Abstract
Erythrocyte sodium, potassium, zinc and magnesium were measured in 56 male offspring to essential hypertensive patients and compared with 46 matched controls. The same parameters were measured again 4–6 months apart in 31 offspring and eight controls. Intracellular sodium was significantly higher in offspring (P<0.001). There was a highly significant correlation between the two intra-individual measurements of intracellular sodium, potassium and zinc but not for magnesium. Sodium in erythrocytes is probably an indicator of the activity of the sodium-pump and could possibly be used as a genetic marker in the future investigations of individuals with heredity for severe, essential hypertension.