EPISODIC SECRETION OF ALDOSTERONE IN PRIMARY ALDOSTERONISM: RELATIONSHIP TO CORTISOL

SUMMARY Plasma aldosterone, plasma cortisol and plasma renin activity were determined at short time intervals in three supine patients suffering from primary aldosteronism. The patients were studied both under normal conditions and during suppression of ACTH secretion by dexamethasone. Though abnormally high levels were found, aldosterone was secreted episodically in each patient while plasma renin activity was uniformly undetectable. In each patient the secretory episodes of aldosterone were paralleled by those of cortisol indicating that physiological variations in ACTH secretion markedly altered the secretion of aldosterone. The assumption that ACTH played an important role in the regulation of aldosterone secretion in primary aldosteronism was strengthened by the observation that, contrary to normal controls, dexamethasone produced a significant decrease in plasma aldosterone concentrations and that during suppression of ACTH secretion no secretory episodes of aldosterone were observed.