RESUMO
Unilateral ligation of a common carotid artery in gerbils causes a decreased rate of serotonin synthesis and degradation but an increased release of this monoamine. In the brain, reduction of cerebral serotonin content during ischemia is followed by accumulation of its main metabolite, 5-hydroxyindolacetic acid. These data support the contention that serotonin plays an important role in the progression of cerebral infarction.
Assuntos
Córtex Cerebral/metabolismo , Transtornos Cerebrovasculares/metabolismo , Serotonina/metabolismo , Animais , Córtex Cerebral/efeitos dos fármacos , Fenclonina/farmacologia , Gerbillinae , Ácido Hidroxi-Indolacético/metabolismo , Pargilina/farmacologia , Probenecid/farmacologia , Fatores de TempoRESUMO
Insulin in a dose of 0.5 U ml-1 in the incubation medium did not change ATP and phosphocreatine contents in the isolated rat brain microvessels, when energy production was supported by 5.5 mmol l-1 glucose. However, the entrance of non-metabolizable glucose analogue, 2-deoxy-D-[3H]glucose into the microvessel cells was strongly enhanced, almost 18-fold.
Assuntos
Encéfalo/irrigação sanguínea , Permeabilidade Capilar/efeitos dos fármacos , Glucose/metabolismo , Insulina/farmacologia , Trifosfato de Adenosina/análise , Animais , Barreira Hematoencefálica , Capilares/análise , Desoxiglucose , Masculino , Fosfocreatina/análise , Ratos , Ratos EndogâmicosRESUMO
Treatment of gerbils with 40 mg/kg of pentobarbital (i.p.) reduced the metabolic rate in the hippocampus and cerebral cortex by approximately 60%. However, the depression of metabolic rate was lost within 40 s of ischemia and further, pentobarbital delayed but did not prevent the depletion of energy metabolites observed in the ischemic brain.
Assuntos
Encéfalo/metabolismo , Metabolismo Energético/efeitos dos fármacos , Ataque Isquêmico Transitório/metabolismo , Pentobarbital/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Gerbillinae , Glucose/metabolismo , Glicogênio/metabolismo , Cinética , Masculino , Fosfocreatina/metabolismoRESUMO
Depression is frequently encountered in Parkinson's disease and was seen to occur in 14 of 26 patients studied. The levels of 5-hydroxyindoleacetic acid (5-HIAA), the main metabolite of serotonin (5-HT), in CSF samples of the patients were significantly lower than in those of controls. However, within the group of patients the levels of 5-HIAA in CSF samples were significantly lower in the depressive subgroup compared with the non-depressive patients. Moreover, no correlation was recorded between motor disability and depression. The results indicate that disturbed 5-HT metabolism may possibly play a role in Parkinson's disease as a predisposing factor in the development of depression.
Assuntos
Transtorno Depressivo/líquido cefalorraquidiano , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Doença de Parkinson/líquido cefalorraquidiano , Serotonina/metabolismo , Idoso , Transtorno Depressivo/etiologia , Transtorno Depressivo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Doença de Parkinson/metabolismoRESUMO
Bilateral occlusion of common carotid arteries in Mongolian gerbils was produced for the periods (up to 15 min) which were shown to be totally reversible. There was an initial increase of cyclic AMP and GABA levels and enhanced activities of adenylate cyclase and glutamate decarboxylase, as well as the reduction of norepinephrine level and decreased activities of monoamine oxidase, GABA-transaminase and Na+-K+-ATPase. Following these changes, decreased concentration of dopamine, serotinin and glutamate were found. The activities of total protein kinase and acetylcholinesterase were found to be reduced after longer periods of short-term ischemia. The data are consistent with the concept of increased non-controled release of putative neurotransmitters in ischemia.