19(R)-Hydroxy-prostaglandin E2

19(R)-Hydroxy-prostaglandin E2 is a PGE2 metabolite that acts as a potent smooth muscle relaxant and a selective EP2 receptor agonist, contrary to PGE2, which can activate a variety of prostanoid receptor types. Reportedly, this compound occurs at significant levels in human seminal vesicles, but levels may vary across individuals possibly due to polymorphic expression of prostaglandin enzymatic mechanisms. It was found that microsomes of seminal vesicles metabolize exogenous prostaglandin E2 into 19(R)-Hydroxy-prostaglandin E2. This product was observed to activate plasma membrane A cyclase (adenylyl cyclase) and hepatocyte glycogen phosphorylase in isolated rockfish, but did not stimulate an FP-receptor preparation like PGE2.