EVIDENCE THAT THE F-2-ISOPROSTANE, 8-EPI-PROSTAGLANDIN F2-ALPHA, IS FORMED IN-VIVO

F-2-isoprostanes are prostaglandin (PG)F-2-like compounds that are produced in vivo as non-enzymatic products of free radical catalyzed peroxidation of arachidonic acid. One F-2-isoprostane whose formation should be favored is 8-epi-PGF(2 alpha), 8-Epi-PGF(2 alpha) has been shown to exert potent bioactivity but proof that it is formed in vivo is lacking. Evidence is now presented suggesting that 8-epi-PGF(2 alpha) is, in fact, formed in vivo by demonstrating that an endogenous F-2-isoprostane with a retention time on capillary GC identical with that of 8-epi-PGF(2 alpha) co-chromatographs through four high resolving HPLC purification procedures with authentic radiolabelled 8-epi-PGF(2 alpha).