Damage of Granusola and Stroma Cells Exposed to Mouse Ovarian Tissue Cryopreservation: Potential Mechanism of Ovarian Injury.

BACKGROUND: Several obstacles must be overcome before ovarian tissue cryopreservation can be used as a standard procedure. OBJECTIVE: To carry out a morphologic and functional study of the effect of cryopreservation on mouse follicles and stroma cells. MATERIALS AND METHODS: Female mice were divided into three groups (control, fresh graft and cryopreserved graft). Ultrastructural features of follicles and stroma cells were evaluated using transmission electron microscopy. After autologous transplantation, micro-vessel densities of grafts were examined. RESULTS: Vacuoles in granulosa cells and stromal cells are significantly greater than that of oocytes. The microvessel density of fresh grafts is significantly higher than that in frozen-thawed grafts. CONCLUSION: Granusola and stroma cells, rather than oocytes, are vulnerable to cryoinjury. Injuries to granulosa cells and stromal cells could be the critical part of ovarian damage caused by cryopreservation.