[Effect of picrotoxin on the Cl-activated ATPase microsomal fraction of bream brain (Abramis brama L.)].
It is found that picrotoxine in range concentrations 0.1-10 microM stimulates the basal Mg(2+)-ATPase from microsomal fraction of fish bream (Abramis brama L.), however decreases activating effect of 10(-5) M GABA on the enzyme. The stimulative effect of picrotoxine dependants on duration of preincubation with microsomes. It was established that basal Mg(2+)-ATP-ase activity was activated by anions (Cl- > Br- > I-). The activated effect of anions on the Mg(2+)-ATP-ase is decreased in the presence 1 microM picrotoxine. It was shown that in the dependence on concentration of the Mg(2+)-ATP (0.2 or 1 mM) in the incubation medium the picrotoxine serves as on activator or inhibitor of the enzyme activity. It is supposed that picrotoxine allosterially influences on the enzyme by the receptor-dependent way.
Menzikov
S A
SA
Papanin Institute of Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Region, 152742. sam@ibiw.yaroslavl.ru
Menzikova
O V
OV
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002712:Chlorides / Q000378:metabolism*; D004789:Enzyme Activation; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology*; D010852:Picrotoxin / Q000494:pharmacology*; D021541:Sea Bream; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D000251:Adenosine Triphosphatases; D002712:Chlorides; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid