BRAIN MELANOCORTIN RECEPTORS - FROM CLONING TO FUNCTION

The cloning of brain melanocortin (MC) receptors, the mapping of their expression pattern and the identification of MC receptor selective li gands have opened a new avenue towards elucidating the role of the mel anocortin system in the brain. MC receptors have now been implicated i n melanocortin induced grooming behavior in rats, in the melanocortin- induced lowering of blood pressure and in the control of weight homeos tasis. Functional opioid antagonism and the anti-pyretic and anti-infl ammatory effects of melanocortins are probably also mediated via MC re ceptors. However, the effects of melanocortins on avoidance behavior a nd the effect of gamma(2)-MSH on increasing blood pressure are not med iated via one of the cloned brain MC receptors. The structure of brain MC receptors, their expression pattern, the MC receptor selective lig ands and the function of MC receptors are briefly reviewed. (C) 1997 E lsevier Science Inc.