Familial abnormality of erythrocyte cation transport in essential hypertension

Cation transport across the red-cell membrane was studied in subjects with essential hypertension and their relatives using rubidium-86 as an analogue of potassium. The activity of the ouabain-sensitive sodium-potassium pump was significantly greater in patients with untreated essential hypertension than in controls (p less than 0.001). No clear separation was seen between normotensive and hypertensive subjects. Activity of the sodium-potassium pump was also increased in a proportion of normotensive relatives of subjects with essential hypertension. Rubidium uptake was significantly lower in normotensive black subjects than in normotensive whites, the difference being in a ouabain-resistant pathway of cation transport. These results provide further evidence that a defect in membrane cation transport contributes to the pathogenesis of essential hypertension.