Characterization of Mg2+ efflux from human, rat and chicken erythrocytes.
Net Mg2+ efflux from Mg2+-loaded, human, rat and chicken erythrocytes was measured in sucrose, NaCl and choline Cl medium. Thus, Na+-dependent (NaCl minus choline Cl) and Na+-independent Mg2+ efflux (in sucrose) were determined. Na+-dependent Mg2+ efflux amounted to 0.16, 8.9 and 1.57 mmol/l cells x 30 min, Na+-independent Mg2+ efflux amounted to 0.89, 1.55 and 0.37 mmol/l cells x 30 min for human, rat and chicken erythrocytes. Na+-dependent Mg2+ efflux was inhibited by quinidine. Na+-independent Mg2+ efflux was inhibited by SITS and Cl-. A small fraction of Na+-independent Mg2+ efflux (in choline Cl) was resistant to SITS and Cl-. Ca2+ loading increased Mg2+ efflux similar to K+ efflux (Gardos effect). This effect was differently expressed in human and chicken erythrocytes.
Günther
T
T
Institute of Molecular Biology and Biochemistry, Free University of Berlin, FRG.
Vormann
J
J
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D002645:Chickens; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D008274:Magnesium / Q000097:blood*; D051381:Rats; D013045:Species Specificity
D008274:Magnesium; D002118:Calcium