Erythrocyte contents of electrolytes (Na, K, Mg, Zn) in healthy male controls and offspring to established hypertensive patients: a follow-up study.

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 less than 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.