Editing Growth hormone (section)

===Function===
[[File:Endocrine growth regulation.svg|thumb|240px|Main pathways in endocrine regulation of growth]]

Effects of growth hormone on the tissues of the body can generally be described as [[anabolism|anabolic]] (building up).  Like most other peptide hormones, GH acts by interacting with a specific [[receptor (biochemistry)|receptor]] on the surface of cells.{{cn|date=November 2024}}

Increased height during childhood is the most widely known effect of GH.  Height appears to be stimulated by at least two mechanisms:

# Because [[polypeptide]] hormones are not fat-[[soluble]], they cannot penetrate [[cell membranes]]. Thus, GH exerts some of its effects by binding to receptors on target cells, where it activates the [[MAPK/ERK pathway]].<ref name="Binder_2007">{{cite book |vauthors=Binder G, Wittekindt N, Ranke MB | journal = Hormone Research in Paediatrics | title = Noonan Syndrome: Genetics and Responsiveness to Growth Hormone Therapy |date=February 2007 | volume = 67 | isbn = 978-3-8055-8255-1 | issue = Supplement 1 | pages = 45–49 | doi=10.1159/000097552 | doi-broken-date = 1 November 2024 | s2cid = 84531041 | url = https://books.google.com/books?id=nQ9ilbixQEgC&q=gh%20growth%20hormone%20ras&pg=PA46}}</ref> Through this mechanism GH directly stimulates division and multiplication of [[chondrocyte]]s of [[cartilage]].
# GH also stimulates, through the [[JAK-STAT signaling pathway]],<ref name="Binder_2007"/> the production of [[insulin-like growth factor 1]] (IGF-1, formerly known as somatomedin C), a hormone homologous to [[proinsulin]].<ref>{{cite web | url = http://www.lib.mcg.edu/edu/eshuphysio/program/section5/5ch2/s5ch2_19.htm | title = Actions of Anterior Pituitary Hormones: Physiologic Actions of GH | publisher = Medical College of Georgia | year = 2007 | access-date = 2008-01-16 | url-status = dead | archive-url = https://web.archive.org/web/20080111163402/http://www.lib.mcg.edu/edu/eshuphysio/program/section5/5ch2/s5ch2_19.htm | archive-date = 2008-01-11 }}</ref> The [[liver]] is a major target organ of GH for this process and is the principal site of IGF-1 production. IGF-1 has growth-stimulating effects on a wide variety of tissues. Additional IGF-1 is generated within target tissues, making it what appears to be both an [[endocrine gland|endocrine]] and an [[autocrine]]/[[paracrine]] hormone. IGF-1 also has stimulatory effects on [[osteoblast]] and [[chondrocyte]] activity to promote bone growth.

In addition to increasing height in children and adolescents, growth hormone has many other effects on the body:
* Increases [[calcium]] retention,<ref>{{cite journal | vauthors = Ahmad A, Thomas J, Clewes A, Hokins MT, Guzder R, Ibrahim H, Durham B, Vora JP, Fraser WD | title = Effects of Growth Hormone Replacement on Parathyroid Hormone Sensitivity and Bone Mineral Metabolism | journal = The Journal of Clinical Endocrinology & Metabolism | date=2003-06-01 | volume = 88 | issue = 6 | pages = 2860–2868 | doi=10.1210/jc.2002-021787 | pmid = 12788900| doi-access = free }}</ref> {{Citation needed|date=October 2015}} and strengthens and increases the [[mineralization of bone]]
* Increases [[muscle]] mass through [[sarcomere]] [[hypertrophy]]
* Promotes [[lipolysis]]
* Increases [[protein synthesis]]
* Stimulates the growth of all internal organs excluding the [[brain]]
* Plays a role in [[homeostasis]]
* Reduces [[liver]] uptake of [[glucose]]
* Promotes [[gluconeogenesis]] in the liver<ref>{{cite web | vauthors = King MW | url = http://web.indstate.edu/thcme/mwking/peptide-hormones.html#gh | title = Structure and Function of Hormones: Growth Hormone | publisher = [[Indiana State University]] | year = 2006 | access-date = 2008-01-16 | archive-date = 2007-12-06 | archive-url = https://web.archive.org/web/20071206035951/http://web.indstate.edu/thcme/mwking/peptide-hormones.html#gh | url-status = dead }}</ref>
* Contributes to the maintenance and function of [[pancreatic islets]]
* Stimulates the [[immune system]]
* Increases deiodination of T4 to T3<ref>T.F. Davies (ed.), A Case-Based Guide to Clinical Endocrinology, 2008, pag.16</ref>
* Induces insulin resistance<ref>{{Cite journal |last1=Sharma |first1=Rita |last2=Kopchick |first2=John J. |last3=Puri |first3=Vishwajeet |last4=Sharma |first4=Vishva M. |date=2020-12-01 |title=Effect of Growth Hormone on Insulin Signaling |journal=Molecular and Cellular Endocrinology |volume=518 |pages=111038 |doi=10.1016/j.mce.2020.111038 |issn=0303-7207 |pmc=7606590 |pmid=32966863}}</ref>