Dopamine-mediated effects induced by metoclopramide simultaneously on adrenocorticotropic hormone and prolactin in patients with pituitary and/or hypothalamic disorders

We recently demonstrated that metoclopramide acts in the hypothalamus and pituitary to release ACTH through an antidopaminergic (catecholaminergic) mechanism, and that the metoclopramide-induced cortisol response was absent in patients with prolactinoma and acromegaly with hyperprolactinemia, possibly due to an endogenous catecholamine deficiency in these diseases [l]. In the present study, to extend these observations, a 20-mg metoclopramide test was carried out on 25 patients with pituitary and/or hypothalamic disorders other than prolactinoma and acromegaly, and the results were compared with those of the insulin hypoglycemia test.