a possible involvement of 5-HT in the control of ovulation.  相似文献   

5.
Summary This study suggests that replacement of intracellular potassium by rubidium ions might lower the resting membrane potential. Thus rubidium-treated rats were more responsive to depolarizing influences and generated more cyclic AMP in the brainstem and consequently the behavioral changes.  相似文献   

6.
Summary In neonatal rat brain 6 h after s.c. administration of L-cysteine, an increase was observed in most of the amino acids with the exception of glutamic acid, aspartic acid, phenylalanine, sarcosine, glutamine, hydroxyproline and phosphoethanolamine compared to age-matched saline controls. Cysteine was not present at detectable levels in control brain but was found to be 0.38 to 0.52 mole/g of fresh brain tissue in 2- and 4-day-old rats respectively after cysteine treatment.  相似文献   

7.
Intraventricular injection of 250 microgram of 5 HTP induces both slow wave and paradoxical sleep, after 20-60 min. latencies, in insomniac Cats pretreated with P-chlorophenylalanine. Direct injections of 5 HTP in several brain stem structures do not induce sleep. The long latency or paradoxical sleep induction and its suppression with chloramphenicol suggest that indolamines are not directly responsible for paradoxical sleep, but that they act by controlling the synthesis and/or the liberation in the periventricular system of some specific paradoxical sleep inducing factor.  相似文献   

8.
Caerulein, infused in normal subjects, significantly reduces serum Calcium levels; in addition, when infused 60 or 90 min after radioactive calcium, it increases the specific plasma radioactivity, in a manner similar to calcitonin. These results suggest that in man caerulein stimulates calcitonin release.  相似文献   

9.
10.
P H Wu  K C Moore  J W Phillis 《Experientia》1979,35(7):881-883
Studies on the distribution of ATP in microdissected segments of the rat brain indicate that the nucleotide is concentrated in gray matter, and especially in the thalamus, hippocampus, entorhinal cortex and sensorimotor cortex. These distribution studies in conjunction with previous neuropharmacological studies, support the concept that adenine nucleotides may function as intercellular mediators in various regions of the brain.  相似文献   

11.
S P Mann 《Experientia》1975,31(11):1256-1258
The distribution of glycerylphosphorylcholine diesterase in the rat brain has been examined. The enzyme was evenly distributed throughout the brain but was localized in the synaptosome (nerve ending) fraction which was prepared by ultracentrifugation.  相似文献   

12.
13.
Retinoic acid was administered to hamsters suffering from N-nitroso-N-methylurethane-induced fibrosing alveolitis. A significant increase in macrophage numbers was seen in the lungs of retinoid-treated animals as compared to the unsupplemented group.  相似文献   

14.
15.
A A 2-dimensional thin-layer method has been developed for the separation on cellulose of adenine and guanine derivatives. Using incubated rat cerebral cortex slices it was shown that noradrenaline and acetylcholine stimulated cAMP and cGMP production respectively but glutamate and gamma-aminobutyric acid stimulated production of both cyclic nucleotides.  相似文献   

16.
The effects of various concentrations of ionized Ca were examined on the activity of rat brain tryptophan hydroxylase previously treated with EGTA. Within the range of ionized Ca-concentrations though to be physiologically important (10(-8) to 10(-5) M), no significant activation of the enzyme occurred, although activation was observed at higher concentrations of the metal.  相似文献   

17.
Summary In pregnant mare's serum gonadotropin (PMS) treated immature rats the cortex, cerebellum, caudate nucleus and hypothalamus were isolated and analyzed for their serotonin (5-HT) content at 6-h intervals for 72 h. Results showed a general trend of significant variation occurring in days 1 and 3 after PMS injection with no major variations observed on the second day. The results obtained suggest a possible involvement of 5-HT in the control of ovulation.  相似文献   

18.
A Baba  T Tsukamoto  T Matsuda  H Iwata 《Experientia》1978,34(9):1139-1140
Cyclic AMP phosphodiesterase (PDE) in membrane fraction from rat cerebral cortex was activated by Triton X-100, and treatment at alkaline pH and with phospholipase C. These results suggest that membrane PDE exists in a latent form and is influenced by microenvironmental changes within the membrane. Furthermore, the PDE, unlike soluble enzyme, is not influenced by a protein activator and Ca++.  相似文献   

19.
T Kato  T Hama  T Nagatsu  H Kuzuya  S Sakakibara 《Experientia》1979,35(10):1329-1330
We found X-prolyl dipeptidyl-aminopeptidase activity in rat brain and examined the developmental changes at various ages. The total enzyme activity per brain increased until 4 weeks of age, and then decreased during maturation. Specific activity in young rat brain was higher than that in adult rat brain. The properties of the brain enzyme were different from those of pituitary and other tissues.  相似文献   

20.
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