On the role of dopamine receptors in aldosterone secretion.

We studied the effects of infusion of dopamine (4 microgram/kg/min for 120 min) alone or with domperidone infusion (235 microgram/min for 120 min) on aldosterone secretion before and after stimulation by ACTH (0,5 mg i.v.) in normal subjects. We also studied the effects, of pimozide (12 mg p.o.), of domperidone infusion (235 microgram/min for 120 min) before and after stimulation with ACTH (0,5 mg i.v.) on aldosterone secretion in two other sets of normal subjects. The infusion of dopamine does not modify the basal secretion of aldosterone whereas in other trials it caused reduction (P less than 0,05) of blood aldosterone response to ACTH versus controls. Domperidone and pimozide, D2 antagonist, do not modify the aldosterone secretion before and after ACTH stimulation. Furthermore domperidone does not remove inhibition of dopamine on aldosterone response to ACTH. We can exclude an action of central or peripheral D2 dopaminergic receptors in aldosterone secretion in man. Dopamine, which does not cross the blood brain barrier, reduced the blood aldosterone response to ACTH; for those reasons we can hypothesize that receptors D1, stimulated by dopamine modulate aldosterone secretion.