共查询到20条相似文献,搜索用时 0 毫秒
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Abstract— A method is described to evaluate simultaneously the contributions of 2-oxoglutarate oxidation and the GABA bypath to succinate production in isolated rat brain mitochondria.
2-Oxoglutarate oxidation is under respiratory control whereas the activity of the GABA shunt is but slightly affected by the mitochondrial energy state.
The oxidation of GABA is half-maximal with 5m m -GABA. GABA does not affect 2-oxoglutarate oxidation. 1 m m -2-oxoglutarate is optimal for GABA oxidation, whereas higher concentrations inhibit the shunt activity.
The rate of GABA oxidation observed in vitro (5 nmol/min.mg mitochondrial protein) is comparable to the activity of the shunt under in viuo conditions.
The control and the compartmentation of GABA oxidation are discussed. 相似文献
2-Oxoglutarate oxidation is under respiratory control whereas the activity of the GABA shunt is but slightly affected by the mitochondrial energy state.
The oxidation of GABA is half-maximal with 5m m -GABA. GABA does not affect 2-oxoglutarate oxidation. 1 m m -2-oxoglutarate is optimal for GABA oxidation, whereas higher concentrations inhibit the shunt activity.
The rate of GABA oxidation observed in vitro (5 nmol/min.mg mitochondrial protein) is comparable to the activity of the shunt under in viuo conditions.
The control and the compartmentation of GABA oxidation are discussed. 相似文献
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3-METHOXY-4-HYDROXYPHENYLETHANOL IN THE RAT BRAIN 总被引:1,自引:0,他引:1
C. Braestrup 《Journal of neurochemistry》1973,20(2):519-527
Abstract— The neutral dopamine metabolite, 3-methoxy4hydroxypenylethanol (MOPET) can be measured in the rat brain by a GLC method using a pentaflouropropionic derivative and electron capture detector. The identity of MOPET is verified by mass spectrographic analyses.
The endogenous level of MOPET of 16.6 ng/g whole rat brain can be raised more than four-fold by intraperitoneal injection of L-DOPA, dopamine or MOPET. In contrast intraventricular injection of dopamine or intraperitoneal injection of L-DOPA plus a peripheral decarboxylase inhibitor (Ro 4-4602)., results in small and insignificant increase bf MOPET in the CNS.
It is concluded that MOPET is probably of low significance to central dopamine metabolism and that MOPET found in the rat brain is predominantly of peripheral origin. 相似文献
The endogenous level of MOPET of 16.6 ng/g whole rat brain can be raised more than four-fold by intraperitoneal injection of L-DOPA, dopamine or MOPET. In contrast intraventricular injection of dopamine or intraperitoneal injection of L-DOPA plus a peripheral decarboxylase inhibitor (Ro 4-4602)., results in small and insignificant increase bf MOPET in the CNS.
It is concluded that MOPET is probably of low significance to central dopamine metabolism and that MOPET found in the rat brain is predominantly of peripheral origin. 相似文献
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Reynolds CE 《California State Journal of Medicine》1923,21(3):106-109
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METABOLIC COMPARTMENTATION OF GLUTAMATE ASSOCIATED WITH THE FORMATION OF γ-AMINOBUTYRATE 总被引:7,自引:7,他引:0
Abstract— The distibution of 14 C in the brains of rats that had been given [U-14 C]glucose (10μCi/100g body wt.) at 10 min before death was followed for 20 min post mortem. The results indicated that the input of glucose-carbon into the tricarboxylic acid cycle stopped instantaneously after death. Although the proportion (more than 40 per cent) of tissue-14 C combined in the amino acids associated with the cycle did not change significantly, there was a characteristic redistribution of 14 C within the amino acid fraction after death: significantly, the 14 C content of glutamate decreased andthat of GABA increased. The GABA/glutamate specific radioactivity ratio which in vivo was 0-58, increased progressively in the first 5 min after death, reaching a value of 0-93. However, by 5 min the rise in the ratio stopped abruptly, although GABA accumulation continued at about half the initial rate beyond that time. These results indicated that GA BA formation is compartmented in the brain andpermitted the evaluation of certain kinetic parameters of the two compartments which could be distinguished under the experimental conditions. One of the compartments was evidently a summation of a number of subcompartments which had certain features in common, such as a low GABA flux relative to the amount of glutamate. The properties of the other compartment were compatible with those of nerve terminals functioning with GABA as the transmitter. This compartment contained about 2 per cent of the total glutamate, but the glutamate pool was labelled about three times more than the average. Further, this compartment accounted for about 50 per cent of the total GABA formation flux andcontained GABA in high concentrations (the probable values were about seven times the mean). 相似文献
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Cecil E. Reynolds 《The Western journal of medicine》1923,21(3):106-109
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徐立新 《中国应用生理学杂志》2000,16(2):191-192
目的:介绍一种同时进行4路流体灌流的多孔脑片浴槽。方法:用大鼠朋脑皮层脑片细胞外电极记录,观察自发性癫痫样放电。结果:通过染料试验证明4路液体互不通连。用无Mg^2+和含30μmol/L4-氨基吡喧的人工脑脊液灌流1h后,各孔脑片均可出现自发性放电,并可维持稳定达3h以上。结论:此装置可以同时观察4种抗癫痫药物对脑片自发放电的抑制作用。 相似文献
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K. P. Wong 《Journal of neurochemistry》1975,24(5):1059-1063
—3-Methoxy-4-hydroxyphenylglycol (MHPG) formed a sulphate conjugate when incubated with ATP, Mg2+ ions, Na235SO4 and the high-speed supernatant preparations of rabbit or rat brain. The same reactions could be catalysed by similar enzyme preparations from liver. The sulphated product was separated and identified by paper chromatography. On acid hydrolysis, it released both Na235SO4 and the free glycol. The measurement of this labelled sulphate was used as a specific assay procedure for determining the overall sulphoconjugatory process. The pH optimum of the reaction is 7.8. For rabbit brain, the Km for Na2SO4 determined for the activating system is 3.6 × 10−4m , and that for MHPG for the sulphotransferase reaction is 1.05 × 10−4m . The specific enzyme activity, expressed as nmol 35SO4 incorporated/h/mg protein for a 30-min assay is as follows: rat brain, 2.8; rabbit brain, 1.6; rat liver, 33.4and rabbit liver, 15.0. Dithiothreitol at 3 mm concentration had no significant effect on the sulphation of MHPG in all these preparations. 相似文献
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PINNIPED BRAIN SIZES 总被引:1,自引:0,他引:1
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