title: The effect of metergoline on endocrine responses to L-tryptophan.
abstract: The effects of the 5-HT receptor antagonist, metergoline, on the prolactin and growth hormone responses to intravenous L-tryptophan were assessed in seven normal subjects. Pretreatment with metergoline lowered baseline prolactin concentration and abol ished the increase in prolactin following L-tryptophan. In contrast, neither baseline nor the response to L-tryptophan was altered by metergoline. These results are consistent with the proposal that the prolactin response to L-tryptophan is mediated by 5-HT(1) receptors; however, metergoline might also reduce prolactin responses by a dopaminergic action. The nature of the 5-HT receptor involved in the growth hormone response to L-tryptophan remains to be identified.
authors.affiliation: MRC Unit of Clinical Pharmacology and University Department of Psychiatry, Research Unit, Littlemore Hospital, Littlemore, Oxford OX4 4XN.
authors.forename: S L
authors.initials: SL
authors.lastname: McCance
authors.forename: P J
authors.initials: PJ
authors.lastname: Cowen
authors.forename: H
authors.initials: H
authors.lastname: Waller
authors.forename: D G
authors.initials: DG
authors.lastname: Grahame-Smith