Plasma and erythrocyte cations and permeability of the erythrocyte membrane to cations in essential hypertension.

Untreated African patients with essential hypertension were found to have high plasma sodium and low plasma potassium. The red cel contents of these cations determined from the same sample of blood were found to be high for sodium and normal for potassium. The passive permeability of the erythrocytes for potassium was lower in hypertensives than in controls. The ouabain-sensitive active sodium efflux was lower in hypertensives than in controls. The relationships between the erythrocyte cation content and the total body content of the cations, and between the membrane function in red cells and other cells of the body are discussed.