Characterization of Na(+)-independent Mg2+ efflux from erythrocytes.
Na(+)-independent Mg2+ efflux from Mg2(+)-loaded human, rat and chicken erythrocytes was reduced by extracellular Cl-. Na(+)-independent Mg2+ efflux at low extracellular Cl- concentration (sucrose medium) was inhibited by SITS and was nearly insensitive to SITS in 150 mM choline Cl medium. The inhibition of Mg2+ efflux by extracellular Cl- and DIDS could be overcome by the lipophilic permeant tetraphenylphosphonium cation. Na(+)-independent Mg2+ efflux from human and rat erythrocytes in sucrose and choline Cl medium was inhibited by cAMP and by amiloride and amiloride analogues. The results indicate that Na(+)-independent Mg2+ efflux in high Cl- medium is performed by a similar or the same Mg2+ efflux system, operating in sucrose medium in which the efflux of Mg2+ is accompanied by the efflux of Cl- for charge compensation.
Günther
T
T
Institute of Molecular Biology and Biochemistry, Free University of Berlin, FRG.
Vormann
J
J
D000818:Animals; D002645:Chickens; D002713:Chlorine / Q000378:metabolism; D000242:Cyclic AMP / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008274:Magnesium / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D013395:Sucrose
D002713:Chlorine; D013395:Sucrose; D012964:Sodium; D000242:Cyclic AMP; D008274:Magnesium