Evaluation of intra-erythrocyte Na+ activity in persons at high risk for essential arterial hypertension and as an aid in differential diagnosis from secondary forms of hypertension

The intracellular "Na+ activity" was measured in erythrocytes of normotensive subjects (46), in essential hypertensive patients (18), in their children (20) and in patients with secondary hypertension (8). In normotensive subjects without a genetic trait of hypertension intracellular "Na+ activity" was 7.3 +/- 0.8 mmol/l, in secondary hypertensive patients was 7.5 +/- 0.6 mmol/l, in essential hypertensive patients was 10.9 +/- 1.1 mmol/l and in their children was 8.6 +/- 2.1 mmol/l. In this group (children) it was possible to differentiate between 2 population, the 1 degree with height intracellular "Na+ activity" (8); the 2 degrees with normal intracellular "Na+ activity".