Effect of dietary n-3 polyunsaturated fatty acid rich fish oil on the endometrial prostaglandin production in the doe (Capra hircus).

Recently, we showed that dietary supplementation of n-3 PUFA rich fish oil (FO) decreased the metabolites of serum prostaglandin (PG) F _2α and E ₂ during the window of pregnancy recognition in the doe. In this study, we investigated its effect on the changes on endometrial PG production in vitro. Cycling does (n = 12) of Rohilkhand region were divided into two equal groups and fed a concentrate diet supplemented with either FO containing 26% n-3 PUFA (TRT; n = 6) or palm oil (CON; n = 6) @ 0.6 mL/kg body weight for 57 days. Estrus was synchronized by two injections of PGF _2α analogue viz, on day 25 and 36 of supplementation and laparo-hysterotomy was performed to obtain endometrial tissue on day 16 of the synchronized estrus. Endometrial explant culture was done using a defined medium.The basal PG production was assayed at 6 and 12 h. Endometrial explant was stimulated with oxytocin (OXT) and/or recombinant ovine interferon tau (roIFN-τ) and PGs were assayed at 3 and 12 h post-treatment. The relative expression of genes related to PG metabolism in the endometrium was done by Quantitative Real Time PCR technique (qRT-PCR). There was a significant (P < 0.05) decline in the basal production of PGF _2α and PGE ₂ in the TRT as compared to the CON group. The cultured endometrial tissue produced PGF _2α in a time- dependent fashion in both the groups (P < 0.05). Neither OXT nor roIFN-τ had a significant (P > 0.05) effect on the PGF _2α and PGE ₂ production in the TRT group. Similarly, the PG production in the OXT and roIFN-τ was comparable with the control in TRT. Expression of mRNA for cyclooxygenase-2 (COX-2), cytosolic phospholipase A ₂ (cPLA ₂ ) and PGF synthase (PGFS) was lower (P < 0.05) whereas, PGE synthase and peroxisome proliferator-activated receptors such as PPAR-γ and δ was increased (P < 0.05) in n-3 PUFA fed doe. In conclusion, dietary supplementation of FO decreased the endometrial production of PGF _2α and PGE ₂ by downregulating the COX-2, cPLA ₂ and PGFS transcripts in the doe. The findings suggest that n-3 PUFA influence embryo survival by modulating the endometrial PG.
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