A peptide hormone secreted by the follicular cells of the ovary and the Sertoli cells of the testis that inhibits secretion of follicle stimulating hormone from the anterior pituitary.
|
Results for inhibin
|
On this page:
|
Medical Dictionary:
in·hib·in
(ĭn-hĭb'ĭn)n.
A peptide that acts to inhibit follicle-stimulating hormonal secretion from the pituitary gland.
Veterinary Dictionary:
inhibin
A nonsteroid hormone originating in the seminiferous tubules and ovarian follicles and which regulates follicle-stimulating hormone secretion.
Wikipedia:
inhibin
|
inhibin, alpha
|
|
| Identifiers | |
| Symbol | INHA |
| Entrez | 3623 |
| HUGO | 6065 |
| OMIM | 147380 |
| RefSeq | NM_002191 |
| UniProt | P05111 |
| Other data | |
| Locus | Chr. 2 q33-qter |
|
inhibin, beta A (activin A, activin AB alpha polypeptide)
|
|
| Identifiers | |
| Symbol | INHBA |
| Entrez | 3624 |
| HUGO | 6066 |
| OMIM | 147290 |
| RefSeq | NM_002192 |
| UniProt | P08476 |
| Other data | |
| Locus | Chr. 7 p15-p13 |
|
inhibin, beta B (activin AB beta polypeptide)
|
|
| Identifiers | |
| Symbol | INHBB |
| Entrez | 3625 |
| HUGO | 6067 |
| OMIM | 147390 |
| RefSeq | NM_002193 |
| UniProt | P09529 |
| Other data | |
| Locus | Chr. 2 cen-q13 |
Inhibin is a peptide that is an inhibitor of FSH synthesis and secretion,[1] and participates in the regulation of the menstrual cycle.
Structure
Inhibin contains an alpha and beta subunit linked by disulfide bonds. Two forms of inhibin differ in their beta subunits (A or B), while their alpha subunits are identical.
Inhibin belongs to the transforming growth factor-β (TGF-β) superfamily.
Action
In women
In women, FSH stimulates the secretion of inhibin from the granulosa cells of the ovarian follicles in ovary. In turn, inhibin suppresses FSH.
Inhibin secretion is diminished by GnRH, and enhanced by insulin-like growth factor-1 (IGF-1).
- Inhibin B reaches a peak in the early- to mid-follicular phase, and a second peak at ovulation.
- Inhibin A reaches its peak in the mid-luteal phase.
Inhibin is produced in the gonads, pituitary gland, placenta and other organs.
In men
In men, it is a hormone that inhibits FSH production.
It is secreted from the Sertoli cells,[2] located in the seminiferous tubule inside the testes.
Activin
Activin is a related peptide that counteracts inhibin.
Clinical significance
Quantification of inhibin A is part of the prenatal quad screen that can be administered during pregnancy at a gestational age of 16-18 weeks. An elevated inhibin A (along with an increased beta-hCG, decreased AFP, and a decreased estriol) is [3] suggestive of the presence of a fetus with Down's syndrome. As a screening test, abnormal quad screen test results need to be followed up with more definitive tests.
It also has been used as a marker for ovarian cancer.[4][5]
References
- ^ van Zonneveld P, Scheffer G, Broekmans F, Blankenstein M, de Jong F, Looman C, Habbema J, te Velde E (2003). "Do cycle disturbances explain the age-related decline of female fertility? Cycle characteristics of women aged over 40 years compared with a reference population of young women". Hum Reprod 18 (3): 495-501. PMID 12615813.
- ^ Skinner M, McLachlan R, Bremner W (1989). "Stimulation of Sertoli cell inhibin secretion by the testicular paracrine factor PModS". Mol Cell Endocrinol 66 (2): 239-49. PMID 2515083.
- ^ Aitken D, Wallace E, Crossley J, Swanston I, van Pareren Y, van Maarle M, Groome N, Macri J, Connor J (1996). "Dimeric inhibin A as a marker for Down's syndrome in early pregnancy". N Engl J Med 334 (19): 1231-6. PMID 8606718.
- ^ Robertson D, Pruysers E, Jobling T. "Inhibin as a diagnostic marker for ovarian cancer". Cancer Lett. PMID 17320281.
- ^ Robertson D, Pruysers E, Burger H, Jobling T, McNeilage J, Healy D (2004). "Inhibins and ovarian cancer". Mol Cell Endocrinol 225 (1-2): 65-71. PMID 15451569.
| TGF beta signaling pathway | |
|---|---|
| TGF beta superfamily of ligands | TGF beta family
(TGF-β1, TGF-β2, TGF-β3) Bone morphogenetic proteins (BMP2, BMP3, BMP4, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP10 , BMP15) Growth differentiation factors (GDF1, GDF2, GDF3, GDF5, GDF6, GDF7, Myostatin/GDF8, GDF9, GDF10, GDF11, GDF15) Other (Activin A and B/Inhibin A and B, Anti-müllerian hormone, Nodal) |
| TGF beta receptors | TGFBR1: Activin type 1 receptors (ACVR1, ACVR1B, ACVR1C) - ACVRL1 - BMPR1 (BMPR1A - BMPR1B) TGFBR2: Activin type 2 receptors (ACVR2A, ACVR2B) - AMHR2 - BMPR2 TGFBR3: betaglycan |
| Transducers/SMAD | R-SMAD (SMAD1, SMAD2, SMAD3, SMAD5, SMAD9) - I-SMAD (SMAD6, SMAD7) - SMAD4 |
| Ligand Inhibitors | Cerberus - Chordin - DAN - Decorin - Follistatin - Gremlin - Lefty - LTBP1 - Noggin - THBS1 |
| Coreceptors | BAMBI - Cripto |
| Other | SARA |
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Join the WikiAnswers Q&A community. Post a question or answer questions about "inhibin" at WikiAnswers.
Copyrights:
 |
 | Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved. Read more |
 |
| Medical Dictionary. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Read more |
 |
| Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved. Read more |
 |
| Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Inhibin". Read more |
Search for answers directly from your browser with the FREE Answers.com Toolbar!
Click here to download now. 
Get Answers your way! Check out all our free tools and products.
ADVERTISEMENT
Tackle These
Keep Reading
ADVERTISEMENT
