Racial differences in bumetanide-sensitive cotransport and N-ethylmaleimide-stimulated potassium efflux.
Racial differences in erythrocyte potassium effluxes mediated by two loop-diuretic sensitive modes of cotransport were compared. In red cells loaded to contain approximately equimolar amounts of sodium and potassium, black subjects had lower bumetanide-sensitive sodium-dependent net potassium effluxes as compared to whites. In fresh, washed erythrocytes pretreated with N-ethylmaleimide (NEM), maximal net potassium efflux was greater in blacks than in whites. NEM-stimulated potassium efflux was partially inhibited by bumetanide but only at very high concentrations. The quantitative differences in these two modes of potassium efflux suggest that NEM-stimulated potassium efflux is not an altered mode of sodium-dependent potassium efflux.
D001692:Biological Transport / Q000187:drug effects; D044383:Black People; D002034:Bumetanide / Q000494:pharmacology*; D004232:Diuretics / Q000494:pharmacology*; D004912:Erythrocytes / Q000378:metabolism*; D005033:Ethylmaleimide / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D009761:Nystatin / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000097:blood*; D044469:Racial Groups; D012964:Sodium / Q000097:blood; D044465:White People
D004232:Diuretics; D002034:Bumetanide; D009761:Nystatin; D010042:Ouabain; D012964:Sodium; D005033:Ethylmaleimide; D011188:Potassium