ABSTRACT
BACKGROUND: Transplantation of fragments of ovarian cortex is performed without vascular reanastomosis, therefore, to increase the tolerance of ovarian tissue to the freezing-thawing and ischemic injuries is critical for follicular survival and functional longevity of the graft.OBJECTIVE: To investigate the effect of follicle stimulating hormone (FSH) on the morphological and function of sheep ovary tissue in the process of cryopreservation, so that to provide new freezing method for human ovary tissues. METHODS: Healthy BALB/c strain female nude mice were equally and randomly divided into 3 groups and subjected to heterotopic transplantation of fragments of sheep ovarian cortex. (1) Control group: transplantation following sampling; (2) experimental group: transplantation following freezing-thawing, and the solution was free of FSH; (3) FSH group: the freezing and thawing and culture fluid contained FSH. The estrous cycle recovering rate, estrous cycle recovering time, the number of follicle were observed following transplantation. The histological changes, and the level of E2 in blood serum were observed at 4 weeks after transplantation.RESULTS AND CONCLUSION: There were no significant differences in estrous cycle recovering rate and number of follicle/PHF between FSH and control groups (P> 0.05), but the number of follicle was greater than the experimental group (P< 0.05). Moreover, the time of estrous cycle recovering in FSH group was similar to control group, but shorter than experimental group (P < 0.05). There were more developing follicular in FSH group, but few in experimental group at 4 weeks. No significant difference was detected in E2 level in blood serum between FSH and control group (P > 0.05), but significantly greater than the experimental group (P< 0.05). Results show that FSH addition in vitrification fluid can improve ovarian follicle survival following cryopreserved sheep ovary tissue transplantation.