Intracellular concentration and transmembrane fluxes of sodium and potassium in erythrocytes of white normal male subjects with and without a family history of hypertension.

Compared with white normal males without a family history of hypertension (n = 43), red blood cells of white normal males with such a family history (n = 17) had a higher (P less than 0.01) intracellular sodium concentration (8.07 +/- 0.30 versus 7.33 +/- 0.17 mmol/l cells). This could be at least partly due to their lower (P less than 0.001) frusemide-sensitive sodium efflux rate (250 +/- 19 versus 424 +/- 23 mumol/l cells/h). Also their ouabain-resistant 86Rb-uptake (0.81 +/- 0.06 versus 0.97 +/- 0.03 mumol/l cells/h) was lower (P less than 0.05). Potassium concentration in the red blood cells was similar in both groups.