Pituitary - adrenocortical function in patients during treatment with the angiotensin-converting enzyme inhibitor captopril.

To study effects on pituitary-adrenocortical activity of a sustained block of angiotensin II formation, six 'drug-resistant' patients with essential hypertension were studied before and during treatment with an inhibitor of the angiotensin-converting enzyme (Captopril, SQ 14,225). The drug was given in increasing doses (100-400 mg/day) for 2 weeks whilst patients received a moderately restricted sodium intake (60-80 mmol/day). Immunoreactive ACTH, cortisol, aldosterone, plasma renin activity (PRA) and the activity of the angiotensin-converting enzyme (ACE) were measured in blood samples drawn at 0800-0900 h. Urinary excretion of cortisol and aldosterone were measured in 24-h urine collections. Further information on pituitary-adreno-cortical function was obtained by measuring serial plasma corticosteroid levels after submaximal stimulation with a synthetic ACTH preparation. ACTH and cortisol did not change an observation which does not support the hypothesis that glucocorticoid activity is influenced by a decrease in plasma angiotensin II concentrations.