Prostaglandins: effects on the gastrointestinal tract.

Several prostaglandins have been shown to exert five major gastrointestinal actions. Inhibition of gastric acid secretion, orally and parenterally. Antiulcer activity (they prevent gastric and duodenal ulcers produced experimentally in animals, and they accelerate the rate of healing of duodenal ulcers in humans). Cytoprotection for the stomach, the small and the large intestine. Cytoprotection is defined as the property of many prostaglandins to protect the mucosa of the stomach and intestine from becoming inflamed and necrotic when this mucosa is exposed to noxious agents. Cytoprotection is separate from, and unrelated to, inhibition of gastric secretion. In humans, certain prostaglandins of the E type given at very low doses prevent gastric bleeding produced by aspirin and indomethacin. Stimulation of intestinal secretion, through increase of cyclic AMP formation. Stimulation of smooth muscle contraction. Certain prostaglandins are likely to be beneficial in the treatment of gastric ulcers, stress ulcers, duodenal ulcers, and perhaps gastritis and certain forms of inflammatory bowel disease.