Cumene hydroperoxide induced changes in oxidation-reduction potential in fresh and frozen seminal ejaculates

Oxidation-reduction potential (ORP) is a newer integrated measure of the balance between total oxidants (reactive oxygen speciesROS) and reductants (antioxidants) that reflects oxidative stress in a biological system. This study measures ORP and evaluates the effect of exogenous induction of oxidative stress by cumene hydroperoxide (CH) on ORP in fresh and frozen semen using the MiOXSYS Analyzer. Semen samples from healthy donors (n=20) were collected and evaluated for sperm parameters. All samples were then flash-frozen at -80 degrees C. Oxidative stress was induced by CH (5 and 50moles/ml). Static ORP (sORP(mV/10(6) sperm/ml) and capacity ORP (cORPC/10(6) sperm/ml) were measured in all samples before and after freezing. All values are reported as mean +/- SEM. Both 5 and 50moles/ml of CH resulted in a significant decline in per cent motility compared to control in pre-freeze semen samples. The increase in both pre-freeze and post-thaw semen samples for sORP was higher in the controls than with 50moles/ml of CH. The change from pre-freeze to post-thaw cORP was comparable. The system is a simple, sensitive and portable tool to measure the seminal ORP and its dynamic impact on sperm parameters in both fresh and frozen semen specimens.