UPTAKE OF GAMMA-AMINOBUTYRIC-ACID BY MITOCHONDRIAL AND SYNAPTOSOMAL FRACTIONS FROM MOUSE BRAIN

The accumulation of γ-amino[14C]butyric acid ([14C]GABA) by purified nerve ending particles (synaptosomes) and mitochondria of mouse brain was investigated in the presence of aminooxyacetic acid, which prevents metabolic degradation of GABA. The accumulation of GABA by synaptosomes and brain mitochondria was Na+ dependent and involved both energy independent and dependent accumulation processes. Pyruvate and glucose stimulated synaptosomal GABA accumulation at 30°C and that of mitochondria was stimulated by pyruvate and not by glucose. 2,4-Dinitrophenol, ouabain and malonate inhibited energy dependent accumulation of GABA by synaptosomes and brain mitochondria, and iodoacetate only affected the glucose stimulated synaptosomal uptake of GABA at 30°C. Results were presented which demonstrate a marked time dependent loss of uptake capacity by the subcellular fractions. A rapid procedure for obtaining a functionally superior mitochondrial fraction was described. © 1969.