Yohimbine and aldosterone responsiveness to angiotensin II or corticotrophin in normal subjects.

In normal man the sympathetic nervous system exerts an inhibitory influence on aldosterone responsiveness to angiotensin II. The possible role of alpha-2 adrenoceptors was assessed by studying the changes of plasma aldosterone during an angiotensin II infusion at the dose of 1, 2, 5 and 10 ng/kg. min or after corticotrophin infusion, 0.25 mg, in 8 normal subjects before and after treatment with the selective alpha-2 adrenoceptor antagonist, yohimbine, at a maximal dosage of 60 mg daily. Yohimbine did not modify blood pressure, body weight, the supine levels of angiotensin II, renin and aldosterone, the pressor response to angiotensin II and the correlation relating plasma aldosterone to plasma angiotensin II obtained during infusion studies. These findings suggest that the inhibitory influence of the sympathetic nervous system on aldosterone responsiveness to angiotensin II.