Editing Adrenocorticotropic hormone (section)

== Production and regulation ==
[[POMC]], ACTH and β-lipotropin are secreted from [[corticotropic cell]]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]].<ref>{{cite web|title=Adrenocorticotropic Hormone (ACTH)|url=http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/hypopit/acth.html|website=vivo.colostate.edu|url-status=dead|access-date=October 15, 2008|archive-date=May 22, 2023|archive-url=https://web.archive.org/web/20230522170645/http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/hypopit/acth.html}}</ref> The pre-pro-opiomelanocortin ([[Pre-proopiomelanocortin|Pre-POMC]]) is the precursor of POMC, its cleavage forms POMC.<ref>{{Cite journal |last=Chen |first=Xuanyu |date=11 February 2024 |title=An analysis of POMC gene methylation and expression in patients with schizophrenia |journal=International Journal of Developmental Neuroscience |volume=84 |issue=3 |publisher=Wiley |pages=208–216 |doi=10.1002/jdn.10319 |pmid=38343101 |doi-access=free}}</ref> ACTH, on the other hand, is produced from the cleavage of POMC. The removal of the signal [[peptide]] during [[Translation (biology)|translation]] produces the 241-amino acid [[polypeptide]] POMC, which undergoes a series of [[post-translational modifications]] such as [[phosphorylation]] and [[glycosylation]] before it is proteolytically cleaved by [[endopeptidases]] to yield various polypeptide fragments with varying physiological activity. These fragments include:<ref>{{cite web|title=Pro-opiomelocortin precursor|url=https://www.uniprot.org/uniprot/P01189|access-date=April 8, 2013|website=UniProt|archive-date=July 16, 2024|archive-url=https://web.archive.org/web/20240716004206/https://www.uniprot.org/uniprot/P01189|url-status=live}}</ref>
{| class="wikitable"
|-
! polypeptide fragment !! alias !! abbreviation !! amino acid [[residue (chemistry)|residues]]
|-
| NPP ||
|NPP
| 27–102
|-
| melanotropin gamma || || γ-MSH || 77–87
|-
| potential peptide  || || || 105–134
|-
| corticotropin || adrenocorticotropic hormone || ACTH || 138–176
|-
| melanotropin alpha ||  melanocyte-stimulating hormone ||  α-MSH || 138–150
|-
| corticotropin-like intermediate peptide || ||  CLIP || 156–176
|-
| lipotropin beta || || β-LPH || 179–267
|-
| lipotropin gamma || ||  γ-LPH || 179–234
|-
| melanotropin beta || || β-MSH || 217–234
|-
| beta-endorphin || || || 237–267
|-
| met-enkephalin || || || 237–241
|}

In order to regulate the secretion of ACTH, many substances secreted within this axis exhibit slow/intermediate and fast feedback-loop activity. [[Glucocorticoids]] secreted from the adrenal cortex work to inhibit CRH secretion by the hypothalamus, which in turn decreases anterior pituitary secretion of ACTH. Glucocorticoids may also inhibit the rates of POMC gene [[Transcription (genetics)|transcription]] and peptide synthesis. The latter is an example of a slow feedback loop, which works on the order of hours to days, whereas the former works on the order of minutes.

The [[half-life]] of ACTH in human blood is reported to be between ten and 30 minutes.<ref name="pmid14230021">{{cite journal | vauthors = Yalow RS, Glick SM, Roth J, Berson SA | title = Radioimmunoassay of human plasma ACTH | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 24 | issue = 11 | pages = 1219–25 | date = November 1964 | pmid = 14230021 | doi = 10.1210/jcem-24-11-1219 }}</ref><ref>{{cite book | vauthors = Patel K | title = Stability and Characterization of Protein and Peptide Drugs | chapter = Stability of Adrenocorticotropic Hormone (ACTH) and Pathways of Deamidation of Asparaginyl Residue in Hexapeptide Segments | series = Pharmaceutical Biotechnology | volume = 5 | pages = 201–20 | date = 1993 | pmid = 8019694 | doi = 10.1007/978-1-4899-1236-7_6 | isbn = 978-1-4899-1238-1 }}</ref><ref>{{cite journal | vauthors = Veldhuis JD, Iranmanesh A, Naftolowitz D, Tatham N, Cassidy F, Carroll BJ | title = Corticotropin secretory dynamics in humans under low glucocorticoid feedback | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 86 | issue = 11 | pages = 5554–63 | date = November 2001 | pmid = 11701735 | doi = 10.1210/jcem.86.11.8046 | doi-access = free }}</ref>