melanotropin

• メラニン細胞刺激ホルモン

関

intermedin、melanocyte-stimulating hormone、MSH

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/12/15 12:57:14」(JST)

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pro-opiomelanocortin
Identifiers
Symbol	POMC
Entrez	5443
HUGO	9201
OMIM	176830
RefSeq	NM_000939
UniProt	P01189
Other data
Locus	Chr. 2 p23

Melanocyte-stimulating hormone

Identifiers
ChemSpider	none
ChEMBL	CHEMBL214332 N
NY (what is this?)  (verify)

The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the intermediate lobe of the pituitary gland.

Synthetic analogues of α-MSH, such as afamelanotide (melanotan I; Scenesse), melanotan II, and bremelanotide (PT-141), have been developed and researched.

Function

MSH stimulate the production and release of melanin (a process referred to as melanogenesis) by melanocytes in skin and hair. MSH actions in the brain have effects on appetite and sexual arousal.

In amphibians

In some animals (such as the claw-toed frog Xenopus laevis) production of MSH is increased when the animal is in a dark location. This causes pigment to be dispersed in pigment cells in the toad's skin, making it become darker, and harder for predators to spot. The pigment cells are called melanophores and therefore, in amphibians, the hormone is often called melanophore-stimulating hormone.

In humans

See also: Melanocortin receptor

An increase in MSH will cause darker skin in humans too. MSH increases in humans during pregnancy. This, along with increased estrogens, causes increased pigmentation in pregnant women. Cushing's disease due to excess adrenocorticotropic hormone (ACTH) may also result in hyperpigmentation, such as acanthosis nigricans in the axilla. Most people with primary Addison's disease have darkening (hyperpigmentation) of the skin, including areas not exposed to the sun; characteristic sites are skin creases (e.g. of the hands), nipple, and the inside of the cheek (buccal mucosa), new scars become hyperpigmented, whereas older ones do not darken. This occurs because MSH and ACTH share the same precursor molecule, proopiomelanocortin (POMC).

Different levels of MSH are not the major cause of racial variation in skin colour. However, in many red-headed people, and other people who do not tan well, there are variations in their hormone receptors, causing them to not respond to MSH in the blood.

Structure of MSH

proopiomelanocortin derivatives
POMC
γ-MSH	ACTH		β-lipotropin
	α-MSH	CLIP	γ-lipotropin		β-endorphin
				β-MSH

The different forms of MSH belong to a group called the melanocortins. This group includes ACTH, α-MSH, β-MSH, and γ-MSH; these peptides are all cleavage products of a large precursor peptide called proopiomelanocortin (POMC). α-MSH is the most important melanocortin for pigmentation.

The different forms of MSH have the following amino acid sequences:

α-MSH:	Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val
β-MSH (human):	Ala-Glu-Lys-Lys-Asp-Glu-Gly-Pro-Tyr-Arg-Met-Glu-His-Phe-Arg-Trp-Gly-Ser-Pro-Pro-Lys-Asp
β-MSH (porcine):	Asp-Glu-Gly-Pro-Tyr-Lys-Met-Glu-His-Phe-Arg-Trp-Gly-Ser-Pro-Pro-Lys-Asp
γ-MSH:	Tyr-Val-Met-Gly-His-Phe-Arg-Trp-Asp-Arg-Phe-Gly

Synthetic MSH

Synthetic analogues of α-MSH have been developed for human use. Two of the better known are afamelanotide (melanotan I) in testing by Clinuvel Pharmaceuticals and bremelanotide by Palatin Technologies. Others include modimelanotide and setmelanotide.

• Afamelanotide (brand name Scenesse) has been approved for the treatment of erythropoietic protoporphyria in Europe and is also being investigated as a method of photoprotection in the treatment of polymorphous light eruption, actinic keratosis and squamous cell carcinoma (a form of skin cancer).
• An additional analogue called melanotan II causes enhanced libido and erections in most male test subjects and arousal with corresponding genital involvement in most female test subjects. Bremelanotide (formerly PT-141) which stemmed from melanotan II research is currently under development for its aphrodisiac effects. These effects are mediated by actions in the hypothalamus on neurons that express MC₃ and MC₄ receptors.

See also

• Melanocyte-inhibiting factor
• Agouti-related peptide
• Agouti signalling peptide
• Nelson's syndrome

References

Further reading

• Millington GW (May 2006). "Proopiomelanocortin (POMC): the cutaneous roles of its melanocortin products and receptors". Clin. Exp. Dermatol. 31 (3): 407–12. doi:10.1111/j.1365-2230.2006.02128.x. PMID 16681590. 
• Millington GW (2007). "The role of proopiomelanocortin (POMC) neurones in feeding behaviour". Nutr Metab (Lond). 4: 18. doi:10.1186/1743-7075-4-18. PMC 2018708. PMID 17764572. 

External links

• Melanocyte-Stimulating Hormones at the US National Library of Medicine Medical Subject Headings (MeSH)
• Clinuvel Pharmaceuticals
• Palatin Technologies

English Journal

• Systematic Backbone Conformational Constraints on a Cyclic Melanotropin Ligand Leads to Highly Selective Ligands for Multiple Melanocortin Receptors.

• Cai M1, Marelli UK2, Bao J1, Beck JG2, Opperer F2, Rechenmacher F2, McLeod KR1, Zingsheim MR1, Doedens L2, Kessler H2,3, Hruby VJ1.
• Journal of medicinal chemistry.J Med Chem.2015 Aug 27;58(16):6359-67. doi: 10.1021/acs.jmedchem.5b00102. Epub 2015 Aug 11.
• Human melanocortin receptors (hMCRs) have been challenging targets to develop ligands that are explicitly selective for each of their subtypes. To modulate the conformational preferences of the melanocortin ligands and improve the biofunctional agonist/antagonist activities and selectivities, we hav
• PMID 26218460

• Afamelanotide for Erythropoietic Protoporphyria.

• Langendonk JG1, Balwani M, Anderson KE, Bonkovsky HL, Anstey AV, Bissell DM, Bloomer J, Edwards C, Neumann NJ, Parker C, Phillips JD, Lim HW, Hamzavi I, Deybach JC, Kauppinen R, Rhodes LE, Frank J, Murphy GM, Karstens FP, Sijbrands EJ, de Rooij FW, Lebwohl M, Naik H, Goding CR, Wilson JH, Desnick RJ.
• The New England journal of medicine.N Engl J Med.2015 Jul 2;373(1):48-59. doi: 10.1056/NEJMoa1411481.
• BACKGROUND: Erythropoietic protoporphyria is a severe photodermatosis that is associated with acute phototoxicity. Patients with this condition have excruciating pain and a markedly reduced quality of life. We evaluated the safety and efficacy of an α-melanocyte-stimulating hormone analogue, afamel
• PMID 26132941

• Increased corticotropin-releasing hormone (CRH) expression in cutaneous lupus lesions.

• Schmitz MK1, Botte DA1, Sotto MN2, Borba EF1, Bonfa E1, de Mello SB3.
• Lupus.Lupus.2015 Jul;24(8):854-61. doi: 10.1177/0961203315569335. Epub 2015 Jan 28.
• OBJECTIVE: Corticotropin-releasing hormone (CRH) and pro-opiomelanocortin (POMC) axis activation leads to the production of hormones, such as adrenocorticotrophic hormone (ACTH) and the α-melanocyte stimulating hormone (α-MSH). Data regarding the role of these hormones in systemic lupus erythemato
• PMID 25634068

Japanese Journal

• Mass spectrometric detection of proopiomelanocortin (POMC)-related peptides following molecular cloning of POMC cDNA in bigeye tuna Thunnus obesus

• Takahashi Akiyoshi,Amemiya Yutaka,Yasuda Akikazu [他],MEGURO Hiroshi,KAWAUCHI Hiroshi
• Fisheries science : FS 68(5), 1073-1080, 2002-10-01
• NAID 10009716795

• Glycoconjugate Profiles of Adrenocorticotropic and Melanotropic Cells in the Pituitary of Adult Sea Lampreys (Petromyzon marinus) : A Lectin Histochemical Study(Endocrinology)

• Ominato Kunihiro,Nozaki Masumi
• Zoological science 19(7), 773-779, 2002-07-25
• In the lamprey, adrenocorticotropin (ACTH) and melanotropins (MSHs) are produced from two distinct precursors, proopiocortin (POC) and proopiomelanotropin (POM). Both POC and POM have been suggested t …
• NAID 110003372781

• Mass spectrometric detection of proopiomelanocortin(POMC)-related peptides following molecular cloning of POMC cDNA in bigeye tuna Thunnus obesus.

• , , , ,
• Fisheries science 68(5), 1073-1080, 2002
• … Several pituitary hormones, including adrenocorticotropin (ACTH), melanotropin (MSH) and β-endorphin, are generated from a common precursor protein, proopiomelanocortin (POMC). …
• NAID 130003742476

Related Links

• Melanotropin receptor - Wikipedia, the free encyclopedia

Melanotropin receptor is a protein found in skin and eye cells that make melanin ( a pigment that gives color to the skin and helps protect it from damage by ultraviolet light). People with certain changes in the gene for the melanotropin receptor ...

Related Pictures

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★リンクテーブル★

リンク元	「メラニン細胞刺激ホルモン」「intermedin」

「メラニン細胞刺激ホルモン」

　　[★]

英

melanocyte-stimulating hormone melanocyte stimulating hormone, MSH

同

メラノトロピン melanotropin

関

• 主にプロオピオメラノコルチン(POMC)が元となって生成される。

• 1. α-MSH：副腎皮質刺激ホルモン(ACTH) = α-MSH + corticotropin-like intermediate lobe peptide(CLIP)
• 2. β-MSH：γリポトロピン(γ-LPH)(ヒト、ラット、マウスには存在しないらしい)
• 3. γ-MSH：POMCのN末端部分(MSH作用は弱いらしい)

「intermedin」

　　[★]

インターメジン、メラニン細胞刺激ホルモン

関

melanocyte-stimulating hormone、melanotropin、MSH