Author
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Guthrie, Howard |
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Submitted to: Theriogenology
Publication Type: Abstract Only Publication Acceptance Date: 3/11/2007 Publication Date: 8/12/2007 Citation: Guthrie, H.D. 2007. Mitochondrial function and reactive oxygen species action in relation to boar motility. Theriogenology. VI International conference on boar semen preservation, Guelph, Ontario. August 12-15, 2007. Interpretive Summary: Technical Abstract: Flow cytometric assays were developed for reactive oxygen species (ROS) formation (ROS-induced oxidization of hydroethidine to ethidium), membrane lipid peroxidation (C11-BODIPY-581/591 oxidation), and mitochondrial transmembrane potential (MMP) (MMP-induced JC-1 aggregation, red fluorescence) in viable sperm during hypothermic liquid and frozen storage and to investigate the relationship between ROS, MMP, motility, and ATP production. During aerobic incubation of sperm at 37oC for 30 min ROS formation and lipid peroxidation affected less than 4% of sperm; the results did differ among the storage treatments. However, during incubation fresh, liquid stored and frozen-thawed sperm appeared to be equally susceptible to the activity ROS generators such as xanthine/xanthine oxidase, menadione, Fe2SO4/ascorbate, and hydrogen peroxide. Motility was depressed by 60 to 80%, but viability was not affected. Of the ROS generators tested, lipid peroxidation was specific for Fe2SO4/ascorbate; menadione and hydrogen peroxide had little or no effect. The ROS-induced oxidization of hydroethidine to ethidium was specific for menadione, xanthine/xanthine oxidase, and hydrogen peroxide; Fe2SO4/ascorbate had no effect. Surprisingly, while both menadione and H2O2 decreased motility, and menadione decreased MMP, neither decreased ATP production over a 60 min incubation period. Overall, the inhibitory affects of ROS on motility point to a mitochondrial independent mechanism for ROS induced motility inhibition. |
