Prostaglandin E2 (PGE2)

Prostaglandin E₂ () is a primary product of arachidonic acid metabolism in many cells. Like most eicosanoids, it does not exist preformed in any cellular reservoir. When cells are activated or exogenous free arachidonate is supplied, PGE₂ is synthesized de novo and released into the extracellular space. In vivo, PGE₂ is rapidly converted to an inactive metabolite (13,14-dihydro-15-keto PGE₂) by the prostaglandin 15-dehydrogenase pathway. The half-life of PGE₂ in the circulatory system is approximately 30 seconds and normal plasma levels are 3-12 pg/ml.  In general, urine and culture media samples can be diluted, if necessary, and added directly to the assay well. Plasma samples should be purified prior to use. Because of the rapid metabolism of PGE₂, the determination of in vivo PGE₂ biosynthesis is often best accomplished by the measurement of PGE₂ metabolites.