Antioxidant protection and lipid peroxidation in testes and different parts of epididymis in boars.

The antioxidative ability of testes and epididymis to protect spermatozoa from detrimental effects of oxidation processes induced by excessive generation of reactive oxygen species has not been previously studied in detail in boar reproductive tissues. The aim of this study was to investigate differences in level of antioxidative protection, intensity of lipid peroxidation, and values of biochemical parameters in testes and different parts of epididymis in sexually mature boars. The study was performed on five Swedish landrace boars from the same litter aged 10 months kept under same ambient conditions. After slaughtering performed at the end of November; tissue samples of testes and the head, body and tail of epididymis were taken. The activity of glutathione peroxidase, glutathione reductase, superoxide dismutase, γ-glutamyltransferase, acid phosphatase, and lactate dehydrogenase, and concentrations of triacylglycerol, phospholipids, cholesterol, free fatty acids were determined in obtained supernatants from homogenized tissues spectrophotometrically; the concentration of malondialdehyde was determined by high-performance liquid chromatography. Significantly higher activities of glutathione peroxidase and glutathione reductase (P < 0.05) were found in testes compared with epididymis. In testes, a significantly higher activity of superoxide dismutase was found than in the head and tail of epididymis (P < 0.05). Malondialdehyde concentration in head of epididymis was significantly higher than in testes, or the body and tail of epididymis (P < 0.05). Simultaneously, malondialdehyde concentration in testes was significantly higher than in body and tail of epididymis (P < 0.05). In tail of epididymis, significantly higher activities of γ-glutamyltransferase, acid phosphatase, and lactate dehydrogenase were recorded than in testes. Significantly lower concentrations of triacylglycerol and free fatty acids were recorded in epididymis tail in comparison to epididymis head (P < 0.05). It could be concluded that high activities of antioxidative enzymes in testes of boars are essential for the appropriate protection of spermatozoa and cells of testes tissue against oxidative damages. The tissues of testes and epididymis head in boars were more susceptible to lipid peroxidation. Results of the present study indicated physiological importance of antioxidative enzymes in reproductive system in boars, and thus may serve for better understanding the mechanisms of male infertility.