Sodium transport in hypertension: assessment of membrane-associated defects in South African black and white hypertensives.

Sodium transport was studied in red cells taken from four groups of patients, whites or blacks, and normotensive or hypertensive, with approximately ten patients in each group. There were no differences between normotensive and hypertensive whites. Normotensive blacks had higher rates of sodium-proton exchange than did the other groups, and hypertensive blacks had higher rates of efflux via the sodium-potassium ATPase than did other groups. These data support proposals that hypertension in black subjects is linked to abnormalities of control of intracellular sodium.