Effects of taurine on human embryo development in vitro

Glutamine and taurine are reported to be beneficial for mouse embryo develo pment in vitro, and we have recently shown that glutamine improves human bl astocyst formation in vitro, This randomized study compared the development of supernumerary human embryos in the presence of 1 mmol/l glutamine and/o r 5 mmol/l taurine from the 2-4-cell stage to the blastocyst stage. Blastoc yst development and cell numbers were similar in the presence of glutamine or taurine: 52.6% and 58.3% of the embryos reached the blastocyst stage, re spectively. Pyruvate uptake was similar in the presence of glutamine or tau rine throughout development, as was lactate production after the 8-cell sta ge. Before this stage, lactate production was 4-fold higher in the presence of taurine (P < 0.001). The proportion of embryos reaching the blastocyst stage was similar with glutamine alone or with glutamine and taurine (62.5% and 47.2% respectively), as were the blastocyst cell numbers (63.0 +/- 4.6 and 61.0 +/- 5.1 respectively). In conclusion, taurine supports developmen t of 24-cell human embryos to the blastocyst stage, although it does not fu rther augment the beneficial effects of glutamine.