Effect of Cryopreservation on Rat Sperm DNA and involvement of elevated Oxidative Stress, Apoptosis – A Review

Abstract

Current article explains about the effects of cryopreservation on testicular sperm DNA. Conservation of sperms has several purposes in artificial reproductive technologies (ART), species conservation and clinical medicine. Despite of various advances in cryopreservation methodology, the recovery rate of functional post thawed spermatozoa remains mediocre, with sperm motility being significantly decreased after freezing. Sperm cryopreservation and storage facility currently require liquid nitrogen method for long or short term storage. The combinations of sperm storage involved are temperature, cooling rate, chemical composition of the extender, cryoprotectant concentration, reactive oxygen species (ROS), seminal plasma composition and hygienic control factors that affect the life-span of spermatozoa. The lack of structural integrity to sperm and damage to DNA of sperm shall have a significant negative impact on oocyte fertilization, embryo development rate, and live-birth rate. Hence the research conducted as on today conclude that cryopreservation of testicular spermatozoa may reduce DNA life expectancy; therefore scientists are yet in a position to rectify this troubleshoot for ultimate shell of life of DNA for prolonged periods without damage. This review describes about the effect of oxidative stress and apoptosis as one of the possible mechanisms involved in sperm cryoinjury.