Abnormal cation composition and transport in erythrocytes from hypertensive patients

Red cell sodium and potassium were determined in 100 untreated subjects with uncomplicated essential hypertension and compared with the values from 908 healthy normotensive control subjects. Red cell sodium concentration (expressed as mmol/l of erythrocytes) was significantly higher in hypertensive than in normotensive subjects. Red cell potassium concentration (in mmol/l of erythrocytes) was not significantly different in the two groups. Passive efflux of red cell potassium into buffered isotonic sucrose solution determined in eight hypertensive and nine normotensive subjects showed a lower potassium efflux rate in the hypertensive subjects. Comparison of active sodium efflux in sixteen hypertensive and fourteen normotensive subjects showed that ouabain-sensitive active sodium efflux was higher in red cells of normotensive than in those of hypertensive subjects.