Reduction of boar semen sperm motility by oxidation on membrane lipid bilayer

Oxidative stress has been reported as one of the most important factors contributing to poor quality semen. The main targets of radicals are the lipids contained in the cellular membrane. Reactive species cause membrane lipid peroxidation, which then modifies the membrane permeability and fluidity. This investigation was conducted to study the physical properties of the sperm membrane of boars, total antioxidative activity in relation to sperm motility. The study was performed on two boar breeds: German Landrace (N = 14) and Pietrain (N = 9). Samples of semen (sperm rich fraction) were taken using a single phantom. Semen volume, sperm concentration and total sperm count were determined and morphology (Papanicolaou and eosin-nigrosine staining method) were analyzed. The antioxidant capacity of semen was examined using galvinoxyl free radical and recorded by the electron spin resonance (ESR). The sperm membrane fluidity has been studied by ESR spin-trapping technique and order parameter, as a direct measure of motility, has been determined. Semen volume and total sperm count of Pietrain boars were significantly lower compared with that in German Landrace. Obtained result show that breed Pietren has statistically significant better motility and total antioxidative activity than German landras. These results demonstrate that decreased activity of antioxidants in the seminal plasma and in spermatozoa are correlated with reduction of sperm motility. It was also shown that ESR spectroscopy is useful technique for investigation of changes in membrane fluidity and total antioxidative activity.