title: The effect of melanocortin (Mc3 and Mc4) antagonists on serotonin-induced food and water intake of broiler cockerels.
abstract: The current study was designed to examine the effects of intracerebroventricular injections of SHU9119 [a nonselective melanocortin receptor (McR) antagonist] and MCL0020 (a selective McR antagonist) on the serotonin-induced eating and drinking responses of broiler cockerels deprived of food for 24 h (FD24). For Experiment 1, the chickens were intracerebroventricularly injected with 2.5, 5, and 10 µg serotonin. In Experiment 2, the chickens received 2 nmol SHU9119 before being injected with 10 µg serotonin. For Experiment 3, the chickens were given 10 µg serotonin after receiving 2 nmol MCL0020, and the level of food and water intake was determined 3 h post-injection. Results of this study showed that serotonin decreased food intake but increased water intake among the FD24 broiler cockerels and that these effects occurred in a dose-dependent manner. The inhibitory effect of serotonin on food intake was significantly attenuated by pretreatment with SHU9119 and MCL0020. However, the stimulatory effect of serotonin on water intake was not altered by this pretreatment. These results suggest that serotonin hypophagia and hyperdipsia were mediated by different mechanisms in the central nervous system, and that serotonin required downstream activation of McRs to promote hypophagia but not hyperdipsia in the FD24 chickens.
authors.affiliation: Section of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, P.O. Box 14155-6453 Tehran, Iran. zendedel@ut.ac.ir
authors.forename: Morteza
authors.initials: M
authors.lastname: Zendehdel
authors.forename: Farshid
authors.initials: F
authors.lastname: Hamidi
authors.forename: Vahab
authors.initials: V
authors.lastname: Babapour
authors.forename: Kasra
authors.initials: K
authors.lastname: Mokhtarpouriani
authors.forename: Ramin Mazaheri Nezhad
authors.initials: RM
authors.lastname: Fard
mesh_terms: D000818:Animals; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D005508:Food Deprivation; D007276:Injections, Intraventricular / Q000662:veterinary; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*; D044104:Receptor, Melanocortin, Type 3 / Q000037:antagonists & inhibitors*; D044105:Receptor, Melanocortin, Type 4 / Q000037:antagonists & inhibitors*; D012701:Serotonin / Q000494:pharmacology
chemical_list: C484906:Ac-D-2Nal-Arg-2Nal-NH2; D009842:Oligopeptides; D044104:Receptor, Melanocortin, Type 3; D044105:Receptor, Melanocortin, Type 4; C103272:SHU 9119; D012701:Serotonin; D009074:Melanocyte-Stimulating Hormones