Effects of antioxidants for the development of rat embryos in vitro

Rats are one of the most used species as model animal in medicine, physiology, biotechnology and biomedicine, and they have an important place especially in the development of human disease models. Rats are accepted as a good animal model for solving the problems in human embryology. Embryonic development of rat embryos cultured in vitro may pause at the 2- or 4- cell stages because of some reasons such as maternal zygotic transition (MZT) and culture conditions. Higher reactive oxygen species (ROS) levels, which are formed in culture conditions cause embryonic block in the 2- or 4-cell stages in rat embryos cultured in vitro. Culture media supplemented with antioxidants may help to reduce ROS formation in embryo culture and to overcome embryonic block in this way. Resveratrol, which is the most popular antioxidant recently, and Ascorbic acid, which has proven antioxidant activity, have not been used before in in vitro culture of pre-implantation rat embryos. These antioxidants were tried and compared for the first time in this thesis. In this thesis, the effects of antioxidants supplemented in KSOM-R media were examined for reducing the negative effects of ROS on 1-cell rat embryos cultured in vitro. There were 5 groups; control, Ascorbic acid 50 µM, Ascorbic acid 100 µM, Resveratrol 0.25 µM and Resveratrol 0.50 µM. The study was repeated four times. There were differences significantly between Ascorbic acid 50 µM and both control and Ascorbic acid 100 µM groups in cleavage rates. There was differences significantly between Ascorbic acid 50 µM and both Ascorbic Acid 100 µM and Resveratrol 0.25 µM groups in total development (p˂0.05). Statistical analysis of the data showed no significant differences in degenerated/fragmented cell rates between all the groups (p>0.05). Although the special culture needs for the rat embryos in different stages and the embryonic development success of various strains are the obstacles to designing an optimal culture medium and supplementing culture media such as KSOM-R and mR1ECM with antioxidants may be beneficial. It can be concluded that Ascorbic acid supplementation in rat embryo culture media for culturing 1-cell rat embryos from different strains will contribute to the development of embryos.