Gastrointestinal hormones
Below is a brief summary of the major hormones involved in food digestion:
VIP: vasoactive intestinal peptide
| Source | Stimulus | Actions | |
|---|---|---|---|
Gastrin | G cells in antrum of the stomach | Distension of stomach, vagus nerves (mediated by gastrin-releasing peptide), luminal peptides/amino acids Inhibited by:
| Increase HCL, pepsinogen and IF secretion, increases gastric motility, stimulates parietal cell maturation |
CCK | I cells in upper small intestine | Partially digested proteins and triglycerides | Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying, trophic effect on pancreatic acinar cells, induces satiety |
Secretin | S cells in upper small intestine | Acidic chyme, fatty acids | Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells |
VIP | Small intestine, pancreas | Neural | Stimulates secretion by pancreas and intestines, inhibits acid secretion |
Somatostatin | D cells in the pancreas & stomach | Fat, bile salts and glucose in the intestinal lumen | Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, stimulates gastric mucous production & inhibits gastric emptying |
Terms
CCK: cholecystokininVIP: vasoactive intestinal peptide