[Effect of gamma-aminobutyric acid on Mg2+-ATPase of brain microsomes of the fish Abramis brama L].

The influence of the GABA on the Mg(2+)-ATPase from microsomal fraction of fish brain (Abramis brama L.) was investigation. Preincubation of the microsomes with different concentration of GABA (10(-8)-10(-4) M) stimulated Mg(2+)-ATPase activity. This effect of neuromediator is sensitive to picrotoxine (10(-4) M). It was established that Mg(2+)-ATPase activity stimulated by anions (Cl > Br > F), inhibited by SCN- and not effected by HCO3-. The influence of the anions on the Mg(2+)-ATPase is liable to be inhibited by picrotoxine. It was supposed that anion-sensitive Mg(2+)-ATPase is associated functionally with GABAa-receptor.