5-trans PGE2 occurs naturally in some gorgonian corals and is a common impurity in commercial lots of PGE1.{2213} It is 18 times more potent than PGE2 in activating adenylate cyclase in NCB-20 cell homogenates.{2180} 5-trans PGE2 accelerates fibrinolysis by enhancing plasminogen activation mediated by tissue-type plasminogen activator.{2177} It also inhibits platelet aggregation in human PRP with an IC50 of 180 nM.{1607}