Effect of gabaculine on metabolism and release of γ-aminobutyric acid in synaptosomes

Abstract

Synaptosomes isolated from mouse brain were incubated with [14C]glutamate and [3H]γ-aminobutyric acid ([3H]GABA), and then [14C]GABA (newly synthesized GABA) and [3H]GABA (newly captured GABA) in the synaptosomes were analysed. (1) the [3H]GABA was rapidly degraded in the synaptosomes, (2) when the synaptosomes were treated with gabaculine (a potent inhibitor of GABA aminotransferase), the degradation of [3H]GABA was strongly inhibited, (3) the gabaculine treatment brough about a significant increase in Ca2+-independent release of [3H]GABA with no effect on Ca2+-dependent release, (4) no effects of gabaculine on degradation and release of [14C]GABA were observed. The results indicate that there are at least two pools of GABA in synaptosomes and support the possibilities that GABA taken up into a pool which is under the influence of GABA aminotransferase is released Ca2+-independently and that GABA synthesized in another pool which is not under the influence of GABA aminotransferase is released Ca2+-dependently.

DOI: 10.1007/BF00968675

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Cite this paper

@article{Asakura2004EffectOG, title={Effect of gabaculine on metabolism and release of γ-aminobutyric acid in synaptosomes}, author={Tadashi Asakura and Makoto Matsuda}, journal={Neurochemical Research}, year={2004}, volume={15}, pages={295-300} }