Schematic for the study design. a The experimental scheme of the determination the optimum perfusion flow. b The rats were divided into three groups: fresh control group, CS group, HMP group, respectively. The preservation solution contains Dulbecco’s modified Eagle’s medium/Ham’s F-12(1:1, v/v), 10% fetal bovine serum, 10 μg/ml insulin, 10 μg/ml transferrin, and 50 mlU/ml follicle-stimulating hormone (FSH). c Duration of operation in two groups