FORMATION AND METABOLISM OF 14,15-EPOXYEICOSATRIENOIC ACID BY HUMAN REPRODUCTIVE TISSUES

Human granulosa-luteal cells cultured in the presence of arachidonic a cid produced low levels of the epoxygenase metabolite 14,15-epoxy-5,8, 11-(Z,ZZ)-eicosatrienoic acid (14,15-EpETrE) as determined by HPLC ana lysis and gas chromatography mass spectrometry. When authentic 14,15-[ H-3]EpETrE was incubated with these cells in the absence of serum it w as metabolised initially to the dihydroxy derivative (14,15-dihydroxy- 5,8,11-eicosatrienoic acid, 14,15-DiHETrE) and subsequently to a numbe r of more polar metabolites as determined by HPLC. Fetal calf serum pr otected 14,15-EpETrE from metabolism for at least 2 h. A similar patte rn of metabolism was obtained when 14,15-[H-3]EpETrE was incubated wit h a human choriocarcinoma cell line (BeWo). Microsomes from this cell line converted arachidonic acid to a large number of radioactive metab olites including 14, 15-DiHETrE and 11,12-DiHETrE although there was n o evidence for the parent epoxides. These results extend earlier findi ngs that human reproductive tissues produce epoxygenase metabolites, a nd demonstrate the rapid metabolism of these compounds by intact cells in the absence of serum.