Survival Rate of Preantral Follicles Derived From Vitrified Mouse Ovarian Tissue by Cryotop

Purpose: The aim of this study was to investigate the growth and survival rate of preantral follicles isolated from vitrified ovarian tissue by cryotop.Materials and Methods: Ovaries of 14-day-old NMRI mice were separated and divided into three groups fowling as: vitrified, toxicity tested and control groups. Ovaries in the experimental groups were immersed in equilibration and vitrification solution composed of ethylene glycol (EG), dimethylsulfoxide (DMSO) in HEPES-buffering tissue culture medium 199 (TCM 199) with human serum albumin(HSA), then in vitrification group ovaries loaded on cryotop and plunged into liquid nitrogen whereas in toxicity test group ovaries immediately were submitted to warming process. After three weeks the vitrified ovaries were warmed and Histological evaluation was performed. Preantral follicles from ovaries in three groups were isolated by mechanical dissection and isolated follicles were cultured for 4 days to compare survival rate and diameters of follicles between mentioned groups).Results: Survival rate in toxicity group (97.4%), alike the control group (98.7%) were significantly higher than the vitrification group (92.7%), (p<0.05). Increasing in follicles diameter after 4 days in vitrification group was significantly lower than the control and toxicity test groups (p<0.05).Conclusions: In spite of significantly difference in survival rate of preantral follicles between control and vitrification group, ovarian tissue vitrification by cryotop highly preserves the viability rate of the preantral follicles.