The melanocortin system is composed of the melanocortin peptides, adrenocorticotropic hormone and alpha-, beta-, and gamma-melanocyte-stimulating hormone, the melanocortin receptors (MCRs), and the endogenous antagonists agouti- and agouti-related protein. Melanocortin peptides exert multiple effects upon the host, including anti-inflammatory and immunomodulatory effects. Leukocytes are a sourc...

alpha-melanocyte stimulating hormone (alpha-MSH), a peptide that occurs within the brain, the circulation, and other body sites, is a potent antipyretic agent when given centrally or peripherally. The peptide likewise inhibits inflammation and aspects of the acute-phase response. The combined evidence suggests that alpha-MSH molecules act as natural modulators of host reactions by antagonizing ...