Follicle-stimulating hormone
323328
225706721
2008-07-15T00:27:06Z
67.91.71.50
FSH not human specific
{{Unreferenced|date=December 2007}}
{{protein | Name = [[FSHB|Follicle-stimulating hormone, beta polypeptide]] | caption = Follicle-Stimulating Hormone | image = Follitropine.gif | width = 300 | HGNCid = 3964 | Symbol = [[FSHB]] | AltSymbols = | EntrezGene = 2487 | OMIM = 136530 | RefSeq = NM_000510 | UniProt = P01225 | PDB = | ECnumber = | Chromosome = 11 | Arm = p | Band = 13 | LocusSupplementaryData = }}
{{For|other uses of the term FSH|FSH (disambiguation)}}
'''Follicle-stimulating hormone''' ('''FSH''') is a [[hormone]] synthesized and secreted by [[gonadotrope]]s in the [[anterior pituitary gland]]. FSH and [[Luteinizing hormone|LH]] act synergistically in [[reproduction]]:
*In females, in the [[ovary]] FSH stimulates the growth of immature [[Graafian follicle]]s to maturation. Graafian follicles are the mature follicle. Primary follicles mature to Graafian follicles. As the follicle grows, it releases [[inhibin]], which shuts off the FSH production.
*In males, FSH enhances the production of [[androgen-binding protein]] by the [[Sertoli cell]]s of the [[testes]], and is critical for [[spermatogenesis]].
==Structure==
FSH is a [[glycoprotein]]. Each monomeric unit is a protein molecule with a sugar attached to it; two of these make the full, functional protein. Its structure is similar to those of [[Luteinizing hormone|LH]], [[Thyroid-stimulating hormone|TSH]], and [[Human chorionic gonadotropin|hCG]]. The protein dimer contains 2 [[polypeptide]] units, labeled alpha and beta subunits. The [[Alpha subunit of glycoprotein hormones|alpha subunits]] of LH, FSH, TSH, and hCG are identical, and contain 92 [[amino acids]]. The beta subunits vary. FSH has a beta subunit of 118 amino acids (FSHB), which confers its specific biologic action and is responsible for interaction with the [[FSH-receptor]]. The sugar part of the hormone is composed of [[fucose]], [[galactose]], [[mannose]], [[galactosamine]], [[glucosamine]], and [[sialic acid]], the latter being critical for its biologic [[half-life]]. The half-life of FSH is 3-4 hours.
Its molecular wt is 30000.
==Genes==
The gene for the [[Alpha subunit of glycoprotein hormones|alpha subunit]] is located on chromosome 6p21.1-23. It is expressed in different cell types. The gene for the FSH beta subunit is located on chromosome 11p13, and is expressed in gonadotropes of the pituitary cells, controlled by [[GnRH]], inhibited by [[inhibin]], and enhanced by [[activin]].
==Activity==
FSH regulates the development, growth, pubertal maturation, and reproductive processes of the human body.
* In both ''males'' and ''females'', FSH stimulates the maturation of [[germ cells]].
* In ''males'', FSH induces [[sertoli cells]] to secrete [[inhibin]] and stimulates the formation of sertoli-sertoli tight junctions ([[zonula occludens]]).
* In ''females'', FSH initiates follicular growth, specifically affecting granulosa cells. With the concomitant rise in inhibin B, FSH levels then decline in the late follicular phase. This seems to be critical in selecting only the most advanced follicle to proceed to ovulation. At the end of the luteal phase, there is a slight rise in FSH that seems to be of importance to start the next ovulatory cycle.
Like its partner, [[Luteinizing hormone|LH]], FSH release at the pituitary gland is controlled by pulses of [[gonadotropin-releasing hormone]] (GnRH). Those pulses, in turn, are subject to the oestrogen feed-back from the gonads.
==Disease states==
FSH levels are normally low during [[childhood]] and, in females, high after [[menopause]].
===High FSH levels===
High levels of Follicle-Stimulating Hormone are indicative of situations where the normal restricting feedback from the gonad is absent, leading to an unrestricted pituitary FSH production. Whereas this is normal in females leading up to and during postmenopause, it is abnormal during the reproductive years.
If the FSH level is high during the reproductive years, this may be a sign of:
# [[Premature menopause]] also known as Premature Ovarian Failure
# [[Gonadal dysgenesis]], [[Turner syndrome]]
# [[Castration]]
# [[Swyer syndrome]]
# Certain forms of [[CAH]]
# Testicular failure.
===Low FSH levels ===
Diminished secretion of FSH can result in failure of gonadal function (hypogonadism). This condition is typically manifest in males as failure in production of normal numbers of sperm. In females, cessation of reproductive cycles is commonly observed.
Conditions with very low FSH secretions are:
# [[Kallmann syndrome]]
# [[Hypothalamic suppression]]
# [[Hypopituitarism]]
# [[Hyperprolactinemia]]
# [[Gonadotropin deficiency]]
# Gonadal suppression therapy
##[[GnRH antagonist]]
##[[GnRH agonist]] ([[downregulation]]).
==Availability==
FSH is available mixed with LH in the form of [[Pergonal]] or Menopur, and other more purified forms of urinary [[gonadotropins]], as well as in a pure forms as recombinant FSH (Gonal F, Follistim). It is used commonly in infertility therapy to stimulate follicular development, notably in [[IVF]] therapy, as well as with interuterine insemination (IUI).
==External links==
*[http://infertilityblog.blogspot.com/2006/03/first-of-few-about-fsh-levels.html Day 3 FSH levels] From the Infertility Blog by Dr. Fred Licciardi
*[http://infertilityblog.blogspot.com/2006/03/high-fsh-excuse-to-send-patients-away.html High FSH: an excuse to send patients away] From the Infertility Blog by Dr. Fred Licciardi
* [http://infertilityblog.blogspot.com/2006/03/fsh-and-estradiolestrogen.html FSH and Estradiol]
* [http://www.thefertilesoul.com/Treatment/Imbalances/fsh.php Causes & Symptoms of High FSH]
* [http://www.highfshinfo.com Information on high FSH compiled by a woman with high FSH]
* [http://maybebaby.ctwfeatures.com Debating the imbalance as a cause of one couple's infertility]
{{Hormones}}
[[Category:Recombinant proteins]]
[[Category:Glycoproteins]]
[[Category:Peptide hormones]]
[[Category:Sex hormones]]
[[Category:In vitro fertilisation]]
[[Category:Gonadotropic hormones]]
[[cs:Folikuly stimulující hormon]]
[[da:Follikelstimulerende hormon]]
[[de:Follikelstimulierendes Hormon]]
[[dv:ފޮލިކަލް ސްޓިމިއުލޭޓިންގ ހޯރމޯން]]
[[es:Hormona foliculoestimulante]]
[[fr:Hormone folliculo-stimulante]]
[[hr:Folikulostimulirajući hormon]]
[[id:Follicle Stimulating Hormone]]
[[it:Ormone follicolo-stimolante]]
[[he:הורמון מגרה זקיק]]
[[lt:Folikulinas]]
[[mk:Фоликуло-стимулирачки хормон]]
[[nl:Follikelstimulerend hormoon]]
[[ja:卵胞刺激ホルモン]]
[[no:Follikkelstimulerende hormon]]
[[pl:Hormon folikulotropowy]]
[[pt:Hormônio folículo-estimulante]]
[[ru:Фолликулостимулирующий гормон]]
[[sk:Folikulostimulačný hormón]]
[[sv:Follikelstimulerande hormon]]
[[zh:卵泡刺激素]]