gonadotrophin

ゴナドトロピン、性腺刺激ホルモン、ゴナドトロフィン

関

gonadotropic hormone、gonadotropin、GTH

WordNet

1. hormone secreted by the anterior pituitary gland and placenta; stimulates the gonads and controls reproductive activity (同)gonadotrophin, gonadotropic_hormone, gonadotrophic hormone

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/11/10 18:51:55」(JST)

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Glycoprotein hormone
Identifiers
Symbol	Hormone_6
Pfam	PF00236
InterPro	IPR000476
PROSITE	PDOC00623
SCOP	1hcn
SUPERFAMILY	1hcn
OPM protein	1fl7
Available protein structures: Pfam structures PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

Gonadotropins are glycoprotein polypeptide hormones secreted by gonadotrope cells of the anterior pituitary of vertebrates. This family includes the mammalian hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), and placental/chorionic gonadotropins human chorionic gonadotropin (hCG) and equine chorionic gonadotropin (eCG), as well as at least two forms of fish gonadotropins. These hormones are central to the complex endocrine system that regulates normal growth, sexual development, and reproductive function. LH and FSH are secreted by the anterior pituitary gland, while hCG and eCG are secreted by the placenta in pregnant humans and mares, respectively. The gonadotropins act on the gonads, controlling gamete and sex hormone production.

Gonadotropin is sometimes abbreviated Gn. The alternative spelling gonadotrophin which inaccurately implies a nourishing mechanism is still sporadically used.

Natural types and subunit structure

The two principal gonadotropins in vertebrates are luteinizing hormone (LH) and follicle-stimulating hormone (FSH), although primates produce a third gonadotropin called chorionic gonadotropin (CG). LH and FSH are heterodimers consisting of two peptide chains, an alpha chain and a beta chain. LH and FSH share nearly identical alpha chains (about 100 amino acids long), whereas the beta chain provides specificity for receptor interactions. These subunits are heavily modified by glycosylation.

The alpha subunit is common to each protein dimer (well conserved within species, but differing between them), and a unique beta subunit, which confers biological specificity. The alpha chains are highly conserved proteins of about 100 amino acid residues which contain ten conserved cysteines all involved in disulfide bonds, as shown in the following schematic representation.

                       +---------------------------+
           +----------+|             +-------------|--+
           |          ||             |             |  |
       xxxxCxCxxxxxxCxCCxxxxxxxxxxxxxCCxxxxxxxxxxCxCxxCx
             |      |                 |          |
             +------|-----------------+          |
                    |                            |
                    +----------------------------+

'C': conserved cysteine involved in a disulphide bond.

Intracellular levels of free alpha subunits are greater than those of the mature glycoprotein, implying that hormone assembly is limited by the appearance of the specific beta subunits, and hence that synthesis of alpha and beta is independently regulated.

Another human gonadotropin is human chorionic gonadotropin (hCG), produced by the placenta during pregnancy.

Mechanism

gonadotropin-releasing hormone

Gonadotropin receptors are embedded in the surface of the target cell membranes and coupled to the G-protein system. Signals triggered by binding to the receptor are relayed within the cells by the cyclic AMP second messenger system.

Gonadotropins are released under the control of gonadotropin-releasing hormone (GnRH) from the arcuate nucleus and preoptic area of the hypothalamus. The gonads — testes and ovaries — are the primary target organs for LH and FSH. The gonadotropins affect multiple cell types and elicit multiple responses from the target organs. As a simplified generalization, LH stimulates the Leydig cells of the testes and the theca cells of the ovaries to produce testosterone (and indirectly estradiol), whereas FSH stimulates the spermatogenic tissue of the testes and the granulosa cells of ovarian follicles, as well as stimulating production of estrogen by the ovaries.

Although gonadotropins are secreted in a pulsatile manner (as a result of pulsatile GnRH release), unlike the case of GnRH and GnRH agonists, constant/non-pulsatile activation of the gonadotropin receptors by the gonadotropins does not produce functional inhibition. This can be seen during the first 7–10 weeks of pregnancy, where constantly high and progressively-increasing levels of hCG circulate and mediate production of estrogen and progesterone by the corpus luteum until the placenta takes over the production of these hormones.

Diseases

Gonadotropin deficiency due to pituitary disease results in hypogonadism, which can lead to infertility. Treatment includes administered gonadotropins, which, therefore, work as fertility medication. Such can either be produced by extraction and purification from urine or be produced by recombinant DNA.

Failure or loss of the gonads usually results in elevated levels of LH and FSH in the blood.

LH insensitivity, which results in Leydig cell hypoplasia in males, and FSH insensitivity, are conditions of insensitivity to LH and FSH, respectively, caused by loss-of-function mutations in their respective signaling receptors. Another closely related condition to these is GnRH insensitivity.

Pharmaceutical preparations

Main article: Gonadotropin preparations

There are various preparations of gonadotropins for therapeutic use, mainly as fertility medication. For example, the so-called menotropins (also called human menopausal gonadotropins) consist of LH and FSH extracted from the urine of menopausal women. There are also recombinant variants.

See also

• Antigonadotropin

References

External links

• Gonadotropins at the US National Library of Medicine Medical Subject Headings (MeSH)
• 10th International Symposium on GnRH

UpToDate Contents

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• 1. 性腺刺激ホルモン（ゴナドトロピン）放出ホルモンの生理学 physiology of gonadotropin releasing hormone
• 2. 排卵誘発の概要 overview of ovulation induction
• 3. 先天性性腺刺激ホルモン放出ホルモン欠乏症（特発性低ゴナドトロピン性性腺機能低下） congenital gonadotropin releasing hormone deficiency idiopathic hypogonadotropic hypogonadism
• 4. 女性の不妊症の治療の概要 overview of treatment of female infertility
• 5. Epidemiology and causes of secondary amenorrhea

English Journal

• Comparison of meat quality parameters in surgical castrated versus vaccinated against gonadotrophin-releasing factor male and female Iberian pigs reared in free-ranging conditions.

• Martinez-Macipe M1, Rodríguez P1, Izquierdo M2, Gispert M3, Manteca X4, Mainau E4, Hernández FI2, Claret A3, Guerrero L3, Dalmau A5.
• Meat science.Meat Sci.2016 Jan;111:116-21. doi: 10.1016/j.meatsci.2015.09.002. Epub 2015 Sep 11.
• PMID 26398005

• Novel homozygous deletion of segmental KAL1 and entire STS cause Kallmann syndrome and X-linked ichthyosis in a Chinese family.

• Xu H1, Li Z2, Wang T1, Wang S1, Liu J1, Wang DW2.
• Andrologia.Andrologia.2015 Dec;47(10):1160-5. doi: 10.1111/and.12397. Epub 2015 Jan 19.
• Kallmann syndrome (KS) is a genetically heterogeneous disease characterised by hypogonadotrophic hypogonadism in association with anosmia or hyposmia. This condition affects 1 in 10 000 men and 1 in 50 000 women. Defects in seventeen genes including KAL1 gene contribute to the molecular basis of K
• PMID 25597551

• Fertility Issues for Patients with Hypogonadotropic Causes of Delayed Puberty.

• Zhu J1, Chan YM2.
• Endocrinology and metabolism clinics of North America.Endocrinol Metab Clin North Am.2015 Dec;44(4):821-34. doi: 10.1016/j.ecl.2015.07.011. Epub 2015 Sep 10.
• Delayed puberty presenting with low gonadotropins has multiple causes. Self-limited delay (constitutional delay) is generally considered benign, but adult height and bone mineral density may be compromised, and fertility has not been studied. Functional hypogonadotropic hypogonadism due to a stresso
• PMID 26568495

Japanese Journal

• The Loss of Luteal Progesterone Production in Women Is Associated With a Galectin Switch via alpha 2,6-Sialylation of Glycoconjugates

• Journal of clinical endocrinology & metabolism 99(12), 4616-4624, 2014-12
• NAID 120005553690

• 生理食塩水に溶解したヒト閉経期性腺刺激ホルモンによるウシ過剰排卵処理の簡易化(第2報)

• 岡山県農林水産総合センター畜産研究所研究報告 = Bulletin of the Institute of Animal Production, Okayama Prefectural Technology Center for Agriculture, Forestry and Fisheries (3), 7-10, 2013-12
• NAID 40020062549

• A Three-day PGF₂α Plus eCG-based Fixed-time AI Protocol Improves Fertility Compared with Spontaneous Estrus in Dairy Cows with Silent Ovulation

• The Journal of reproduction and development 59(4), 393-397, 2013-08-01
• NAID 10031195877

Related Links

• gonadotrophin - definition of gonadotrophin by Medical dictionary

Gonadotrophin Hormones that stimulate the ovary and testicles. Mentioned in: Klinefelter Syndrome gonadotropin [go´nah-do-tro″pin] any hormone having a stimulating effect on the gonads. Two such hormones are secreted by the ...

• Gonadotrophin | Define Gonadotrophin at Dictionary.com

Gonadotrophin definition, a gonadotropic substance. See more. Thesaurus Translate Puzzles & Games Reference Word of the Day Blog Slideshows Apps by Dictionary My Account Log Out Log In follow Dictionary.com Dictionary ...

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★リンクテーブル★

リンク元	「GTH」
拡張検索	「serum gonadotrophin」「chorionic gonadotrophin」「human chorionic gonadotrophin」「human menopausal gonadotrophin」

「GTH」

　　[★]

• 性腺刺激ホルモン

関

gonadotrophin、gonadotropic hormone、gonadotropin

「serum gonadotrophin」

　　[★]

血清ゴナドトロピン、血清性ゴナドトロピン、血清性性腺刺激ホルモン、血清性腺刺激ホルモン

関

serum gonadotropin

「chorionic gonadotrophin」

　　[★] 絨毛性ゴナドトロピン、胎盤性性腺刺激ホルモン

関

choriogonadotropin、chorionic gonadotropin

「human chorionic gonadotrophin」

　　[★] ヒト絨毛性ゴナドトロピン

「human menopausal gonadotrophin」

　　[★] ヒト閉経期ゴナドトロピン