Effect of galactose and fructose as replacement of glucose in culture medium on the development of 2- cell mouse embryos in vitro

Background and Ënergy sources play an important role in preimplantation development. Ëffect of glucose, an importamt energy source, has been studied in different stages of embryo development. Ënergy sources play important role in embryos development in preimplantation peroid. Glucose is one of the main sources of energy supply, and it’s effect has been studied in different stages of embryo development. Since fructose and galactose are the important isomers of glucose, thus in addition to the effect of glucose, its isomers were compared on the development of mouse embryos. 4-6 weeks old swiss mice were supravulated by HMG and HÇG hormones. The mice were killed 48- 50h after last injection and 2- cell embryos were collected by flashing. The embryos were cultured randomly to hatching stage using T6 medium with glucose (T6+gl), galactose(T6+ gal), fructose(T6+fr) and without hexose(T6-h). The percentages of embryos reached to blastocyst were 91.25, 67. 09, 92.85 and 70. 92 respectivly. Âlso, 40.82, 25.21, 42.85 and 23.46 percent of embryos were hatched after 72h of culture respectively. The percentages of blastocyst and hatching embryos in T6+gl and T6+fr were significantly greater than those in T6+gal and T6-h (p<0.0001), but there were no obvious differences between embyos cultured in T6+gal and T6–h and those cultured in T6+gl and T6+fr in reaching to blastocyst and hatching stages.Çonclusion : The results indicate that galactose can not be a proper replacement for glucose in primary embryos medium. But fructose can be an alternate for glucose in the medium, without causing any disorder in embryo development compared to glucose. But despite of this phenomenon, use of fructose as an alternate of glucose needs more studies.