Effect of GABAergic compounds on the anion-sensitive Mg2+-ATPase from bream (Abramis brama L.) brain.
Preincubation of plasma membranes from bream brain with 10-8-10-4 M gamma-aminobutyric acid (GABA) or muscimol increased the anion-sensitive Mg2+-ATPase activity. The activating effect of neurotransmitters on the Mg2+-ATPase is enhanced with increasing preincubation time of the membranes with the ligands, decreases with increasing Mg2+-ATP concentration in the incubation medium, and is inhibited in the presence of the GABAa-receptor antagonist, bicuculline (90 microgr;M). The anions Cl-, Br-, and I- stimulate the basal Mg2+-ATPase activity, and an effect of 10-4 M GABA in the presence of anions was not found. It is supposed that GABAergic chemicals modify the anion-sensitive Mg2+-ATPase in a receptor-dependent way.
Menzikov
S A
SA
Papanin Institute of Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Region. sam@ibiw.yaroslavl.ru
Menzikova
O V
OV
D000818:Animals; D000838:Anions; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000494:pharmacology*; D005399:Fishes; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000494:pharmacology*
D000838:Anions; D020536:Enzyme Activators; D005680:gamma-Aminobutyric Acid; D017301:Ca(2+) Mg(2+)-ATPase