Melanocyte stimulating hormones

Endorphin (143) is produced from pto-opiomelanocottin, a precursor for a-, P-, and y-melanocyte stimulating hormones (MSH), adtenocorticotropin (ACTH), which includes the a-MSH sequence, and P-Hpotropin (P-LPH), which includes P-MSH and P-endotphin sequences. 

CART (cocaine- and amphetamine-regulated transcript) is a hypothalamic peptide that inhibits both normal and starvation-induced feeding when injected into cerebral ventricles of rats. CART is co-localized with the anorexigenic peptide a-melanocyte-stimulating hormone in neurons of the arcuate nucleus. Secretion of CART is stimulated by leptin and CART may be an endogenous inhibitor of food intake. 

Proopiomelanocortin (POMC) is the precursor peptide of hormones and neuropeptides expressed in the pituitary and the hypothalamus (adrenocorticotropic hormone (ACTH), lipotropin, a-melanocyte-stimulating hormone (aMSH), yMSH, 3-endorphin, and others). The main clinical consequences of POMC deficiency are adrenal insufficiency (due to absence of ACTH), red hair pigmentation (due to absence of MSH) and severe early-onset obesity (due to the lack of aMSH). 

Johansson O, Ljungberg A, Han SW, Vaalasti A (1991) Evidence for gamma-melanocyte stimulating hormone containing nerves and neutrophilic gran-... 

Luteinizing hormone Melanocyte-stimulating hormone Parathyroid hormone Somatostatin... 

Figure 42-15. Products of pro-opiomelanocortin (POMQ cleavage. (MSH, melanocyte-stimulating hormone CLIP, corticotropin-like intermediate lobe peptide LPH, lipotropin.)...

M. Tsatmali, A. Graham, D. Szatkowski, J. Ancans, P. Manning, C.J. McNeil, A.M. Graham, and A.J. Thody, Alpha-melanocyte-stimulating hormone modulates nitric oxide production in melanocytes. 

FIGURE 1 8-5 Tissue-specific processing of the pro-opiomelanocortin (POMC) precursor yields a wide array of bioactive peptide products. Processing of the POMC precursor varies in various tissues. In anterior pituitary, adrenocorticotropic hormone (ACTH (1-39)) and P-1 ipo tropin (P-LPH) are the primary products of post-translational processing. Arcuate neurons produce the potent opiate P-endorphin (P-endo (1-31)) as well as ACTIK1 -13) NIT,. Intermediate pituitary produces a-melanocyte-stimulating hormone (aMSH), acetylated P endof 1 31) and P-endo(l-27). NTS, nucleus tractus solitarius. 

FIGURE 18-7 Processing of the proopiomelanocortin (POMC) precursor proceeds in an ordered, stepwise fashion. Cleavage of the POMC precursor occurs at seven sites, with some of the reactions being tissue-specific. The circled numbers indicate the temporal order of cleavage in tissues where these proteolytic events occur. ACTH, adrenocorticotropic hormone CLIP, corticotropin-like intermediate lobe peptide JP, joining peptide LPH, lipotropin MSH, melanocyte-stimulating hormone PC, prohormone convertase. 

KRP kinesin related protein ocMSH oc-melanocyte-stimulating hormone... 

Hyperpigmentation is common in Addison s disease and may involve exposed and nonexposed parts of the body. Hyperpigmentation is usually not seen in secondary adrenal insufficiency because of low amounts of melanocyte-stimulating hormone. 

Bohm, M. et al., Alpha-melanocyte-stimulating hormone protects from ultraviolet radiation-induced apoptosis and DNA damage, J. Biol. Chem. 280, 5795-5802, 2005. 

Grabbe, S. et al., a-Melanocyte-stimulating hormone induces hapten-specific tolerance in mice, J. Immunol. 156, 473 178, 1996. 

Burton, J.L., Shuster, S., Cartlidge, M., Libman, L.J., and Martell, U. (1973). Lactation, sebum excretion and melanocyte-stimulating hormone. Nature 243, 349-350. 

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