Effects of HMG on revascularization and follicular survival in heterotopic autotransplants of mouse ovarian tissue

Ovarian tissue transplantation is now considered as a procedure to preserve the fertility of young women patients undergoing cancer therapy. The present study investigated the effects and mechanism of human menopausal gonadotrophin (HMG) intervention on vascular remoulding in ovarian heterotopic autotransplantation. Ovaries of 8-week-old mice were cultured in vitro with different concentrations of HMG for 3 h for measuring the expression of vascular endothelial growth factor (VEGF). The cultured ovaries were implanted under the kidney capsule and removed 24, 36, 48 h or 1 month after transplantation. Revascularization, fluid exudation and the number of surviving ovarian follicles were observed. The results showed that VEGF was increased 1.6–6.5 times in the HMG intervention groups. Revascularization appeared 24–36 h after transplantation and was earlier than that of the control. Fluid exudation increased incrementally with increasing HMG concentrations. The total number of surviving ovarian follicles was increased by 1.2–1.5 times in the HMG 0.15 IU/ml group as compared with the other groups 1 month after transplantation. It is concluded that intervention with HMG in vitro before transplantation could improve the blood supply reconstruction and survival of the autotransplanted ovarian follicles, which might be associated with increased VEGF expression.Early diagnosis and effective therapy have been improving the long-term survival rate of children, adolescents and young women suffering from malignant tumours. Chemotherapy and/or radiation therapy commonly compromise the ovary functions. Cryopreservation of cortical fragments of ovarian tissue before cancer therapy, followed by later transplantation, is an emerging technique, but ischaemia after transplantation appears to be one of the main obstacles to successful transplantation. The aim of the present study was to investigate the effects of human menopausal gonadotrophin (HMG) on revascularization and follicular survival of autotransplanted ovary. Half ovaries of 8-week-old mice were cultured in vitro with different concentrations of HMG (0.00, 0.15, 0.30 and 0.60 IU/ml) for 3 h and transplanted back to the mice. The expression of vascular endothelial growth factor (VEGF), blood vessel repatency and survival ovarian follicles were observed. We found that the in vitro intervention of HMG could improve expression of VEGF in ovarian tissue, shorten the blood supply reconstruction time and increase the number of survival ovarian follicles. The starting date of the oestrous cycle was significantly earlier in the HMG 0.60 IU/ml treatment group than the HMG 0.00 IU/ml group. We also found that treatment with HMG 0.15 IU/ml was better in preserving ovarian follicle numbers than HMG 0.30 or 0.60 IU/ml. We concluded the intervention of HMG in vitro before transplantation could improve the blood supply reconstruction and survival of the autotransplanted ovarian follicles, which might be associated with increased VEGF expression. This method may have the potential for clinical usage.