Production of reactive oxygen species by spermatozoa undergoing cooling, freezing, and thawing

• Published in: Molecular reproduction and development 2001-08, Vol.59 (4), p.451-458
• Main Authors: Chatterjee, Suvro, Gagnon, Claude
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cattle; Cell physiology; Cryopreservation; Cryoprotective Agents - chemistry; Cryoprotective Agents - metabolism; Effects of physical and chemical agents; Electron Spin Resonance Spectroscopy; Fundamental and applied biological sciences. Psychology; Hydrogen Peroxide - metabolism; lipid peroxidation; Male; membrane fluidity; Membrane Fluidity - physiology; Molecular and cellular biology; nitric oxide; Nitric Oxide - metabolism; Reactive Oxygen Species - metabolism; Spermatozoa - physiology; Spin Trapping; superoxide
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.1052

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°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. © 2001 Wiley‐Liss, Inc.