Formation of Y-aminobutyric acid [GABA] from putrescine in the hypothalami of rats and its possible role as a neurotransmitter

ABSTRACT

Slices prepared from hypothalami removed from male Wistar-derived rats were shown to release 14alpa C alpha [14C GABA] formed from 14C putrescine. The tissue was incubated in Krebs-bicarbonale buffer containing 11 mM glucose. 14C GABA was separated from 14C putrescine by ion-exchange chromatography. In pulse-label experiments highest number of cpm associated with 14C GABA as well as with 14C putrescine were found immediately on removal the latter campound from the incubation medium, thereafter the cpm for both generally kept decreasing was stimulated with 48 M K+, the release of 14C GABA formed 14C putrescine was increased in the but not in the absence of the latter cation, suggesting the possibility that GABA derived front putrescine may have a role as a neurotransmitter. 7-hat the material released was truly 14C GABA was confirmed by performing high voltage paper electrophoresis at a pH of 3.4 and 6.5 with GABA, putrescine and N-monoacetylputrescine as markers