Alpha-melanocyte stimulating hormone plays an important role in the regulation of food intake by the central melanocortin system in chicks.

摘要

Proopiomelanocortin (POMC, a precursor of melanocortin peptides) neurons in the hypothalamus play an important role in the central regulation of food intake in mammals. There is evidence that human melanocortin peptides alpha-, beta- and gamma2-melanocyte-stimulating hormone (alpha-, beta- and gamma2-MSH) significantly decreased food intake in chickens. However, the amino acid sequences of beta- and gamma2-MSH of chickens are different from those of humans whereas the amino acid sequence of alpha-MSH is conserved between these species. In the present study, we examined the effects of the central administration of alpha-, chicken beta-, and chicken gamma2-MSH on food intake in chicks. Central administration of alpha-MSH significantly suppressed food intake in chicks. In contrast, beta- and gamma2-MSH did not influence food intake in chicks. Central administration of HS014, a melanocortin 4 receptor antagonist, significantly reversed the anorexigenic action of alpha-MSH, suggesting that this action is mediated by the melanocortin 4 receptor in chicks as well as in mammals. These results suggest that alpha-MSH may play an important role in the regulation of food intake by the central melanocortin system in chicks.