title: DOI-induced inhibition of copulatory behavior in male rats: reversal by 5-HT2 antagonists.
abstract: Relatively little is known regarding the role of 5-HT2 receptor activity in male rat sexual behavior. Previous work has yielded equivocal results, and both facilitation and inhibition of copulation have been reported to follow administration of selective 5-HT2 antagonists. In the present series of experiments, the ability of a variety of 5-HT2 antagonists to block inhibition induced by the 5-HT2/5-HT1C agonist DOI was examined. Systemic ritanserin, pirenperone and ketanserin all potently blocked DOI-induced (1.0 mg/kg SC) inhibition of mounts, intromissions and ejaculations. None of these drugs influenced the sexual behavior of the male rats when given alone in doses that effectively blocked DOI-induced inhibition. In addition, unlike ritanserin and ketanserin, pirenperone produced a biphasic effect on DOI-induced inhibition, exhibiting a diminished blockade at higher doses. This may be due to activity at receptors other than 5-HT2. Overall, the present data suggest that activity at 5-HT2 receptors mediates an inhibition of male rat sexual behavior.
authors.affiliation: University of British Columbia, Vancouver, Canada.
authors.forename: N V
authors.initials: NV
authors.lastname: Watson
authors.forename: B B
authors.initials: BB
authors.lastname: Gorzalka
mesh_terms: D000662:Amphetamines / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D003307:Copulation / Q000187:drug effects*; D004542:Ejaculation / Q000187:drug effects; D005260:Female; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D016713:Ritanserin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology*; D014149:Tranquilizing Agents / Q000494:pharmacology
chemical_list: D000662:Amphetamines; D010880:Piperidines; D012702:Serotonin Antagonists; D014149:Tranquilizing Agents; D016713:Ritanserin; D007650:Ketanserin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine; C034177:pirenperone