Abstract
This study was designed to investigate the effects of applying 1 mT static magnetic field (SMF) during the vitrification process, on the viability of ovarian follicles after vitrification-warming and autotransplantation. The study was conducted in two phases. In the first phase, ovaries of female NMRI mice (6 to 8 weeks old) were randomly divided into three groups: 1- Freshly isolated ovaries fixed in Bouin solution (control group), 2- Ovaries vitrified-warmed without exposure to magnetic field (V1 group) and 3- Ovaries exposed to magnetic field during equilibration step of the vitrification process (V2 group). In the second phase, the vitrified (V1 and V2 groups) and fresh ovarian tissues were autografted into the back muscles of the mice from which the ovaries were extracted. In both phases, morphological aspects and molecular characteristics of active-apoptotic caspase-3 antibody were evaluated. Results indicated the lower percentages of morphologically intact primordial, primary and antral follicles in the V1 group (67.6, 49.5 and 17.6%, respectively) than those of control (97.3, 85.4 and 42.1%, respectively) and V2 (94.1, 78.8 and 40.9%, respectively) groups. In addition, the mean percentages of morphologically intact follicles in the V1 group were statistically lower than those in other groups, after transplantation. The rate of apoptosis in preantral follicles of the V1 group was significantly higher than that in the other groups. It was concluded that exposure of mice ovaries to SMF during vitrification resulted in greater resistance to injuries.