Prolactin secretion by metoclopramide in man.
Six men and nine women were given intravenous injections of 2.5 mg of metoclopramide to assess its potential as a stimulus to prolactin release. Following the administration of metoclopramide, there was prompt increase in serum prolactin to a peak response of 38.2 +/- 3.9 ng/ml in men and 103 +/- 10.2 ng/ml in women. The prolactin response to metoclopramide in men was compared with the response to 400 mug of TRH in 10 men. The peak response after TRH was 22.4 +/- 2.2 ng/ml, which was significantly less than that observed after metoclopramide. Pretreatment with 500 mg of L-dopa suppressed the prolactin response to metoclopramide in 6 men to a mean response of 16.3 +/- 4.3 ng/ml. We have concluded that metoclopramide is a safe, reliable, and potent stimulus of prolactin secretion and exerts this effect by blocking dopamine receptors in the hypothalamus and decreasing prolactin inhibiting factor. It is free of side effects and is a useful alternative to chlorpromazine.
D000293:Adolescent; D000328:Adult; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D008787:Metoclopramide / Q000037:antagonists & inhibitors; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*; D011389:Prolactin Release-Inhibiting Factors / Q000378:metabolism; D013268:Stimulation, Chemical; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
D007980:Levodopa; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D011389:Prolactin Release-Inhibiting Factors; D008787:Metoclopramide