Metoclopramide stimulates prolactin secretion in man.
Serum prolactin concentrations increased approximately 6-fold after oral or intravenous administration of 10 mg of metoclopramide to adult men. Prolactin remained significantly elevated up to 9 h after oral metoclopramide and for at least 2 h after iv metoclopramide. Bethanechol did not increase serum prolactin, and atropine did not inhibit metoclopramide-induced prolactin elevation, suggesting that the cholinergic-like properties of metoclopramide were not responsible for the observed prolactin responses. Pre-treatment with 500 mg L-dopa inhibited the early metoclopramide-induced prolactin increase, which is consistent with the possibility that metoclopramide acts by inhibiting dopamine-mediated hypothalamic secretion of prolactin inhibitory factor. As a potent stimulus of prolactin release, metoclopramide may be useful in clinical investigation of hypothalamic-pituitary function.
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D004295:Dihydroxyphenylalanine / Q000494:pharmacology; D006801:Humans; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008688:Methacholine Compounds / Q000494:pharmacology; D008787:Metoclopramide / Q000008:administration & dosage / Q000494:pharmacology*; D008875:Middle Aged; D011388:Prolactin / Q000097:blood*; D013997:Time Factors
D008688:Methacholine Compounds; D004295:Dihydroxyphenylalanine; D011388:Prolactin; D008787:Metoclopramide