title: Does metergoline selectively attenuate 5-HT mediated prolactin release?
abstract: Administration of the non-selective 5-HT receptor antagonist metergoline (0.5 mg/kg) to male rats attenuated the prolactin response to the 5-HT releasing agent d-fenfluramine (7.5 mg/kg) but not to the dopamine receptor antagonist haloperidol (1.5 mg/kg). In contrast, in healthy male volunteers, pretreatment with metergoline (4 mg orally) abolished the prolactin response to intravenous haloperidol (5 micrograms/kg). The findings suggest that in humans blockade of a prolactin response by a conventional oral dose of metergoline cannot be taken as evidence of involvement of 5-HT-mediated mechanisms.
authors.affiliation: MRC Unit of Clinical Pharmacology, Littlemore Hospital, Oxford, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: Ellis
authors.forename: S E
authors.initials: SE
authors.lastname: Gartside
authors.forename: C J
authors.initials: CJ
authors.lastname: Ware
authors.forename: G M
authors.initials: GM
authors.lastname: Campling
authors.forename: P J
authors.initials: PJ
authors.lastname: Cowen
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D005277:Fenfluramine / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D006801:Humans; D008297:Male; D008711:Metergoline / Q000494:pharmacology*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology*
chemical_list: D012702:Serotonin Antagonists; D008711:Metergoline; D005277:Fenfluramine; D012701:Serotonin; D011388:Prolactin; D006220:Haloperidol