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[[Ficheiro:Activin inhibin.png|thumb|330px|Diagrama esquemático das estruturas das inhibinas e das hormonas relacionadas activinas. A liña negra entre os monómeros representa unha [[ponte disulfuro]].]]
== FunctionFuncións ==
Tanto en machos coma en femias a inhibina inhibe a produción de [[hormona estimulante dos folículos]] (FSH) da [[hipoófise]] e da [[hormona liberadora da gonadotropina]] (GnRH) do [[hipotálamo]]. Porén, o mecanismo difire entre os xéneros:
▲=== ActivinNas femias ===
Activin is produced in the [[gonad]]s, [[pituitary gland]], [[placenta]], and other organs:
A inhibina prodúcese nos [[ovario]]s, [[hipófise]] (ou pituitaria), e [[placenta]] e outros órganos.
Nas mulleres, a [[FSH]] estimula a secreción ovárica de inhibina nas [[célula da granulosacélulas da granulosa]] dos folículos ováricos. Á súa vez a inhibina suprime a produción de FSH.
* In the [[ovarian follicle]], activin increases FSH binding and FSH-induced [[Aromaticity|aromatization]]. It participates in [[androgen]] synthesis enhancing [[Luteinizing hormone|LH]] action in the [[ovary]] and [[Testicle|testis]]. In the male, activin enhances [[spermatogenesis]].
* A secreción de ''inhibina B'' ten un pico ao inicio e ata mediada a fase folicular do ciclo ovárico, e un segundo pico na [[ovulación]].
* Activin is strongly expressed in wounded [[skin]], and overexpression of activin in [[Epidermis (skin)|epidermis]] of [[Genetically modified organism|transgenic]] [[Mouse|mice]] improves wound healing and enhances [[scar]] formation. Its action in wound repair and skin [[morphogenesis]] is through stimulation of [[keratinocyte]]s and [[stromal cell]]s in a dose-dependent manner.<ref name="pmid16127153">{{cite journal | author = Bamberger C, Schärer A, Antsiferova M, Tychsen B, Pankow S, Müller M, Rülicke T, Paus R, Werner S | title = Activin Controls Skin Morphogenesis and Wound Repair Predominantly via Stromal Cells and in a Concentration-Dependent Manner via Keratinocytes | journal = Am. J. Pathol. | volume = 167 | issue = 3 | pages = 733–47 | year = 2005 | month = September | pmid = 16127153 | pmc = 1698729 | doi = 10.1016/S0002-9440(10)62047-0| url = http://ajp.amjpathol.org/cgi/pmidlookup?view=long&pmid=16127153 }}</ref>
* A secreción de''inhibina A'' atingue o seu pico mediada a fase lútea.
* Activin also regulates the [[morphogenesis]] of branching organs such as the [[prostate]], [[lung]], and especially [[kidney]]. Activin A increased the expression level of [[type-I collagen]] suggesting that activin A acts as a potent activator of [[fibroblast]]s.
A secreción de inhibin diminúe por efecto da [[hormona liberadora de gonadotropina]] (GnRH), e é potenciada polo [[factor de crecemento 1 similar á insulina]] (IGF-1).
* Lack of activin during development results in neural developmental defects.
=== InhibinNos machos ===
ItSecrétana isas secreted[[célula fromde theSertoli|células de Sertoli]] dos [[ Sertolitúbulo cellseminífero|túbulos seminíferos]] dos [[testículo]]s , <ref>{{cite journal |author=Skinner M, McLachlan R, Bremner W |title=Stimulation of Sertoli cell inhibin secretion by the testicular paracrine factor PModS |journal=Mol Cell Endocrinol |volume=66 |issue=2 |pages=239–49 |year=1989 |pmid=2515083 |doi=10.1016/0303-7207(89)90036-1}}</ref> . located in theOs [[ seminiferous tubulesandróxeno]] s insideestimulan thea [[testes]].produción [[Androgens]]de stimulate inhibin productioninhibina; thisesta [[ proteinproteína]] maypode tamén alsocontribuír helpa toregular locallylocalmente regulatea [[ spermatogenesisespermatoxénese]]. ▼
In both females and males, inhibin inhibits [[follicle-stimulating hormone|FSH]] production and [[Gonadotropin-releasing hormone|GnRH]] release from the hypothalamus. However, the overall mechanism differs between the genders:
==== In females ====
Inhibin is produced in the [[gonads]], [[pituitary gland]], [[placenta]] and other organs.
In women, FSH stimulates the secretion of inhibin from the [[granulosa cell]]s of the ovarian follicles in the [[ovary|ovaries]]. In turn, inhibin suppresses FSH.
* ''Inhibin B'' reaches a peak in the early- to mid-[[menstrual cycle|follicular phase]], and a second peak at [[ovulation]].
* ''Inhibin A'' reaches its peak in the mid-[[menstrual cycle|luteal phase]].
Inhibin secretion is diminished by [[Gonadotropin-releasing hormone|GnRH]], and enhanced by [[insulin-like growth factor]]-1 (IGF-1).
==== In males ====
▲It is secreted from the [[Sertoli cell]]s,<ref>{{cite journal |author=Skinner M, McLachlan R, Bremner W |title=Stimulation of Sertoli cell inhibin secretion by the testicular paracrine factor PModS |journal=Mol Cell Endocrinol |volume=66 |issue=2 |pages=239–49 |year=1989 |pmid=2515083 |doi=10.1016/0303-7207(89)90036-1}}</ref> located in the [[seminiferous tubules]] inside the [[testes]]. [[Androgens]] stimulate inhibin production; this [[protein]] may also help to locally regulate [[spermatogenesis]].
== Mechanism of action ==
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