Hypothermia induced by the putative 5-HT1A agonists LY165163 and 8-OH-DPAT is not prevented by 5-HT depletion.
The putative 5-HT1A agonist 1-[2-(4-aminophenyl)ethyl]-4-(3-trifluoromethylphenyl)piperazine (LY165163, PAPP) (1, 2, 4, 10 mg/kg s.c.) caused a significant and dose-dependent hypothermia in rats, 30 and 60 min after injection. The decreases of temperature were less marked than that caused by 8-OH-DPAT 1 mg/kg s.c.). Depletion of brain serotonin (5-HT) by 91% following pretreatment with p-chlorophenylalanine (pCPA) (150 mg/kg i.p. on three successive days) significantly enhanced the hypothermic effects of both 8-OH-DPAT (0.25 mg/kg s.c.) and LY165163 (4 mg/kg s.c.). LY165163-induced hypothermia was also somewhat enhanced following depletion of hypothalamic 5-HT by 76% after infusion of 5,7-dihydroxytryptamine (5,7-DHT) (150 micrograms) into the third ventricle. Results indicate that the hypothermia induced by the putative 5-HT1A agonists LY165163 and 8-OH-DPAT in the rat is not dependent on presynaptic 5-HT stores and is therefore probably mediated by postsynaptic 5-HT receptors.
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003891:Desipramine / Q000494:pharmacology; D010134:Fenclonine / Q000494:pharmacology; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology*; D009627:Nomifensine / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D009281:Naphthalenes; D010879:Piperazines; D013764:Tetrahydronaphthalenes; D009627:Nomifensine; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C044643:LY 165163; D010134:Fenclonine; D003891:Desipramine