N, N-Dimethylglycine decreases oxidative stress and improves in vitro development of bovine embryos

The antioxidant effect of N, N-dimethylglycine (DMG) on in vitro-produced (IVP) bovine embryos was examined. After in vitro fertilization, presumptive zygotes were cultured with or without 0.1 mu M DMG under different oxygen tensions. The percentage of embryos developing to the blastocyst stage was lowest under a 20% oxygen concentration without DMG, and it was significantly increased (P < 0.05) by applying a 5% oxygen concentration. Under the 20% oxygen concentration, supplementation of the medium with DMG significantly improved blastocyst development, which was nearly equal to that achieved under 5% oxygen without DMG. Furthermore, a tendentious increase (P = 0.06) in blastocyst cell numbers was observed when DMG was applied. In the second experiment, addition of H2O2 (0.5 mM) to the culture medium significantly (P < 0.01) reduced the percentage of embryos developing to the blastocyst stage. However, DMG supplementation prevented this reduction. In conclusion, DMG enhanced the in vitro development of IVP bovine embryos by acting as an antioxidant.