Osmotic stress induces oxidative cell damage to rhesus macaque spermatozoa.
Cryopreservation introduces extreme temperature and osmolality changes that impart lethal and sublethal effects on spermatozoa survival. Additionally, evidence indicates that the osmotic stress induced by cryopreservation causes oxidative stress to spermatozoa as well. Our objective was to determine the effect of reactive oxygen species (ROS) on rhesus macaque (Macaca mulatta) sperm function and to determine whether osmotic stress elicits the production of ROS. In the first experiment, the xanthine-xanthine oxidase (X-XO) system was used to generate the ROS superoxide anion (O(2)(-.)) and hydrogen peroxide (H(2)O(2)) in the presence or absence of the ROS scavengers superoxide dismutase and catalase, respectively. In the second experiment, osmotic stress was introduced by incubation of spermatozoa in a series of anisosmotic media ranging from 100 to 1000 mOsmol/kg in the presence or absence of the antioxidant alpha-tocopherol. Treatment with the X-XO system resulted in a significant increase in the generation of O(2)(-.) and H(2)O(2) that was detectable using flow cytometry. The ROS generated by the X-XO system was dose dependent, and as the concentration of ROS increased, motility decreased and lipid peroxidation increased while no affect was observed on viability. Incubation of spermatozoa in anisosmotic media also resulted in an increase in O(2)(-.) generation and lipid peroxidation that was significantly decreased in the presence of the powerful antioxidant alpha-tocopherol. These results clearly indicate that osmotic stress causes oxidative stress in rhesus macaque spermatozoa, which strongly supports the hypothesis that cryopreservation-induced osmotic stress may lead to oxidative cell damage.
Departments of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA.
Megan J
MJ
McCarthy
Julie
J
Baumber
Philip H
PH
Kass
Stuart A
SA
Meyers
D000818:Animals; D002374:Catalase; D016923:Cell Death / Q000502:physiology; D015925:Cryopreservation / Q000662:veterinary; D006861:Hydrogen Peroxide / Q000378:metabolism; D008253:Macaca mulatta / Q000502:physiology; D008297:Male; D009997:Osmotic Pressure; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012662:Semen Preservation / Q000009:adverse effects / Q000662:veterinary; D013094:Spermatozoa / Q000378:metabolism / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
D017382:Reactive Oxygen Species; D013481:Superoxides; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase