Effect of some serotoninergic agents on the rectal temperature of the domestic fowl (Gallus domesticus).
The information currently available in the literature on the effects of serotonergic drugs on thermoregulation in the avian species is very scanty. Therefore, it was the objective in this project to study the influence of 5-hydroxytryptamine (5-HT), 5-hydroxytryptophan (5-HTP), benserazide, carbidopa (Mk 486), citalopram, cyproheptadine, methysergide, xylamidine, p-chlorophenylalanine (PCPA) and lysergic acid diethylamide (LSD-25) on the rectal temperature of young chicks. 5-hydroxytryptamine (0.8 mg/kg), produced significant dose-dependent hypothermia in young chicks. Similarly, 5-HTP (16 mg/kg) profoundly lowered the rectal temperature of young chicks. The hypothermic effect of 5-HTP was potentiated by benserazide (1.25-2.5 mg/kg). Pretreatment with carbidopa (50 mg/kg) potentiated 5-HTP induced hypothermia. Citalopram (5 mg/kg) significantly potentiated hypothermia induced by 5-HT. Pretreatment with PCPA (200 mg/kg, 24 hr previously) alone resulted in hyperthermia while the hypothermic effect of 5-HTP (16 mg/kg) was antagonised by pretreatment with PCPA. Cyproheptadine (1.25 mg/kg) antagonised the hypothermic effect of 5-HT (0.1 and 0.8 mg/kg). The antagonistic effect was weak when the chicks were pretreated with larger doses of cyproheptadine (i.e. 2.5-10 mg/kg). The hypothermia induced by 5-HT (0.8 mg/kg) was antagonised by smaller doses of methysergide (0.125-1.0 mg/kg) but potentiated by larger doses of methysergide (2.0 and 4.0 mg/kg). Xylamidine (1-2 mg/kg) alone induced hyperthermia and effectively antagonised hypothermia induced by 5-HT (0.8 mg/kg). D-Lysergic acid diethylamide (2.5-10 micrograms/kg) alone induced hypothermia. The interaction between LSD and 5-HT was dose-dependent and biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D001545:Benserazide / Q000494:pharmacology; D001831:Body Temperature / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects; D002230:Carbidopa / Q000494:pharmacology; D002417:Cattle; D002645:Chickens; D015283:Citalopram; D003533:Cyproheptadine / Q000494:pharmacology; D010134:Fenclonine / Q000494:pharmacology; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D011437:Propylamines / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D013997:Time Factors
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D011437:Propylamines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D015283:Citalopram; D003533:Cyproheptadine; D012701:Serotonin; D001545:Benserazide; D008238:Lysergic Acid Diethylamide; D006916:5-Hydroxytryptophan; D002230:Carbidopa; D010134:Fenclonine; D008784:Methysergide