Gastrointestinal hormone explained

The gastrointestinal hormones (or gut hormones) constitute a group of hormones secreted by enteroendocrine cells in the stomach, pancreas, and small intestine that control various functions of the digestive organs. Later studies showed that most of the gut peptides, such as secretin, cholecystokinin or substance P, were found to play a role of neurotransmitters and neuromodulators in the central and peripheral nervous systems.[1]

Enteroendocrine cells do not form glands but are spread throughout the digestive tract. They exert their autocrine and paracrine actions that integrate gastrointestinal function.[2]

Types

The gastrointestinal hormones[3] can be divided into three main groups based upon their chemical structure.

Ghrelin is a peptide hormone released from the stomach and liver and is often referred to as the "hunger hormone" since high levels of it are found in individuals that are fasting. Ghrelin agonistic treatments can be used to treat illnesses such as anorexia and loss of appetites in cancer patients. Ghrelin treatments for obesity are still under intense scrutiny and no conclusive evidence has been reached. This hormone stimulates growth hormone release.Amylin controls glucose homeostasis and gastric motility

Glucose-dependent insulinotropic polypeptide possesses an acute influence on food intake through its effects on adipocytes

Oxyntomodulin plays a role in controlling acid secretion and satiation

Characteristics of prominent forms of principal gut regulatory peptides[4]
Hormone or peptide Molecular weight (Da) Number of amino acidsMain gut localization Principal physiologic actions
Gastrin family
3918 33 (also 385, 59) Duodenum and jejunum, Enteric nerves Stimulates gallbladder contraction and intestinal motility; stimulates secretion of pancreatic enzymes, insulin, glucagon, and pancreatic polypeptides; has a role in indicating satiety; the C-terminal 8 amino acid peptide cholecystokinin (CCK)-8 retains full activity
2098 17 Both forms of gastrin are found in the gastric antrum and duodenum Gastrins stimulate the secretion of gastric acid, pepsinogen, intrinsic factor, and secretin; stimulate intestinal mucosal growth; increase gastric and intestinal motility
3839 34
Secretin-glucagon family
3056 27 Duodenum and jejunum Stimulates pancreatic secretion of HCO3, enzymes and insulin; reduces gastric and duodenal motility, inhibits gastrin release and gastric acid secretion
Vasoactive intestinal polypeptide (VIP) 3326 28 Enteric nerves Relaxes smooth muscle of gut, blood vessels, and genitourinary system; increases water and electrolyte secretion from pancreas and gut; releases hormones from pancreas, gut, and hypothalamus
4976 42 Duodenum and jejunum Stimulates insulin release; reduces gastric and intestinal motility; increases fluid and electrolyte secretion from small intestine
Brief Description of Some GI Regulatory Peptides
Hormone or peptide Major tissue locations in the gut Principal known actions
Throughout the gut and pancreas Stimulates release of cholecystokinin (CCK) and gastrin
Enteric nerves Unclear
Neuroendocrine cells Secretory protein
Stomach, duodenum Opiate-like actions
Small intestine, pancreas Inhibits insulin secretion
Enteric nerves
Stomach Stimulates appetite, increases gastric emptying
Pancreas, ileum Increases insulin secretion
Ileum, colon Enterocyte-specific growth hormone
Throughout the gut Cell proliferation and differentiation
Small intestine Unclear
Stomach Appetite control
Throughout the gut Increases gastric emptying and small bowel motility
Enteric nerves Regulation of intestinal blood flow
Ileum Affects gut motility; increases jejunal and ileal fluid secretion
Pancreas Inhibits pancreatic and biliary secretion
Colon Inhibits food intake
Stomach, pancreas Inhibits secretion and action of many hormones
Enteric nerves Unclear
Stomach, intestine Mucosal protection and repair

See also

External links

Notes and References

  1. Al-hussaniy . Hany A. . AL-Biati . Haedar A . 2022 . The Role of Leptin Hormone, Neuropeptide Y, Ghrelin and Leptin/Ghrelin ratio in Obesogenesis . Medical and Pharmaceutical Journal . 1 . 2 . 12–23 . 10.55940/medphar20227 . 2957-6067. free .
  2. Web site: Enteric Endocrine System. www.vivo.colostate.edu. 2016-09-16.
  3. Vella A and Drucker DJ (2011)Chapter 39 Gastrointestinal Hormones and Gut Endocrine Tumors, pp 1697-1707. In Williams Textbook of Endocrinology (2011, 12th edition)
  4. Book: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 5th edition. Elsevier Saunders. 978-1-4160-6164-9. Burtis CA, Ashwood ER, Bruns DE. 2012-10-14.