Antioxidant system parameters in boar spermatozoa of different morphology and motility

The proportion of different functional and structural spermatozoa subpopulations and the level of antioxidative systems in semen are associated with the ability for fertilization and storing semen. The aim of this study was to determine the antioxidant system parameters in boar spermatozoa fractions separated in an iodixanol solution. Semen samples of 27 boars, aged between 1.5 and 3 years, were collected in early autumn. Semen samples were centrifuged in a discontinuous iodixanol density gradient solution, and three semen fractions were obtained: spermatozoa with high motility, spermatozoa with very low motility, and abnormal spermatozoa. The values of total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in each semen fraction were determined spectrophotometrically. In the abnormal spermatozoa fraction, the values of the TAS and the GSH-Px were significantly lower (P<0.001), and the SOD was significantly higher than in fractions with high or very low spermatozoa motility (P<0.001 and P<0.05, respectively). The values of TAS, SOD and GSH-Px were significantly higher in spermatozoa with very low motility than in spermatozoa with high motility (P<0.001). Higher values of SOD obtained in abnormal spermatozoa and spermatozoa with very low motility were associated with impaired spermatozoa function, motility and morphology. Significantly lower values of TAS and GSH-Px (P<0.001) in abnormal spermatozoa indicate a decrease in antioxidative protection. The higher values of TAS and GSH-Px obtained in spermatozoa with very low motility than in spermatozoa with high motility could indicate enhanced antioxidative protection due to the increased production of the reactive oxygen species. Determination of antioxidant parameters in different semen fractions may help to explain the potential causes of infertility in boars.