Melanocortin system

Cone RD (2006) Studies on the physiological functions of the melanocortin system. EndocrRev 27 736-749... 

Seeley RJ, Drazen DL, Clegg DJ. The critical role of the melanocortin system in the control of energy balance. Annu Rev Nutr. 2004 24 133-149. 

Mahogany, a single-pass transmembrane protein that modulates the activity of agouti protein and agouti-related protein (AGRP). It is an ancillary protein of the melanocortin system. Mahogany is expressed primarily in the brain, especially in the hypothalamus, and in the skin. It is involved in mammalian coat coloration [T. M. Gunn et al.. Nature 1999, 398, 152]. 

Melanocortin system (MCS), a complex physiological system involved in pigmentation, inflammation, steroidogenesis, en-... 

Several multi-ligand/multi-receptor systems are known in which multiple structurally related peptide hgands bind to various GPCRs that belong to a common receptor family. The neuropeptide Y family, the tachykinin system and the melanocortin system, just to mention a few, are known to exhibit important functions in the organism and therefore have been intensively investigated for years by SAR studies based on synthetically derived analogs. 

MC3R is expressed both within the periphery and central nervous system (CNS) with detection in immune cells, gut, placenta but no detection in the adrenal gland or melanocytes. Unlike other MCR, most melanocortins (ACTHi 39, a-, (3- and y-MSH) display equipotent binding and full biological activity with truncated peptides, ACTH o and ACTH o MC3R... 

Vrinten DH, Gispen WH, Kalkman CJ, Adan RA. Interaction between the spinal melanocortin and opioid systems in a rat model of neuropathic pain. Anesthesiology. 2003 99 449-454. 

Tritos, N. A. and E. Maratos-Flier (1999). Two important systems in energy homeostasis melanocortins and melanin-concentrating hormone. Neuropeptides 33(5) 339-49. 

Hanada R, Nakazato M. Matsukura S, Murakami N, Yoshimatsu H. Sakata T. Differential regulation of melanin-concentrating hormone and orexin genes in the agouti-related protein/melanocortin-4 receptor system. Biochem Biophys Res Commun 2000 268 88-91. 

The corticosteroid secretory regions of the adrenal gland express the mRNA for the ACTH receptor but not for the MSH receptor. In murine melanoma, on the other hand, it is the mRNA for MSH that is expressed. As melanocortins in the nervous system and immune system differ from each other and from receptors on adrenocortical cells and melanocytes (De Wied and Jolles, 1982 Cannon et al., 1986 Tatro and Reichlin, 1987 Ta-... 

Hughes and Smith, 1988, 1989a, 1991). These observations fit well with the comparable restriction of beneficial melanocortin activity to the developing, regenerating or metabolically disturbed nerve and muscle. Melanocortins have little discernible influence upon the adult, healthy neuromuscular system. 

Once again, the critical period of sensitivity to melanocortins is illustrated, although there may be an additional factor to be considered, i.e. that the postnatal serotonergic system may be more vulnerable to changes in its hormonal environment when the placenta no longer acts as a selective barrier. 

The improvement in regrowth is reflected in the improved electrophysiological parameters of the EDL muscle in the melanocortin-treated, injured neonates. Many of the contractile parameters of both the twitch and tetanus are in the normal range force amplitude, contraction rate, halfrelaxation time, post-tetanic twitch amplitude, and rate of rise (Zuccarelli and Strand, 1992). Of considerable significance is that a-MSH also increases the number of motor units, presumably restoring fine motor control in the traumatized, developing neuromuscular system. 

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