The effect of supplementation with n-6 polyunsaturated fatty acids on 1-, 2- and 3-series prostaglandin F production by ovine uterine epithelial cells

Linoleic acid (LA, 18:2n-6) has variously been found to increase or inhibit synthesis of 2-series prostaglandins (PGs), derived from arachidonic acid (AA, 20:4n-6). γ-linolenic acid (GLA, 18:3n-6) containing oils are promoted to women for a variety of reproductive problems. Little is known concerning their actual effects on reproduction. We investigated the effects of LA, GLA and AA supplementation (25-100 μM) on basal and oxytocin (OT) stimulated production of 1-, 2- and-3 series PGs by uterine epithelial cells isolated from non-pregnant ewes, used as a model system to study endometrial PG production. PGF isomers were measured using radioimmunoassays following separation by high performance chromatography (HPLC). OT challenge increased the proportion of PGF2α in relation to PGF1α and PGF3α in control medium. LA supplementation decreased all PGF isomer production and reduced responsiveness to OT. GLA increased both absolute and proportional PGF1α production and slightly enhanced PGF2α generation. AA increased PGF2α generation and raised its isometric proportion. Both GLA and AA increased overall PGF output significantly but prevented the cells from responding to OT. These results suggest that consumption of LA and GLA are likely to differentially alter both uterine PG metabolism and responsiveness to OT. This may have implications for the control of a variety of reproductive processes.