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Updated: May 26, 2026
![Radiosynthesis of 1-(2-[18F]Fluoroethyl)-L-Tryptophan using a One-pot, Two-step Protocol](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F63025.jpg&w=3840&q=50)
Radiosynthesis of 1-(2-[18F]Fluoroethyl)-L-Tryptophan using a One-pot, Two-step Protocol
Published on: September 21, 2021
The effect of metergoline on endocrine responses to L-tryptophan
S L McCance1, P J Cowen, H Waller
1MRC Unit of Clinical Pharmacology and University Department of Psychiatry, Research Unit, Littlemore Hospital, Littlemore, Oxford OX4 4XN.
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.
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