Production of reactive oxygen species by spermatozoa undergoing cooling, freezing, and thawing.
In the present study, we provide evidence for the production of reactive oxygen species (ROS) during cryopreservation of bovine spermatozoa. Cooling and thawing of spermatozoa cause an increase in the generation of superoxide radicals. Although nitric oxide production remains unaltered during sperm cooling from 22-4 degrees C, a sudden burst of nitric oxide radicals is observed during thawing. Increase in lipid peroxidation levels have been observed in frozen/thawed spermatozoa and appears to be associated with a reduction in sperm membrane fluidity as detected by spin labeling studies. The data presented provide strong evidence that oxygen free radicals are produced during freezing and thawing of bovine spermatozoa and suggest that these reactive oxygen species may be a cause for the decrease in sperm function following cryopreservation. Mol. Reprod. Dev. 59: 451-458, 2001.
Chatterjee
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Urology Research Laboratory, Royal Victoria Hospital, Faculty of Medicine, McGill University, Montreal, Canada.
Gagnon
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C
D000818:Animals; D002417:Cattle; D015925:Cryopreservation; D003451:Cryoprotective Agents / Q000737:chemistry / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D008560:Membrane Fluidity / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013094:Spermatozoa / Q000502:physiology*; D019097:Spin Trapping
D003451:Cryoprotective Agents; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D006861:Hydrogen Peroxide