P-121: Follicle Development in Vitrified Sheep Ovarian Tissue Transplanted to Immunodeficiencent Rat

Background: Ovarian cortex xenotransplantation into immunodeficient rats is a follicles protection method in rare animals and investigation on folliclogenesis. The aim of this study was to evaluate the effects of gonadotropin and erythropoietin (EPO) treatment on follicular development in the transplanted ovaries. Materials and Methods: Prepared sheep ovarian cortical strips were vitrified by cryopin method using combination of etilenglycol (EG) and dimetylsulfoxide (DMSO) as cryoprotectans.Vitrified-warmed strips were grafted in the neck muscle of castrated male rats that treated with or without EPO for 5 days. 14 days later, rats were treated with HMG for 9 weeks. Ovarian fragments from each animal were divided into the control (fresh ovarian tissue) and experimental groups (XI: vitrified xenograft+ HMG), (XII: vitrified xenograft+ HMG+ EPO). XI and XII groups were carried out for 11weeks and were repeated 7 times. E2 serum was measured before and after gonadectomy and at the end of xenograft. Histological analysis was done before and after grafting. Results: In all grafted tissues, follicular growth was decreased. The number of primordial and preantral follicles increased after transplantation in XII group as compared to the control group (44.19 ± 11.40, 10.20 ± 3.79 vs. 41.33 ± 2.86, 3.18 ± 0.57). In XI group the primordial follicles numbers was decreased after transplantation as compared to the control group whereas the preantral follicles were increased (38.13±12.12, 19.94 ± 11.82 vs. 41.33 ± 2.86 3.18 ± 0.57, respectively). E2 secretion were also increased in xenograft+ HMG+ EPO group and it showed a significant differences with male castrated rat (p<0.01) and xenograft+ HMG group, p<0.05). Conclusion: Co administration of human menopausal gonadotropin (HMG) and EPO seems to be more effective in surviving the primordial follicles in xenotransplanted vitrified ovaries.