[Influence of endogenous renin-angiotensin system on plasma aldosterone responsiveness to metoclopramide].

Hyperresponsiveness of plasma aldosterone to metoclopramide (MCP) was found in the patients with secondary aldosteronism. To understand the mechanisms of aldosterone reactivity to MCP, we examined the changes of its responsiveness to MCP and ACTH in various states of endogenous renin-angiotensin system which were induced by administrating two antihypertensive agents to patients with essential hypertension. Aldosterone responsiveness to both stimulants were accentuated during diuretic antihypertensive therapy in comparison with those before therapy. After adding converting enzyme blocker to diuretic agent, aldosterone reactivity to MCP decreased. These results indicates that aldosterone responsiveness to MCP which was thought to be controlled by changes of endogenous dopamine may be also influenced by the state of endogenous renin-angiotensin system.