The involvement of methysergide-sensitive receptors and prostaglandins in the hyperthermia evoked by 5-HT in the cat.
In the unanesthetized cat, an injection of 0.01 or 0.03 M 5-hydroxytryptamine into the rostral hypothalamus produced an immediate, short-lasting increase or decrease in body temperature. A delayed and long-lasting hyperthermia often followed the initial response. When indomethacin, 10 mg/kg, was administered intraperitoneally 3 hours prior to an injection of 5-hydroxytryptamine at sites which produced an initial increase in body temperature, the secondary hyperthermia was reduced or abolished but the immediate response remained undiminished. Pretreatment with methysergide, 2 mg/kg i.p., attenuated or abolished the initial temperature increase but did not reduce the delayed hyperthermia. The results suggest that the initial rise in body temperature produced by 5-hydroxytryptamine is mediated by activation of methysergide-sensitive 5-HT receptors and that the response is independent of prostaglandin release. The secondary hyperthermia, on the other hand, is apparently mediated by a sustained release of prostaglandins.
D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D002415:Cats; D003864:Depression, Chemical; D005260:Female; D007031:Hypothalamus / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008784:Methysergide / Q000494:pharmacology*; D011453:Prostaglandins / Q000494:pharmacology*; D011955:Receptors, Drug; D012701:Serotonin / Q000494:pharmacology*; D013997:Time Factors
D011453:Prostaglandins; D011955:Receptors, Drug; D012701:Serotonin; D007213:Indomethacin; D008784:Methysergide