Glutamine and hypotaurine improves intracellular oxidative status andin vitrodevelopment of porcine preimplantation embryos

Abstract

SummaryWe previously developed anin vitro-production system for porcine embryos and reported that the addition of glutamine (Gln) and hypotaurine (HT) duringin vitroculture improved embryo development. This study examined the effects of Gln and HT onin vitrodevelopment, intracellular oxidative status and DNA damage of porcine preimplantation embryos. Porcine zygotes produced byin vitromaturation (IVM) andin vitrofertilization (IVF) were cultured until day 2 (day 0 = day of IVF) in porcine zygote medium (PZM) including 2 mM Gln and 5 mM HT, namely PZM-5. On day 2, the cleaved embryos were selected and cultured for 24 h in PZM-5 to which one of the following substances was added: (1) none (control); (2) Gln; (3) HT; or (4) Gln + HT. After 24 h of culture in each medium, the embryos were then returned to PZM-5 and cultured until day 5. Day-5 blastocyst yield was significantly higher in the Gln and Gln + HT groups (p< 0.05) than in the control and HT groups. In addition, Gln + HT significantly increased the total number of cells in blastocysts (p< 0.05) compared with the control. Although the number of cells and the intracellular GSH levels in day-3 cleaved embryos did not differ among treatments, addition of Gln, HT or Gln + HT significantly (p< 0.05) reduced the intracellular H2O2content and the extent of DNA damage compared with the control. These results indicate that the presence of Gln and HT in PZM-5 from day 2 to day 3 promotes the development of porcine embryos by improvement of intracellular oxidative status.