Skeletal muscle water and electrolytes in treated and untreated essential hypertension.

The question whether body electrolyte composition in patients with primary hypertension differs from that of normotensive subjects is still controversial. The aim of the present work was to investigate on water, electrolyte, and nitrogen muscle cell composition in essential human hypertension. Also the effects of antihypertensive drugs on muscle electrolyte contents were analyzed. The results indicate that muscle Na was higher and muscle K was lower in essential hypertensives in comparison with controls. Muscle water, Mg, and nitrogen were not different in treated patients (with or without diuretics) in comparison with untreated hypertensive patients. But in hypertensive patients treated with diuretics, Nam was higher and Km was lower than in untreated patients. Several mechanisms may explain the changes on muscle electrolyte composition in primary hypertension, but the cellular mechanism involving abnormalities in ion pump and electrolyte transmembrane fluxes are the most probable. The therapy with antihypertensive drugs especially diuretics, seems to enhance different muscle electrolyte patterns in essential hypertension.