Protective effects of the prostaglandins on the gastric mucosa.

Prostaglandins are a group of 20-carbon, oxygenated fatty acids derived from arachidonic acid. They are present in most mammalian cells and tissues, and since their half-life is short, they are considered to exert their actions in the tissues where they are produced. The gastrointestinal mucosa contains relatively large amounts of prostaglandin. Prostacyclin is the most common prostaglandin formed by the gastric mucosa, and this compound and prostaglandin E2, which is also present in the gastric mucosa, may affect gastric mucosal blood flow and acid secretion. Prostaglandins have been shown to protect against gastric and duodenal mucosal damage in animals and humans. This protection can occur independently of acid inhibition and may be direct or adaptive.