gastrointestinal hormone gastrointestinal hormone 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 glands but are spread throughout the digestive tract. they exert their autocrine and paracrine actions that integrate gastrointestinal function. types the gastrointestinal hormones can be divided into three main groups based upon their chemical structure. gastrin–cholecystokinin family: gastrin and cholecystokinin secretin family: secretin, glucagon, vasoactive intestinal peptide and gastric inhibitory peptide somatostatin family motilin family substance p. 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: 1719 hormone or peptidemolecular weight (da)number of amino acidsmain gut localizationprincipal physiologic actions gastrin family cholecystokinin391833 (also 385, 59)duodenum and jejunum, enteric nervesstimulates 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 gastrin209817both forms of gastrin are found in the gastric antrum and duodenumgastrins stimulate the secretion of gastric acid, pepsinogen, intrinsic factor, and secretin; stimulate intestinal mucosal growth; increase gastric and intestinal motility big gastrin383934 secretin-glucagon family secretin305627duodenum and jejunumstimulates pancreatic secretion of hco3, enzymes and insulin; reduces gastric and duodenal motility, inhibits gastrin release and gastric acid secretion vasoactive intestinal polypeptide (vip)332628enteric nervesrelaxes 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 glucose-dependent insulinotropic497642duodenum and jejunumstimulates insulin release; reduces gastric and intestinal motility; increases fluid and electrolyte secretion from small intestine brief description of some gi regulatory peptides: 1720 hormone or peptidemajor tissue locations in the gutprincipal known actions bombesinthroughout the gut and pancreasstimulates release of cholecystokinin (cck) and gastrin calcitonin gene-related peptideenteric nervesunclear chromogranin aneuroendocrine cellssecretory protein enkephalinsstomach, duodenumopiate-like actions enteroglucagonsmall intestine, pancreasinhibits insulin secretion galaninenteric nerves ghrelinstomachstimulates appetite, increases gastric emptying glucagon-like peptide 1pancreas, ileumincreases insulin secretion glucagon-like peptide 2ileum, colonenterocyte-specific growth hormone growth factorsthroughout the gutcell proliferation and differentiation growth hormone-releasing factorsmall intestineunclear leptinstomachappetite control motilinthroughout the gutincreases gastric emptying and small bowel motility neuropeptide yenteric nervesregulation of intestinal blood flow neurotensinileumaffects gut motility; increases jejunal and ileal fluid secretion pancreatic polypeptidepancreasinhibits pancreatic and biliary secretion peptide yycoloninhibits food intake somatostatinstomach, pancreasinhibits secretion and action of many hormones substance penteric nervesunclear trefoil peptidesstomach, intestinemucosal protection and repair