title: Serotonin antagonist pirenperone inhibits sexual behavior in the male rat: attenuation by quipazine.
abstract: Peripheral administration of the serotonin (5-HT) antagonist pirenperone produced a dose dependent inhibition of sexual behavior in sexually naive and experienced male rats. In Experiment 1, both 75 micrograms/kg and 150 micrograms/kg pirenperone significantly reduced the proportion of naive males mounting, while 150 micrograms/kg also reduced the proportion of naive males intromitting and ejaculating. In Experiment 2, both 75 micrograms/kg and 150 micrograms/kg pirenperone significantly increased mount and intromission latencies in sexually experienced males, as well as decreased intromission frequency, with 150 micrograms/kg more potent in each regard. The 150 micrograms/kg dose also increased the post-ejaculatory interval, and decreased both mount frequency and copulatory efficiency. In Experiment 3, both 150 micrograms/kg pirenperone and 3 mg/kg of the 5-HT agonist quipazine produced significant inhibition of male sexual behavior; however, when co-administered, inhibitory effects of each drug were significantly attenuated. The mutual attenuation of effects by a 5-HT agonist and a 5-HT antagonist suggests that the observed effects of both of these drugs were serotonergically mediated. In the final experiment, the 5-HT antagonist ketanserin was shown to inhibit sexual behavior in a manner similar to that of pirenperone. Results suggest a facilitatory, as well as an inhibitory role for 5-HT in male sexual behavior.
authors.forename: S D
authors.initials: SD
authors.lastname: Mendelson
authors.forename: B B
authors.initials: BB
authors.lastname: Gorzalka
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D010134:Fenclonine / Q000494:pharmacology; D007650:Ketanserin; D008297:Male; D010880:Piperidines / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology*; D011814:Quipazine / Q000494:pharmacology*; D051381:Rats; D012702:Serotonin Antagonists / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D014149:Tranquilizing Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*
chemical_list: D010880:Piperidines; D011804:Quinolines; D012702:Serotonin Antagonists; D014149:Tranquilizing Agents; D011814:Quipazine; D007650:Ketanserin; D010134:Fenclonine; C034177:pirenperone