Gastrointestinal hormones in disease

At least 30 peptides have been isolated from the gastroenteropancreatic axis, so named because these peptides regulate secretion within the alimentary canal, motor activities of the gut, and secretions of the exocrine and endocrine pancreas. Because gastrointestinal function is protected from failure by a variety of regulatory systems, deficiency states of these peptides usually are associated only with subtle dysfunction. An excess of gastrointestinal peptide, in contrast, can cause severe disease. The four peptides that provide the focus for this discussion are cholecystokinin, gastric inhibitory polypeptide, pancreatic polypeptide, and vasoactive intestinal polypeptide.