Adrenocorticotropic hormone
57997
224850474
2008-07-10T18:20:25Z
128.220.159.20
{{Unreferenced|date=December 2007}}
{{protein
| Name = proopiomelanocortin (adrenocorticotropin/ beta-lipotropin/ alpha-melanocyte stimulating hormone/ beta-melanocyte stimulating hormone/ beta-endorphin)
| caption =
| image =
| width =
| HGNCid = 9201
| Symbol = POMC
| AltSymbols =
| EntrezGene = 5443
| OMIM = 176830
| RefSeq = NM_000939
| UniProt = P01189
| PDB =
| ECnumber =
| Chromosome = 2
| Arm = p
| Band = 23
| LocusSupplementaryData =
}}
'''Adrenocorticotropic hormone''' ({{PronEng|əˈdriːnoʊˌkɔrtɪkoʊˈtrɒpɪk ˈhɔrmoʊn/, /-ˈtroʊpɪk}}) ('''ACTH''' or '''corticotropin''') is a [[polypeptide]] [[hormone]] produced and secreted by the [[pituitary gland]]. It is an important component of the [[hypothalamic-pituitary-adrenal axis]].
==Production==
ACTH is synthesised from [[pro-opiomelanocortin]] (POMC) and secreted from [[corticotrope]]s in the [[anterior pituitary|anterior lobe]] (or [[adenohypophysis]]) of the [[pituitary gland]] in response to the hormone [[corticotropin-releasing hormone]] (CRH) released by the [[hypothalamus]]. It is also produced by cells of immune system ([[T cell]]s, [[B cell]]s and [[macrophage]]s) as a response to stimuli that go along with stress (including CRH).
POMC is cleaved into ACTH and β-lipotropin. γ-[[lipotropin]] and [[β-endorphin]] result from the cleavage of this β-lipotropin.
==Structure==
ACTH consists of 39 [[amino acid]]s, the first 13 of which (counting from the N-terminus) may be cleaved to form [[α-melanocyte-stimulating hormone]] (α-MSH). (This common structure is one reason that patients with [[hypocortisolism]] or [[Addison's disease]], in which ACTH levels are elevated, often present with [[hyperpigmentation|excessively tanned skin]].)
After a short period of time, ACTH is cleaved into α-[[melanocyte-stimulating hormone]] (α-MSH) and CLIP, a peptide with unknown activity in humans.
==Function==
ACTH acts through the stimulation of cell surface [[ACTH receptor]]s, which are primarily located on the [[Adrenal cortex|adrenocortical cells]].
ACTH stimulates the cortex of the [[adrenal gland]] and boosts the synthesis of [[corticosteroid]]s, mainly [[glucocorticoid]]s but also sex steroids ([[androgen]]s).
ACTH is also related to the [[circadian rhythm]] in many organisms.
The [[half-life]] of ACTH in human blood is about ten minutes.
==Synthetic ACTH==
An active synthetic form of ACTH, consisting of the first 23 amino acids of native ACTH, was first synthesized by Klaus Hofmann at the [[University of Pittsburgh]].<ref>{{cite web |title=Simulated ACTH |journal=[[Time (magazine)|Time]]|year=1960 |issue=December 12 |url=http://www.time.com/time/magazine/article/0,9171,871916,00.html}}</ref>
ACTH is available as a synthetic derivative in the forms of [[cosyntropin]], tradename Cortrosyn and synacthen (synthetic ACTH). Both are very rarely used in place of [[glucocorticoids]] to treat secondary [[adrenal insufficiency]] in a hospital setting, but are primarily used to conduct the [[ACTH stimulation test]].
ACTH was first synthesized as a replacement for Acthar Gel, a long-lasting animal product. Once relatively inexpensive, it is currently an extremely expensive pharmaceutical product. Prices per vial have been as high as $25,000.
==Associated conditions==
* [[Addison's disease]]
* [[Small cell carcinoma]] (a common cause of ACTH secreted ectopically)
* [[Adrenoleukodystrophy]]
* [[Congenital adrenal hyperplasia]]
* [[Cushing's syndrome]]
* [[Nelson's syndrome]]
==References==
{{Reflist}}
== See also ==
* [[Hypothalamic-pituitary-adrenal axis|Pituitary-adrenal axis]]
* [[ACTH stimulation test]]
{{Hormones}}
{{Neuropeptides}}
[[Category:Anterior pituitary hormones]]
[[Category:HPA axis]]
[[Category:Peptide hormones]]
[[bg:Адренокортикотропен хормон]]
[[cs:Adrenokortikotropní hormon]]
[[da:Adrenokortikotropt hormon]]
[[de:Adrenocorticotropin]]
[[es:Hormona adrenocorticotropa]]
[[fr:Hormone corticotrope]]
[[id:Hormon Adrenocorticotropic]]
[[it:Ormone adrenocorticotropo]]
[[he:הורמון אדרנוקורטיקוטרופי]]
[[lt:AKTH]]
[[mk:Адренокортикотропин]]
[[nl:Corticotropine]]
[[ja:副腎皮質刺激ホルモン]]
[[no:Adrenokortikotropt hormon]]
[[pl:Hormon adrenokortykotropowy]]
[[pt:Hormônio adrenocorticotrófico]]
[[ru:Адренокортикотропный гормон]]
[[sk:Kortikotropín]]
[[fi:Kortikotropiini]]
[[sv:Adrenokortikotropiskt hormon]]
[[zh:促腎上腺皮質素]]