COMPARISON OF THE BINDING’ OF β‐ALANINE AND y‐AMINOBUTYRIC ACID IN SYNAPTOSOMAL‐MITOCHONDRIAL FRACTIONS OF RAT BRAIN¹

Abstract

Abstract— Na + ‐dependent ‘binding’ of β‐alanine and GABA was examined with synaptosomal‐mitochondrial fractions of rat brain incubated for 10 min at 0°C. GABA was bound to a much greater extent than β‐alanine to particles of cerebral cortex, whole cerebellum and brain stem. For cerebral cortex, the binding capacity ( B max ) for GABA was about 18 limes greater than that for β‐alanine. and the affinity of the particles for GABA was about 2′ times greater than for β‐alanine. The order of potency of GABA binding to brain regions was cerebral cortex > cerebellum > brain stem, whereas that for β‐alanine was the reverse. If the binding of β‐alanine is taken to indicate the glial component of the Na + ‐dependent binding process for GABA, then most of the GABA was bound to neuronal elements under the conditions employed.