WordNet

the secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect (同)endocrine, internal_secretion
rousing or quickening activity or the senses; "a stimulating discussion"
a cell in the basal layer of the epidermis that produces melanin under the control of the melanocyte-stimulating hormone

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ホルモン
刺激する;激励する,元気づける

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/06/15 09:54:54」(JST)

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The melanocyte-stimulating hormones (collectively referred to as MSH or intermedins) are a class of peptide hormones that are produced by cells in the intermediate lobe of the pituitary gland. Synthetic analogs of these naturally occurring hormones have also been developed and researched.

Function[edit]

They stimulate the production and release of melanin (melanogenesis) by melanocytes in skin and hair. MSH signals to the brain have effects on appetite and sexual arousal.

In amphibians[edit]

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[edit]

An increase in MSH will cause a darkening in humans too. Melanocyte-stimulating hormone increases in humans during pregnancy. This, along with increased estrogens, causes increased pigmentation in pregnant women. Cushing's syndrome due to excess adrenocorticotropic hormone (ACTH) may also result in hyperpigmentation, such as acanthosis nigricans in the axilla. Most people with primary Addison's 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 melanocyte-stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH) share the same precursor molecule, Pro-opiomelanocortin (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.

See melanocortin receptor for more information.

Structure of MSH[edit]

Melanocyte-stimulating hormone belongs to a group called the melanocortins. This group includes ACTH, alpha-melanocyte-stimulating hormone (α-MSH), beta-melanocyte-stimulating hormone (β-MSH) and gamma-melanocyte-stimulating hormone (γ-MSH); these peptides are all cleavage products of a large precursor peptide called pro-opiomelanocortin (POMC). α-MSH is the most important melanocortin for pigmentation.

The different melanocyte-stimulating hormones 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[edit]

Synthetic analogs of α-MSH have been developed for human use. Two of the better known are afamelanotide (melanotan-1) in testing by Clinuvel Pharmaceuticals in Australia and bremelanotide by Palatin Technologies, a New Jersey company.

Afamelanotide (formerly CUV1647) is being investigated as a method of photoprotection in patients with erythropoietic protoporphyria, polymorphous light eruption, actinic keratosis and squamous cell carcinoma (a form of skin cancer).^[1]

An additional analog called Melanotan II causes enhanced libido and erections in most male test subject and arousal with corresponding genital involvement in most female test subjects.^[2] Bremelanotide (formerly PT-141) which stemmed from Melanotan II research is currently under development by a New Jersey company for its aphrodisiac effects. These effects are mediated by actions in the hypothalamus on neurons that express MC3R and MC4R receptors.

References[edit]

^ Clinuvel FAQs
^ Hadley ME (Oct 2005). "Discovery that a melanocortin regulates sexual functions in male and female humans". Peptides 26 (10): 1687–9. doi:10.1016/j.peptides.2005.01.023. PMID 15996790.

External links[edit]

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

UpToDate Contents

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1. 成人における副腎不全の臨床症状 clinical manifestations of adrenal insufficiency in adults
2. ACTH、CRH、および他の視床下部／下垂体ペプチドの測定 measurement of acth crh and other hypothalamic and pituitary peptides
3. レプチンの生理学 physiology of leptin
4. 内臓悪性腫瘍の皮膚症状 cutaneous manifestations of internal malignancy
5. 黒色腫（メラノーマ）の分子生物学 the molecular biology of melanoma

English Journal

β-Cryptoxanthin suppresses UVB-induced melanogenesis in mouse: involvement of the inhibition of prostaglandin E(2) and melanocyte-stimulating hormone pathways.

Shimoda H, Shan SJ, Tanaka J, Maoka T.SourceResearch & Development Division, Oryza Oil & Fat Chemical Co., Ltd, Ichinomiya, Aichi Research Institute for Production Development, Sakyo-ku, Kyoto, Japan.
The Journal of pharmacy and pharmacology.J Pharm Pharmacol.2012 Aug;64(8):1165-76. doi: 10.1111/j.2042-7158.2012.01495.x. Epub 2012 Mar 27.
Objective β-cryptoxanthin (β-CPX) is a carotenoid that is widely contained in the fruits of citrus plants. We evaluated the effect of β-CPX on UVB-induced pigmentation and mRNA expression related to melanogenesis in mouse skin. In addition, changes in melanogenic molecules were evaluated in cu
PMID 22775220

Selected melanocortin 1 receptor single-nucleotide polymorphisms differentially alter multiple signaling pathways.

Doyle JR, Fortin JP, Beinborn M, Kopin AS.SourceTufts Medical Center, 800 Washington Street, P.O. Box 7703, Boston, MA 02111. akopin@tuftsmedicalcenter.org.
The Journal of pharmacology and experimental therapeutics.J Pharmacol Exp Ther.2012 Aug;342(2):318-26. Epub 2012 Apr 30.
The melanocortin 1 receptor (MC1R) is a highly polymorphic G protein-coupled receptor, which is known to modulate pigmentation and inflammation. In the current study, we investigated the pharmacological effects of select single-nucleotide polymorphisms (SNPs) (V60L, R163Q, and F196L). After transien
PMID 22547573

Japanese Journal

コイおよびキンギョ脳下垂体におけるトリアセチルα-黒色素胞刺激ホルモンの同定

安田明和,茂里康
比較内分泌学 38(145), 90-93, 2012-05-00
NAID 40019336812

trans-Caffeic Acid Stearyl Ester from Paeonia suffruticosa Inhibits Melanin Synthesis by cAMP-Mediating Down-Regulation of α-Melanocyte-Stimulating Hormone-Stimulated Melanogenesis Signaling Pathway in B16 Cells

Liang Chia-Hua,Chou Tzung-Han,Tseng Ya-Ping [他],Ding Hsiou-Yu
Biological and Pharmaceutical Bulletin 35(12), 2198-2203, 2012
… TCASE considerably inhibits melanin synthesis, and reduces intracellular cyclic adenosine monophosphate (cAMP) levels, tyrosinase activity and L-3-(3,4-dihydroxyphenyl)-alanine (DOPA) oxidase activity in a concentration-dependent manner in the presence of α-melanocyte-stimulating hormone (α-MSH) in B16 cells, and the inhibition efficiency of TCASE exceeds that of ascorbic acid and arbutin. …
NAID 130002480511

Inhibitory Effects of Morinda citrifolia Extract and Its Constituents on Melanogenesis in Murine B16 Melanoma Cells

Masuda Megumi,Itoh Kimihisa,Murata Kazuya [他],Naruto Shunsuke,Uwaya Akemi,Isami Fumiyuki,Matsuda Hideaki
Biological and Pharmaceutical Bulletin 35(1), 78-83, 2012
… The objective of this study was to examine the effects of Morinda citrifolia (noni) extract and its constituents on α-melanocyte stimulating hormone (α-MSH)-stimulated melanogenesis in cultured murine B16 melanoma cells (B16 cells). …
NAID 130001872346

Related Pictures

★リンクテーブル★

リンク元	「メラニン細胞刺激ホルモン」「intermedin」「melanotropin」「MSH」
拡張検索	「alpha-melanocyte-stimulating hormone」「gamma-melanocyte-stimulating hormone」
関連記事	「stimulating」