prostaglandin E2

(PGE₂) an important prostaglandin produced in the renal medulla, gastrointestinal mucosa, and other tissues; it causes renal vasodilation and inhibition of renal tubular sodium resorption, inhibition of gastric secretion, and either contraction or relaxation of smooth muscle (depending on the tissue). It is also released by macrophages and modulates several inflammatory responses; it increases vascular permeability, increases pain sensitivity, is pyrogenic, and suppresses lymphocyte transformation, release of mediators from mast cells, and cell-mediated cytotoxicity. PGE₂ produced by some tumors causes hypercalcemia by stimulation of bone resorption by osteoclasts. When used pharmaceutically its nonproprietary name is dinoprostone.