Aldosterone and other mineralocorticoids in Bartter's syndrome.

Plasma levels of aldosterone and other mineralocorticoids were determined in six patients with Bartter's syndrome. In spite of a remarkable elevation of plasma renin activity, the plasma aldosterone and 18-hydroxycorticosterone levels varied in each patient. These levels were slightly increased in three of the six patients, almost normal in two patients, and slightly reduced in one patient. The plasma deoxycorticosterone and corticosterone levels were within the normal range in all patients. The responses of plasma aldosterone to infusion of angiotensin II were reduced in all patients. Plasma aldosterone and 18-hydroxycorticosterone significantly increased with supplement of potassium, and the responses of plasma aldosterone to infusion of angiotensin II were also improved after supplement of potassium. Our results suggest that plasma aldosterone in Bartter's syndrome is dependent on potassium balance, even though plasma renin activity is remarkably increased, and that hyperaldosteronism is not an inevitable finding in Bartter's syndrome.