Gastrointestinal hormone

From Wikipedia, the free encyclopedia
Jump to: navigation, search

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.

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

Types of Gastrointestinal hormones[edit]

The gastrointestinal hormones 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 antagonistic 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[1]
Hormone/Peptide Molecular Weight (Da) No. of Amino Acids Main Gut Localization Principal Physiologic Actions
Gastrin Family
Cholecystokinin 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
Little gastrin 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
Big gastrin 3839 34
Secretin-Glucagon Family
Secretin 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, and genitourinary system; increases water and electrolyte secretion from pancreas and gut; releases hormones from pancreas, gut, and hypothalamus
Glucose-dependent insulinotropic 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[2]
Hormone/Peptide Major Tissue Locations in Gut Principal Known Actions
Bombesin Throughout the gut and pancreas Stimulates release of cholecystokinin (CCK) and gastrin
Calcitonin gene-related peptide Enteric nerves Unclear
Chromogranin A Neuroendocrine cells Secretory protein
Enkephalins Stomach, duodenum Opiate-like actions
Enteroglucagon Small intestine, pancreas Inhibits insulin secretion
Galanin Enteric nerves
Ghrelin Stomach Stimulates appetite, increases gastric emptying
Glucagon-like peptide 1 Pancreas, ileum Increases insulin secretion
Glucagon-like peptide 2 Ileum, colon Enterocyte-specific growth hormone
Growth factors Throughout the gut Cell proliferation and differentiation
Growth hormone-releasing factor Small intestine Unclear
Leptin Stomach Appetite control
Motilin Throughout the gut Increases gastric emptying and small bowel motility
Neuropeptide Y Enteric nerves Regulation of intestinal blood flow
Neurotensin Ileum Affects gut motility; increases jejunal and ileal fluid secretion
Pancreatic polypeptide Pancreas Inhibits pancreatic and bilary secretion
Peptide YY Colon Inhibits food intake
Somatostatin Stomach, pancreas Inhibits secretion and action of many hormones
Substance P Enteric nerves Unclear
Trefoil peptides Stomach, intestine Mucosal protection and repair


See also[edit]

References[edit]

  1. ^ Burtis CA, Ashwood ER, Bruns DE. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 5th edition. Elsevier Saunders. p. 1719. ISBN 978-1-4160-6164-9. 
  2. ^ Burtis CA, Ashwood ER, Bruns DE. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 5th edition. Elsevier Saunders. p. 1720. ISBN 978-1-4160-6164-9. 

External links[edit]