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]]