Effects of metal ions on plasma membrane Mg2+-atpase in rat uterus and ovaries.
The in vitro effects of cadmium and mercury were investigated on the Mg(2+)-ATPase activity of plasma membranes from the rat ovary and uterus. ATP hydrolyzing activities were significant and dose-dependent-inhibited in both plasma membrane preparations by both metals. According to the IC(50) and apparent K(i), Cd(2+) was most potent in the ovary, while Hg(2+) was most potent in the uterus. In ovaries and uterus, Cd(2+) inhibits competitively, while Hg(2+) inhibits noncompetitively in both organs. The observed inhibition was a consequence of direct action of the chosen metal ions on the enzyme protein and by decreasing ATP hydrolysis, Hg(2+) and Cd(2+) may affect mammalian fertility.
Milosević
Maja
M
Institute of Nuclear Sciences Vinca, Laboratory for Molecular Biology and Endocrinology, Belgrade, Serbia and Montenegro.
Petrović
Snjezana
S
Demajo
Miroslav
M
Horvat
Anica
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002104:Cadmium / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000633:toxicity; D005260:Female; D005298:Fertility / Q000187:drug effects / Q000502:physiology; D006868:Hydrolysis; D008628:Mercury / Q000494:pharmacology; D008670:Metals / Q000633:toxicity*; D010053:Ovary / Q000187:drug effects* / Q000201:enzymology; D051381:Rats; D014599:Uterus / Q000187:drug effects* / Q000201:enzymology
D004791:Enzyme Inhibitors; D008670:Metals; D002104:Cadmium; D000255:Adenosine Triphosphate; D017301:Ca(2+) Mg(2+)-ATPase; D008628:Mercury