Protective effects of cysteamine on bovine oocytes matured in vitro with eicosapentaenoic acid (EPA): impact on early embryo development

NIKOLOFF, N.; CAMPAGNA, A; CARRANZA, ANA; ANCHORDOQUY JM; ANCHORDOQUY JP; FABRA M; PASCUA AM; SEOANE A; FURNUS CC

Simposio; International Ruminant Reproduction Symposyum; 2018

Data on fatty acid composition and their uptake and utilization by oocytes and embryos are relevant for culture in vitro, cryopreservation practices, and embryo quality improvement. Despite several studies in vitro suggesting enhanced embryo development with polyunsaturated fatty acids supplementation, results are not consistent and it would be important to determine which fatty acid is the most beneficial for embryo quality and survival (Santos et al., 2008). In vitro, embryos are sensitive to lipids effects unless adequate antioxidant protection is provided (Reis et al., 2003). The aim of this study was to determine the effect of eicosanopentaenoic acid (EPA; n-3, 20:5) alone or with cysteamine (CYS) on bovine oocyte during in vitro maturation (IVM). For this purpose, bovine cumulus-oocyte complexes (COC) from ovaries obtained in a slaughterhouse were matured in vitro in TCM- 199 supplemented with 0.1%essentially fatty acid?free BSA, 1 µg/mL FSH, 1 µg/mL estradiol 17ß at 39°C with 5% CO2 in humidified air. COCs were matured 24 h in IVM media: (1) alone (Control); (2) supplemented with 1 nM, 10 nM and 100 nM EPA and, (3) with EPA + Cysteamine 100 µM. Oocyte intracellular ROS level with H2DCFDA, cumulus expansion area with digitalizing images, nuclear maturation with Hoechst 33342, and embryo developmental capacity were evaluated. Data were analyzed using Statgraphics Plus 5.1 software. The results demonstrated that: a) ROS levels were significantly higher in oocytes matured with 1mM and 100 mM EPA compared with Control (P