[Is there a relation between the renin-angiotensin-aldosterone system and vasopressin secretion in essential...

103 patients with mild or moderately severe essential hypertension and 35 healthy normotensive subjects were examined. In all patients examined plasma osmolality, plasma renin activity and plasma level of vasopressin and aldosterone were estimated twice: first after administration of a diet with a sodium chloride content of 100 to 120 mmol/a day and 8 hours recumbency and a second time after 3 days of dietary sodium chloride restriction (20 mmol/a day) and 3-4 hours upright position. In hypertensives independent of the behaviour of the plasma renin activity similar values of the plasma osmolality, the plasma level of vasopressin and the aldosterone level could be established as in healthy persons. In contrast to normals in hypertensive subjects no significant correlation between plasma osmolality or plasma renin activity and plasma level of vasopressin and aldosterone was stated. In spite of normal levels of vasopressin and aldosterone a significant correlation between the plasma level of vasopressin and aldosterone and the systolic blood pressure was found in hypertensive patients. From the results obtained in this study follows that in hypertensive patients the plasma osmolality is only of secondary importance for the secretion of vasopressin and aldosterone and for the plasma renin activity. The importance of plasma vasopressin and aldosterone in the pathogenesis of hypertension seems to be probable but not yet unanimously proved.