Plasma aldosterone response to metoclopramide in patients with Cushing's disease

The acute effect of metoclopramide on aldosterone and prolactin levels were studied in 8 control subjects and 11 patients with Cushing's disease. Metoclopramide (10 mg i.v.) induced a similar plasma prolactin response in control subjects and patients. No difference was found in basal aldosterone levels between the two groups. Apart from a more delayed aldosterone response to metoclopramide in the Cushing's disease group, no significant difference in the peak aldosterone values was found between the patients and controls. The short-term treatment with DA2-receptor agonist bromocriptine was without effect on aldosterone response to metoclopramide in the Cushing's disease group. These results argue against an altered dopaminergic control of aldosterone secretion in patients with Cushing's disease. The lack of a bromocriptine effect on aldosterone response to metoclopramide is in accordance with the concept that the dopamine receptors involved in aldosterone regulation differ from classical DA2 receptors.