The table lists types of GEP endocrinocytes, producing by them hormones and mentioned their predominant localization in the organs of the middle part of the digestive tube.

Biological effects of hormones.

• Glucagon — increases the content of glucose and fatty acids in blood plasma: stimulates glycogenolysis in the liver and lipolysis in adipose tissue; inhibits the secretion of hydrochloric acid; It stimulates bile secretion, insulin and somatostatin secretion.
• Enkephalins #1, #2 — regulate blood microcirculation, peristalsis of the stomach and intestines; have an analgesic effect.
• Insulin — reduces the content of glucose and fatty acids in blood plasma: stimulates glucose uptake by cells and glycogenogenesis in the liver, enhances lipogenesis and blocks lipolysis in adipocytes.
• Somatostatin — suppresses the secretory activity of pancreatic and gastric cells, in particular — synthesis and release of pancreatic enzymes, insulin, glucagon, gastrin and hydrochloric acid.
• Vasoactive intestinal peptide — expands blood vessels, stimulates the release of bicarbonate-rich pancreatic juice, increases the secretion of insulin and pancreatic polypeptide, suppresses the secretion of hydrochloric acid.
• Serotonin #1, #2; stimulates the secretion of mucus and digestive enzymes, suppresses the secretion of hydrochloric acid, reduces the absorption of water and electrolytes in the intestine and regulates its peristalsis.
• Melatonin #1, #2 — universal regulator of biological rhythms, controls the processes of cell proliferation and differentiation, has an immunomodulatory effect.
• Substance P — regulates the motility of the organs of the gastrointestinal tract, dilates blood vessels, suppresses insulin secretion, participates in the modulation of pain sensitivity.
• Histamine — has a central role in the formation of hydrochloric acid.
• Gastrin — regulates the formation of hydrochloric acid by stimulating histamine secretion, participates in the regulation of gastric motility.
• Cholecystokinin-pancreosimin — stimulates contraction of the gallbladder and secretion of pancreatic enzymes; stimulates cell proliferation in the gallbladder, duodenum, and pancreatic islets.
• Gastroinhibiting peptide — suppresses the secretion of pepsinogen and hydrochloric acid, reduces gastric peristalsis, stimulates the secretion of insulin and intestinal juice.
• Enteroglucagon — its biological effects are in many ways similar to the action of glucagon.
• Motilin — рregulates the motility of the gastrointestinal tract, in particular; reduction of the sphincters of the esophagus and stomach during the interesophageal period.
• Neurotensin — enhances blood flow and peristalsis of the small intestine, suppresses the secretion of hydrochloric acid and insulin, stimulates the release of glucagon.
• Bombesin (gastrin-releasing peptide) — stimulates the secretion of gastrin; enhances the secretory activity of the pancreas, the motor activity of the intestine and gallbladder.
• Pancreatic polypeptide — suppresses the secretion of pancreatic juice, reduces the motility of the gallbladder.
• Secretin — stimulates the secretion of pancreatic juice rich in bicarbonates and enzymes, the secretion of duodenal glands and mucus in the stomach.
• Peptide YY— increases the formation of mucus by goblet cells.

The local and distant effects of GEP hormones can be similar or antagonistic, which together provides an optimal level of humoral regulation of the functioning of the gastrointestinal tract.