Influence of monovalent ions on the activity of the (Ca2+ + Mg2+)-ATPase and Ca2+ -transport of human red blood cells.
In reconstituted human red blood cells a difference was found in (Ca2+ + Mg2+)-ATPase activity and in Ca2+ efflux at 37 degrees C, depending on the side of the membrane at which the monovalent cations K+ and Na+ were placed. Under the conditions used, (Ca2+ + Mg2+)-ATPase activity and Ca2+ efflux was highest when K+ (35 +/- 0.5 mM (+/- S.E.), mean of four experiments) was at the inside and Na+ (130 mM) at the outside of the ghost membrane.
D001693:Biological Transport, Active / Q000187:drug effects; D017301:Ca(2+) Mg(2+)-ATPase; D002118:Calcium / Q000097:blood*; D000252:Calcium-Transporting ATPases / Q000097:blood*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008274:Magnesium / Q000097:blood; D011188:Potassium / Q000494:pharmacology*; D012964:Sodium / Q000494:pharmacology*
D012964:Sodium; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D008274:Magnesium; D011188:Potassium; D002118:Calcium