| Literature DB >> 17321768 |
Tetsuya Tachibana1, Daichi Oikawa, Hirokazu Takahashi, Tim Boswell, Mitsuhiro Furuse.
Abstract
Alpha-melanocyte-stimulating hormone (alpha-MSH) is recognized as an anorexic peptide in the brain of vertebrates, but its mechanism of action has not been identified in birds. Therefore, we investigated whether the anorexic effect of alpha-MSH is mediated by corticotrophin-releasing factor (CRF) in the domestic chick. Firstly, we found that intracerebroventricular (i.c.v.) injection of alpha-MSH dose dependently increased plasma corticosterone (CORT) concentration. This effect was partly attenuated by co-injection of astressin, a CRF receptor antagonist, demonstrating that alpha-MSH stimulated CORT secretion by activating CRF neurons. The alpha-MSH-elicited CORT release was not attenuated by the injection of agouti-related protein, an endogenous melanocortin-4 (MC4) receptor antagonist, suggesting that alpha-MSH stimulated CRF neurons through MC4 receptor-independent pathways. Finally, we found that the anorexic effect of alpha-MSH was partly attenuated by astressin. The present results suggest that the anorexic effect of alpha-MSH in the chick brain is mediated in part by activation of CRF neurons.Entities:
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Year: 2007 PMID： 17321768 DOI： 10.1016/j.cbpa.2006.12.044
Source DB: PubMed Journal: Comp Biochem Physiol A Mol Integr Physiol ISSN： 1095-6433 Impact factor: 2.320