Domperidone: a novel agent for the investigation of anterior pituitary function and control in man.

Administration of the novel agent domperidone (10 mg iv), which combines the properties of specific dopamine receptor blockade and inability to cross the blood-brain barrier, leads to acute and significant TSH and PRL release in man. This suggests that the in vivo site of action of endogenous dopamine in the inhibitory control of these two hormones is either the anterior pituitary or median eminence, since these tissues lie outside the blood-brain barrier. This class of drug is of potential value both clinically and experimentally in the investigation of anterior pituitary control mechanisms.