Altering n-3 to n-6 polyunsaturated fatty acid ratios affects prostaglandin production by ovine uterine endometrium

Abstract Consumption of n-3 polyunsaturated fatty acids (PUFAs) is considered beneficial to health but effects on fertility remain uncertain. This study investigated the effect of n-3 PUFA supplementation on endometrial prostaglandin (PG) production. Ovine uterine endometrial cells were cultured to confluence in DMEM/F12 medium containing 10% foetal bovine serum. Stromal and epithelial cell populations were confirmed by immunocytochemistry. Cultures were supplemented with 0, 20 or 100 μM of α-linolenic acid (ALA), stearidonic acid (SDA), eicosapentaenoic acid (EPA) with lipopolysaccharide (LPS) at 0 and 0.1 μg/ml, or different combinations of EPA with arachidonic acid (AA) in serum-free medium for 24 h. PGs were quantified using radioimmunoassay and PG-endoperoxide synthase ( PTGS ) isoforms, PGE and PGF synthase (microsomal PGES1 and PGFS ) mRNAs by qPCR. LPS increased PGE 2 production significantly without changing PGF 2α production, causing increased PGE 2 :PGF 2α ratios. ALA and SDA increased PGE 2 , PGF 2α and PGE 2 :PGF 2α ratios ( P PTGS1 and PTGS2 mRNA expression and PGE 2 and PGF 2α production ( P P 2 :PGF 2α ratio was not affected by AA or EPA alone, but increased when these two PUFAs were combined ( P PTGS1 mRNA expression ( P PTGS2 expression. EPA and AA up-regulated mPGES1 expression ( P PGFS expression. Since AA is preferentially incorporated in uterine endometrium to produce 2-series PGs, alteration of PG production by EPA may affect many reproductive processes.