Amitriptyline and femoxetine, but not clomipramine or citalopram, antagonize hyperthermia induced by directly acting 5-hydroxytryptamine-like drugs in heat adapted rats.
5-HT uptake inhibitors and pirenperone (a 5-HT2 receptor antagonist), which in previous experiments antagonized fenfluramine (5-HT releaser)-induced hyperthermia in heat adapted rats, were tested against hyperthermia induced by the directly acting 5-HT agonist--m-CPP and quipazine. Pirenperone and --to a lesser degree--amitriptyline and femoxetine antagonized the hyperthermia. Citalopram and clomipramine were inactive. It is concluded that hyperthermia induced by 5-HT-like drugs in rats is due to the stimulation of the 5-HT2 receptor and that the antagonistic effect of citalopram and clomipramine against fenfluramine-induced hyperthermia might be connected with their effect on the uptake of 5-HT.
D000222:Adaptation, Physiological; D000639:Amitriptyline / Q000494:pharmacology; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D015283:Citalopram; D002997:Clomipramine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011437:Propylamines / Q000494:pharmacology; D011814:Quipazine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*
D010879:Piperazines; D010880:Piperidines; D011437:Propylamines; D012702:Serotonin Antagonists; D015283:Citalopram; D000639:Amitriptyline; D012701:Serotonin; D011814:Quipazine; C010655:femoxetine; D002997:Clomipramine; C015068:1-(3-chlorophenyl)piperazine; C034177:pirenperone