Cardiovascular, renal and endocrine effects of alpha-human atrial natriuretic peptide in patients with Cushing's syndrome and primary aldosteronism.

The pharmacological effects of synthetic alpha-human atrial natriuretic peptide (alpha-hANP) in patients with Cushing's syndrome and primary aldosteronism were compared with those in normal volunteers. An infusion of synthetic alpha-hANP at 0.1 microgram/kg per min for 20 min produced a maximal plasma hANP level of 800-1200 pg/ml in patients with Cushing's syndrome and primary aldosteronism, and in normal subjects. There were significant decreases in the mean blood pressure (-10 to -15 mmHg) in patients with Cushing's syndrome and primary aldosteronism, similar to those in normal subjects. The plasma cyclic 3'5'-guanosine monophosphate (cGMP) concentrations of both groups of patients were increased fivefold over the baseline level following the infusion. Infusion of synthetic alpha-hANP caused a greater increase in the rate of sodium excretion in patients with Cushing's syndrome and primary aldosteronism compared with normal volunteers. The plasma cortisol and aldosterone concentrations did not, however, significantly change during alpha-hANP infusion in either the patients with Cushing's syndrome or those with primary aldosteronism. As synthetic alpha-hANP has a potent hypotensive effect in hypertensive patients with Cushing's syndrome and primary aldosteronism, a significant reduction in blood pressure and natriuresis seems to occur without affecting adrenocortical steroidogenesis.