Inhibition of rat brain microsomal Na+/K(+)-ATPase and ouabain binding by mercuric chloride.
This study concerned the effects of mercuric chloride on Na+/K(+)-ATPase and [3H]ouabain binding in rat brain microsomes in vitro. The data showed that HgCl2 inhibited Na+/K(+)-ATPase effectively at micromolar concentrations. The degree of inhibition was decreased with increases in enzyme concentration and incubation time. Variations in the ionic strength of Na+ and K+ did not alter the percent inhibition of Na+/K(+)-ATPase activity by HgCl2. Repeated washings partially restored enzyme activity. The binding of [3H]ouabain to microsomal membranes was inhibited by HgCl2 in a concentration-dependent manner. Cumulative inhibition studies with HgCl2 and ouabain indicated that these inhibitors did not act concurrently and independently on Na+/K(+)-ATPase.
Chetty
C S
CS
Department of Natural Sciences, Selma University, AL 36701.
Rajanna
B
B
Rajanna
S
S
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D008627:Mercuric Chloride / Q000633:toxicity*; D008861:Microsomes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010042:Ouabain / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013997:Time Factors
D008627:Mercuric Chloride; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase