Increased conjugated linoleic acid (CLA) consumption can affect the n-6 polyunsaturated fatty acid metabolic pathway for the biosynthesis of eicosanoids. Recent findings suggest that not only does CLA affect many different pathways, but that individual isomers of CLA act differently. Cultures derived from fetal endometrium grew more rapidly and were more viable after subculturing and cryopreservation than were adult-derived cultures. This study was designed to test the effects of two CLA isomers on PGF2α and PGE2 production in cultured fetal uterine endometrial cells. Fresh fetal reproductive tracts from fetuses in approximately the last month of gestation were obtained from gravid uteri at a local abattoir and endometrial cells collected by enzymatic dispersion. Confluent cells were exposed for 24h to 0, 50, 100, and 200 μM of c9, t11 CLA (CLA-1) or t10, c12 CLA (CLA-2). The results of this study show that the CLA isomers reduced PGF2α and PGE2 production, which are similar to finding in other tissues, as reported by Cheng et al.[1] and Nakanishi et al. [2] for PGF2α and PGE2 production, respectively. CLA-1 decreased PGF2α production in a dose depend manner (P<0.001; 6.84, 4.83, 3.40, and 2.24 ± 0.39 ng/ml, respectively). PGF2α production also decreased with CLA-2 supplementation (P<0.001; 7.16, 2.33, 2.61, and 1.99 ± 0.18 ng/ml, respectively). CLA-2 was more potent in reducing PGF2α production than CLA-1. PGE2 production decreased linearly after supplementation of CLA-1 (P<0.001; 327.82, 149.56, 127.54, and 59.01 ± 17.38 ng/ml, respectively). CLA-2 also decreased PGE2 production in the cultured endometrial cells (P<0.001; 313.05, 51.84, 56.72, and 37.05 ± 18.32 ng/ml, respectively) but the decrease was not linear and with any amount PGE2 production was decreased compared with controls (P<0.001). The PGE2 to PGF2α ratio was significantly reduced by both CLA isomers. In conclusion, results from this experiment demonstrate that in vitro supplementation of the CLA isomers significantly decreases PGF2α and PGE2 production in cultured fetal uterine endometrial cells. Inhibiting uterine secretion of PGF2α by feeding CLA isomers may delay regression of the CL and increase fertility rates through improved embryo survival.

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