Abstract: To assess the histologic and physiological function of the cryopreserved ovarian tissues after autologous implantation in mesometrium, ovarian bursa and ovary in rabbits. Methods： Fifteen New Zealand White female rabbits were divided into three groups at random, with 5 rabbits in each group. Group 1,fresh ovarian tissues were implanted into mesometrium and ovarian bursa; group 2, cryopreserved ovarian tissues were implanted into mesometrium and ovarian bursa; group 3, cryopreserved ovarian tissues were implanted into ovary. The ovarian and endometrial histology, the survival and development of follicles were detected through light microscope and electron microscope. Vaginal cytology was used to assess the secretary function of implanted ovarian tissues. Results： No significant differences were observed in the proportion of normal and morphologically changed follicles between frozenthawed tissues and fresh ovarian tissues (P>0.05), between cryopreserved tissues and implanted cryopreserved tissues (frozenthawed group compared with group 2 or group3, P>0.05), and among implantation groups (Group 1, 2 and 3, P>0.05, Table 1). TheHJ]percentages of normal follicle in group 1, 2 and 3 were lower than those of the fresh ovarian tissues(P＜0.05). The implanted ovarian tissues in group 1,2,3 all resumed follicle development and no significant differences were observed in the proportion of maturescent follicles between the fresh ovarian tissues and three implanted groups(P＞0.05). The maturescent follicles in tissues of group 2 and 3 were more than those in frozenthawed tissues(P＜0.05). After cryopreservation and implantation, there were no evident changes in ovarian histology and ultrastructure. Conclusion: Cryopreservation of small pieces of ovarian tissues is feasible. After autologous implantation, the cryopreserved ovarian tissues have no significant morphological and ultrastructural changes, the follicles survive and develop well; Mesometrium, ovarian bursa and ovary are all favourable implantation sites.

Key words: Ovary, Implantation, Autologous, Rabbits