Control of plasma aldosterone in a patient with Conn's syndrome before and during spironolactone medication

In a patient suffering from Conn's syndrome analysis of short-time fluctuations of plasma aldosterone, plasma cortisol and plasma renin activity were performed before and after a 9-months therapy period with spironolactone. Under the former conditions aldosterone was secreted episodically and a highly significant correlation was found between plasma aldosterone and plasma cortisol (r=0.817, p is less than 0.001) while plasma renin activity was undetectable (is less than 0.16 ng/ml/3hr). Following a 9-month therapy with spironolactone episodic secretion of aldosterone and the significant correlation between aldosterone and cortisol persisted (r=0.819, p less than 0.001) in the presence of an abnormally high plasma renin activity. First when the secretion of ACTH was suppressed by dexamethasone a weak correlation was found between renin activity and aldosterone (r=0.517, p is less than 0.05). Our results show that both before and after a 9-months therapy with spironolactone episodic aldosterone release of an aldosterone producing adrenal adenoma was mediated through ACTH and that endogeneous angiotensin II had no or only little influence.