Protective effects of glycine, glutamine and taurine on the development of hamster embryos culture in abnormally high osmolarity madium

This experiment aims to find out the protective effects of glycine, glutamine, and taurine on the development of two-cell and eight-cell hamster embryos cultured in a chemical defined culture medium, HECM-10, at three osmolarity levels (275, 325 and 375 mOsmol). Two-cell and eight-cell embryos were randomly distributed among different culture media with either single or combinations of these amino acids and without these amino acids (the control group). Embryos were cultured for 48 hr. and the percentages of embryonic development were compared. Results showed that at 275 mOsmol with or without amino acids, two-cell embryos were not able to develop beyond the eight stage in vitro. However, the percentages of four-cell embryos in HECM-10 supplemented with glycine and glycine plus glutamine were significantly higher than that of the control group. Development of eight-cell embryos to blastocyst stage in HECM-10 supplemented with glutamine alone, glutamine plus taurine, and glycine plus glutamine at 275 mOsmol, after 48 hr. culture, were significantly higher than those in the control group. Blastocyst development was decreased in the high osmolarity medium (325 and 375 mOsmol) compared to 275 mOsmol. At 325 mOsmol, the percentages of blastocyst in medium containing taurine, glutamine and all three amino acids, after 48 hr. in culture, were higher than that of the control group. At 375 mOsmol, a number of eight-cell embryos developed to morula stage while just a few reach blastocyst stage. The percentages of morula in medium containing glutamine, taurine plus glutamine, glycine plus glutamine and all three amino acids were significantly higher than that of the control group. This study tend to indicate that glycine, glutamine and taurine were able to protect the development of two-cell and eight-cell embryos against the deleterious effect of high osmolarity medium to a certain limit. Hence they could possibly act as the osmoprotectant in abnormally high osmolarity medium.