Prostaglandins are produced by the metabolism of arachidonic acid. Prostaglandin E2 is one of the five physiologically significant prostanoids known. Its wide spectrum of physiologic and pharmacologic effects in various tissues is mediated through binding to the Prostaglandin E2 receptors (EP1, EP2, EP3 & EP4). These include effects on the immune, endocrine, cardiovascular, renal and reproductive systems as well as smooth muscle. It is also one of the most abundant of the prostanoid f