SYNTHESIS OF PROSTAGLANDIN E-2 ETHANOLAMIDE FROM ANANDAMIDE BY CYCLOOXYGENASE-2

Because of its structural similarity to polyunsaturated fatty acids, a nandamide could serve as substrate for enzymes such as lipoxygenases a nd cyclooxygenases, which metabolize polyunsaturated fatty acids to po tent bioactive metabolites. Here the ability of recombinant human cycl ooxygenase-l (hCOX-1) and cyclooxygenase-2 (hCOX-2) to metabolize anan damide was studied. Baculovirus-expressed and -purified hCOX-2, but no t hCOX-1, effectively oxygenated anandamide. Reverse phase high pressu re liquid chromatography analysis of the products derived from 1-C-14- labeled anandamide showed that the products formed are similar to thos e formed with arachidonic acid as substrate. The major prostanoid prod uct derived from anandamide was determined by mass spectrometry to be prostaglandin E-2 ethanolamide. Incubation of anandamide with lysates and the intact cell line expressing COX-2 but not that of COX-1 produc ed prostaglandin E-2 ethanolamide. These results demonstrate the exist ence of a COX-a-mediated pathway for anandamide metabolism, and the me tabolites formed represent a novel class of prostaglandins.