Divalent cation transport in kidney slices II. Magnesium transport in kidney cortex slices and effects of diuretics.
We examined the properties of Mg2+ transport in rat kidney cortex slices and the effects of diuretics were also studied. Incubation with 1 mM 2,4-dinitrophenol, or under anaerobic conditions, sharply inhibited Mg2+ influx, while markedly stimulating Mg2+ efflux. Under conditions of hypothermia, partial inhibition of Mg2+ influx and significant enhancement of Mg2+ efflux were observed. Mg2+ influx was not affected by ouabain, by altering CaCl2 concentration in the medium, or by a change of Ca2+ content in the slices. Incubation with 1 mM ethacrynic acid or mersalyl depressed Mg2+ influx and stimulated Mg2+ efflux, p-chloromercuribenzoic acid (5 X 10(-4) M) had a similar effect and furosemide had no effect on Mg2+ transport. These results suggest that Mg2+ influx is mediated by an energy-dependent process which is dissociated from ouabain-sensitive Na+ transport and Ca2+ flux. Sulfhydryl groups may be involved in the process of Mg2+ influx.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism / Q000502:physiology; D002413:Cations, Divalent / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology*; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D051381:Rats; D012964:Sodium / Q000378:metabolism
D002413:Cations, Divalent; D002729:Chloromercuribenzoates; D004232:Diuretics; D012964:Sodium; D008274:Magnesium; D002118:Calcium