Further evidence showing that the inhibitory action of serotonin on rat masculine sexual behavior is mediated after the stimulation of 5-HT1B receptors.
To explore whether the inhibitory actions of endogenous serotonin on rat male sexual behavior were mediated via the stimulation of the 5-hydroxytryptamine1A (5-HT1A) or 5-HT1B receptor subtypes, two series of studies were undertaken. In the first series, an attempt to block the inhibitory actions of threshold doses of the serotonin precursor 5-hydroxytryptophan (5-HTP, 50 mg/kg) by administering the beta-5-HT antagonist alprenolol (5.0 mg/kg) and the selective beta-blocker practolol (0.5 mg/kg) was made. Both antagonists effectively prevented, at least partially, the inhibitory actions of 5-HTP. In the second series, a possible synergistic effect of a subthreshold dose of 5-HTP (12.5 mg/kg) with low doses of the selective 5-HT1B agonist 1-(m-trifluoro-methylphenyl)piperazine (TFMPP,0.125 mg/kg) or the selective 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT, 0.0625 mg/kg) was investigated. A clear synergistic inhibitory effect of 5-HTP with TFMPP was observed. All data are interpreted based upon the hypothesis suggesting a physiological inhibitory role of the 5-HT1B receptor subtype on male rat sexual behavior.
Fernández-Guasti
A
A
Departamento de Farmacología y Toxicología, CINVESTAV, México D.F.
Rodríguez-Manzo
G
G
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000526:Alprenolol / Q000494:pharmacology; D000818:Animals; D004542:Ejaculation / Q000187:drug effects; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011217:Practolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D010879:Piperazines; D011985:Receptors, Serotonin; C018406:1-(3-trifluoromethylphenyl)piperazine; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000526:Alprenolol; D006916:5-Hydroxytryptophan; D011217:Practolol