Follicle-Stimulating Hormone

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Related to follitropin: follitropin alpha, follitropin beta

gonadotropic hormone

gonadotropic hormone (gōˌnădətrŏpˈĭk) or gonadotropin, any one of three glycoprotein (see protein) hormones released by either the anterior pituitary gland or the placenta (the organ in which maternal and fetal blood exchange nutrients and waste products) that have various effects upon the ovaries and testes (see testis). Gonadotropin-releasing hormone (Gn-RH) is produced and released from the hypothalamus. Gn-RH release stimulates the secretion of both follicle-stimulating hormone (FSH) and lutenizing hormone (LH) from the pituitary gland. Gn-RH is a peptide composed of ten amino acids which are synthesized in the hypothalamus (that portion of the brain nearest the pituitary). This hormone travels in the bloodstream to the anterior pituitary, where it causes the release of the gonadotropic hormones. The hormones FSH and LH inhibit the amount of Gn-RH released by a mechanism called “negative feedback.” In the female, FSH causes an increase in the weight of the ovaries and encourages the growth of Graafian follicles (containing maturing eggs); in males, FSH produces spermatogenesis in the testes. In females, secretion of LH is associated with the maturation of the follicles, the manifestation of heat (or estrus), and the release of the egg from the follicle, which is transformed into a corpus luteum. In males, LH stimulates the testes to release testosterone. Sex hormones released from the ovaries and testes eventually reach the hypothalamus and help to regulate the hormonal cycle. Human chorionic gonadotropin (HCG), produced in the placenta, helps to maintain pregnancy once a fetus begins to develop. It appears in the urine in approximately the first week after the first missed menstrual period, and is the basis for two kinds of pregnancy tests; in the Ascheim-Zondek testm it causes the ovaries of an immature female rat or mouse to gain weight and produce ripened follicles, and in the Friedman test, it stimulates female rabbits to ovulate.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Follicle-Stimulating Hormone

 

(FSH), a gonado-trophic hormone in man and other vertebrates produced by the anterior pituitary.

Chemically, the hormone is a glycoprotein; its primary structure has not been established. The molecular weight of FSH in sheep is 67,000; the molecular weight for swine is 29,000. The molecule consists of two subunits, alpha and beta. The alpha sub-unit is similar to the alpha subunits of luteinizing and thyrotropic hormones, whereas the beta subunit differs from the beta subunits of these hormones. The biological properties of FSH are determined solely by the beta subunit (in lizards, the beta subunit is as active as the native hormone). In females, FSH stimulates the development of follicles up to ovulation and promotes the growth of ovarian interstitial tissue; these effects lead to an increase in the secretion of female sex hormones, or estrogens. In males, FSH promotes the growth of the seminiferous tubules and stimulates spermatogenesis and the secretion of male sex hormones, or androgens. FSH acts jointly with the luteinizing hormone.

The synthesis and excretion of FSH are regulated both by the FSH releasing factor, which is elaborated by the hypothalamus, and by the levels of androgen and estrogen in the blood; as the concentrations of androgen and estrogen increase, the secretion of FSH decreases.

REFERENCES

Pankov, Iu. A. “Struktura i svoistva gipofizarnykh gormonov,” part 2: “Belkovye gormony gipofiza.” Problemy endokrinologii, 1974, vol. 20, no. 3.
Pierce, J G. “Properties of Pituitary Thyroid-stimulating Hormone in Comparison With Those of the Gonadotropins.” Biochemical Society Transactions, 1974, vol. 2, no. 5.

V. M. SAMSONOVA

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

follicle-stimulating hormone

[¦fäl·ə·kəl ¦stim·yə‚lād·iŋ ′hȯr‚mōn]
(biochemistry)
A protein hormone released by the anterior pituitary of vertebrates which stimulates growth and secretion of the Graafian follicle and also promotes spermatogenesis. Abbreviated FSH.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
In China, Recombinant Follitropin Beta is used to treat anovulation (including polycystic ovary disease, PCOD) that cannot be cured by clomiphene citrate.
The Follistim AQ Cartridge is designed to be used only with the Follistim Pen (TM), an innovative pen device that facilitates accurate delivery of individualized doses of pre-mixed follitropin beta injection, a highly effective and widely used prescription fertility medication made from state of the art recombinant DNA technology.
The data shows that individualised treatment with REKOVELLE, as compared to treatment with conventional rFSH (follitropin alfa), had similar results for the co-primary endpoints of ongoing pregnancy rates and ongoing implantation rates.
Ferring Pharmaceuticals, a multinational pharmaceutical company, has received recommended approval from the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) for its Rekovelle (follitropin delta) for controlled ovarian stimulation in women undergoing assisted reproductive technologies, it was reported yesterday.
Molecular, structural, and cellular biology of follitropin and follitropin receptor.
HCG[alpha] is essentially identical to that of lutropin (LH), follitropin (FSH), and thyrotropin (TSH), whereas hCG[beta] is unique to hCG and confers its biological and immunological specificity (1).
Ovarian stimulation was conducted with recombinant follicle-stimulating hormone (follitropin beta, Puregon; Organon), starting at a daily dose of 50-100 IU on the third day of the cycle.