Roles of Cyclooxygenase, Prostaglandin E2 and EP Receptors in Mucosal Protection and Ulcer Healing in the Gastrointestinal Tract.

Roles of Cyclooxygenase, Prostaglandin E2 and EP Receptors in Mucosal Protection and Ulcer Healing in the Gastrointestinal Tract. Curr Pharm Des. 2018 Jun 28;: Authors: Takeuchi K, Amagase K Abstract Endogenous prostaglandins (PGs), produced from arachidonic acid by the two isoforms of cyclooxygenase (COX), play a pivotal role in maintaining mucosal integrity by modulating various functions of the gastrointestinal (GI) tract, and PGE2 is most effective in these actions. The PGE2 receptor is classified into 4 specific G-protein coupled subtypes, EP1-EP4, and their distribution accounts for the multiple effects of this prostanoid. PGE2 prevents acid-reflux esophagitis and indomethacin-induced gastric lesions through EP1 receptors, while endogenous PGs protect the stomach against cold restraint stress mediated by mainly PGI2/IP receptors and partly EP4 receptors. PGE2 also exhibits a protective effect against acid-induced duodenal damage and indomethacin-induced small intestinal lesions mediated by EP3/EP4 receptors; these effects in the stomach, duodenum, or small intestine are associated functionally with inhibition of gastric contraction (EP1), stimulation of duodenal HCO3- secretion (EP3/EP4), or suppression of bacterial invasion due to the inhibition of intestinal motility (EP4) as well as stimulation of mucus secretion (EP3/EP4), respectively. PGE2 also prevents ischemia-induced enteritis and dextran sulfate sodium-induced colitis...
Source: Current Pharmaceutical Design - Category: Drugs & Pharmacology Authors: Tags: Curr Pharm Des Source Type: research