Acute effects of venlafaxine and paroxetine on serotonergic transmission in human volunteers

Citation
Rj. Porter et al., Acute effects of venlafaxine and paroxetine on serotonergic transmission in human volunteers, PSYCHOPHAR, 146(2), 1999, pp. 194-198
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
Volume
146
Issue
2
Year of publication
1999
Pages
194 - 198
Database
ISI
SICI code
Abstract
Rationale: Antidepressant drugs are thought to enhance serotonergic neurotr ansmission through postsynaptic 5-HT1A receptors. This effect is delayed in animals and may be paralleled by a delay in the onset of a clinical respon se in humans. In humans, the growth hormone (GH) response to intravenous L- tryptophan (IV L-TRP) is blocked by the 5-HT1A antagonist pindolol and the prolactin response is blunted. Both are therefore thought to be a useful me asure of 5-HT1A receptor function. Clomipramine has previously been found t o enhance the GH and prolactin responses to IV L-TRP after only 2 h. Object ive: The purpose of this study was to use this method to investigate the ef fects of newer antidepressants on 5-HT1A receptor-mediated function, Method s: Twelve healthy male volunteers took part in a random order, double blind study, in which 18.75 mg venlafaxine, 5 mg paroxetine or placebo was admin istered 3 h before infusion of L-TRP. Results: Pretreatment with venlafaxin e significantly enhanced the growth hormone (GH) response to the infusion c ompared with pretreatment with placebo. There was no significant difference between the GH response following paroxetine compared with placebo or with venlafaxine. Conclusions: The data suggest enhancement of transmission thr ough postsynaptic 5-HT1A receptors by venlafaxine but not paroxetine, after only 3 h.