Central administration of neuromedin U suppresses food intake in chicks

The appetite-suppressive action of brain–gut peptides is similar in both chickens and mammals. In mammals, the brain–gut peptide neuromedin U (NMU) suppresses food intake via hypothalamic neuropeptides, corticotropin-releasing factor (CRF), oxytocin, and arginine–vasopressin. In chickens, central administration of CRF, oxytocin, or arginine–vasotocin (AVT, a nonmammalian equivalent of arginine–vasopressin) suppresses food intake. However, the anorexigenic action of NMU in chickens has not yet been identified. In the present study, we analyzed the effects of the central administration of NMU on food intake and hypothalamic mRNA levels of CRF, AVT and mesotocin (a nonmammalian equivalent of oxytocin) in chicks. Intracerebroventricular administration of NMU in chicks significantly suppressed food intake and induced wing-flapping behavior. NMU also significantly upregulated mRNA expression of CRF and AVT, but did not influence mRNA expression of mesotocin in the hypothalamus. These results suggest that NMU functions as an appetite-suppressive peptide via CRF and AVT in the central nervous system in chicks.