RESUMEN
BACKGROUND: The purpose of this study was to investigate the in vitro survival and developmental potential of oocytes obtained from vitrified mouse ovaries transplanted to a heterotopic site. MATERIALS AND METHODS: In this experimental study, two-week-old mice were unilaterally ovariectomized after anesthesia. The ovaries were vitrified by cryotop. After two weeks, the ovaries were thawed and autotransplanted to the gluteus muscle tissue. Three weeks later the mice were killed, after which we removed and dissected the transplanted and opposite right ovaries. Cumulus oocyte complexes (COCs) and denuded oocytes were evaluated for in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro development (IVD). The control group consisted of sevenweek- old age-matched mice ovaries. RESULTS: All vitrified-transplanted (Vit-trans) ovaries contained some oocytes that survived. Following IVM, IVF and IVD, there were 41.7% out of 12 cultured zygotes that reached the 8-cell stage. CONCLUSION: Our experiment supports the progressive role of long-term graft survival after wholeovarian cryopreservation by vitrification and subsequent heterotopic transplantation. It is possible to recover viable follicles and oocytes that have the ability to develop in vitro.
RESUMEN
Purpose: The aim of this study was to investigate the survival and development of premature follicles and oocytes from a vitrified-transplanted ovary in a murine experimental model. Methods: The 14-day-old mice were unilaterally ovariectomized and the separated ovaries were vitrified by cryotop. After 2 weeks the ovaries were warmed and autotransplanted into the gluteus superfiscialis muscle. After 3 weeks, these ovaries (vit-trans), the ovaries from the opposite side (OPP), and 7-week fresh mouse ovaries as sham and control group (7 week-fresh), were recovered and examined histologically and by TUNEL test. Results: All 4 vitrified-autotransplanted ovaries had developing follicles. Primordial, primary, preantral and antral follicles were found in all three groups (7 week-fresh, OPP and vit-trans). The rate of apoptosis by TUNEL test was similar in all groups and no significant difference was found between vitrified-transplanted ovarian tissue and controls. Conclusions: These data demonstrate successful autotransplantation of vitrified whole mouse ovaries, manifested by the presence of all stages of folliculogenesis. According to the results of this experiment, heterotopic autotransplantation of whole cryopreserved ovary provides the opportunity for follicle development at all stages. However, further experiments are required to improve the efficiency of autotransplantation of cryopreserved ovaries to obtain better results.