摘要
Sperm cryopreservation is an effective method of maintaining valuable strains for biomedical research. However, successful cryopreservation of rat spermatozoa remains a challenge. The objective of this study was to determine if OptiPrepTM (60% iodixanol in water) acts as a protectant during Sprague Dawley (SD) rat sperm cryopreservation. We first evaluated OptiPrepTM concentration effect on sperm motility 10 min and 3 h after freezing-thawing. Acrosomal integrity and mitochondrial membrane potential (MMP) were also evaluated for frozen-thawed spermatozoa. In addition, the toxic effects of OptiPrepTM were tested via motility after 1 h or 3 h incubation with OptiPrepTM in fresh and chilled rat spermatozoa. The concentrations of OptiPrepTM used for these studies were 0% (control), 1%, 2%, 3%, and 4% (v/v). There were no significant differences on motility among OptiPrepTM treatment groups in fresh and chilled rat spermatozoa. OptiPrepTM did not have toxic effect on SD rat spermatozoa. In frozen-thawed samples, 2% OptiPrepTM improved total motility at 10 min after thawing and progressive motility and average path velocity at 3 h after thawing (P < 0.05) and MMP (P < 0.05) while OptiPrepTM did not show difference for acrosomal integrity compared to control. Intra uterine insemination (IUI) was performed for OptiPrepTM -contained cryopreserved spermatozoa showing best results on sperm evaluation parameters. While 9 out of 10 (90%) rats become pregnant after intrauterine insemination (IUI), 4 out of 11 (36%) rats become pregnant after IUI using frozen-thaw SD sperm. These data suggest that iodixanol may have cryoprotective effect during rat sperm freezing without any toxic effects.Source of funding: This work was supported by the NIH National Center for Research Resources grants R21 RR025913-02Conflict of interest: None declared.