Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Intravenous infusion of L-tryptophan (LTP) in 18 normal subjects produced a significant increase in plasma prolactin (PRL), growth hormone (GH), and self-ratings of drowsiness. There was no correlation between the PRL and GH responses, or between the hormonal responses and drowsiness. Saline infusion did not result in endocrine or psychological changes. The effect of LTP on both PRL and GH was dose-related in that LTP 7.5 g produced greater endocrine responses than 5.0 g. It was not significantly decreased by cyproheptadine, a 5-HT receptor antagonist. Schizophrenic patients receiving neuroleptics had increased PRL response to LTP, possibly because of the drug-induced disinhibition of PRL release. Their GH response to LTP was markedly decreased. The mechanism of this effect requires further investigation.

Type

Journal article

Journal

Psychopharmacology (Berl)

Publication Date

1985

Volume

86

Pages

164 - 169

Keywords

Adult, Cyproheptadine, Female, Growth Hormone, Humans, Hypothalamo-Hypophyseal System, Male, Prolactin, Reference Values, Schizophrenia, Serotonin, Sleep Stages, Synaptic Transmission, Tryptophan