Effects of dexamethasone on neuroendocrine and psychological responses to L-tryptophan infusion

Citation
Rj. Porter et al., Effects of dexamethasone on neuroendocrine and psychological responses to L-tryptophan infusion, PSYCHOPHAR, 143(1), 1999, pp. 64-71
Citations number
56
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
Volume
143
Issue
1
Year of publication
1999
Pages
64 - 71
Database
ISI
SICI code
Abstract
5-Hydroxytryptamine(1A) (5-HT1A) receptors have been shown to be suppressed by corticosteroid hormones in a variety of animal experimental paradigms. This effect may be central to the pathophysiology of severe clinical depres sive illness, a condition in which 5-HT1A receptor function is reduced and corticosteroid hormones are elevated. Evidence suggests that the growth hor mone (GH) response to L-tryptophan (L-TRP) is mediated by 5-HT1A receptors. This response has been shown to be reduced following acute administration of hydrocortisone. The purpose of this study was to examine the effects of acute administration of dexamethasone. in normal volunteers, on hormonal an d psychological responses to L-TRP infusion. Methods: Sixteen healthy male volunteers took part in a random order, double blind study, in which 5 mg d examethasone or placebo was administered 11 h before infusion of L-TRP. Res ults: Pretreatment with dexamethasone had no effect on the GH response to t he infusion. However, baseline prolactin (PRL) was significantly reduced, a s was the prolactin response to the infusion. Conclusions: These data contr ast with a previous study using hydrocortisone in the same paradigm and dem onstrate important functional differences between dexamethasone and hydroco rtisone.