title: Conjugated linoleic acid decreases prostaglandin synthesis in bovine luteal cells in vitro.
abstract: Feeding conjugated linoleic acids (CLA) improves reproductive performance in dairy cows; however, the molecular mechanisms by which CLA improves reproduction are not understood. The effect of the CLA isomers, trans-10, cis-12 CLA and cis-9, trans-11 CLA on synthesis of progesterone, PGE(2) , and PGF(2α) , in bovine luteal cells was determined in this study. Luteal cells from three cows were cultured in medium containing 0 or 0.1 µM of trans-10, cis-12 CLA and cis-9, trans-11 CLA in varying ratios in the presence and absence of 1 µM of forskolin. Prostaglandin and progesterone concentrations were not altered by CLA isomer and ratio. Luteal cells cultured in the presence of CLA had lower PGF(2α) concentrations (62.6 ± 13.4 pg/ml vs. 55.7 ± 12.2 pg/ml; P = 0.005) and, in the absence of forskolin, lower PGE(2) concentrations (65.3 ± 15.1 pg/ml vs. 32.4 ± 14.1 pg/ml; P = 0.002) in culture media, while progesterone concentrations were not altered (P = 0.63). Relative steady-state mRNA amounts of COX-2 (1.7-fold decrease; P = 0.002), PGE synthase (1.5-fold decrease; P = 0.03) and 3β-hydroxysteroid dehydrogenase (1.6-fold decrease; P = 0.0003) were lower in CLA-treated cultures, but CLA did not significantly alter mRNA amounts of PGE(2) 9-keto-reductase, StAR, and cytochrome P450 side chain cleavage enzyme. In conclusion, a potential mechanism exists by which trans-10, cis-12 CLA and cis-9, trans-11 CLA may improve reproductive performance in dairy cows, by suppressing PGF(2α) synthesis in luteal cells via attenuation of COX-2 gene expression.
authors.affiliation: Department of Animal Sciences, Oregon State University, 112 Withycombe, Corvallis, OR 97331, USA.
authors.forename: Katherine C P
authors.initials: KC
authors.lastname: May
authors.forename: Gerd
authors.initials: G
authors.lastname: Bobe
authors.forename: Chad J
authors.initials: CJ
authors.lastname: Mueller
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Cannon
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics; D052246:Cyclooxygenase 2 Inhibitors; D003612:Dairying; D005260:Female; D044243:Linoleic Acids, Conjugated / Q000378:metabolism / Q000494:pharmacology*; D008184:Luteal Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011374:Progesterone / Q000096:biosynthesis; D011453:Prostaglandins / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D044243:Linoleic Acids, Conjugated; D011453:Prostaglandins; D012333:RNA, Messenger; D011374:Progesterone; D051546:Cyclooxygenase 2