Antioxidant Enzyme Activity and mRNA Expression in the Reproductive Tissues of Male European Red Deer (Cervus elaphus elaphus)

The aim of this study was to analyze the influence of season (rut and non-rut) on the antioxidant status of selected reproductive tissues in male European red deer (<i>Cervus elaphus elaphus</i>). Tissue samples were collected post mortem from the testes and epididymides (caput, corpus, and cauda) of 24 animals. The activity of antioxidant enzymes (superoxide dismutase-SOD, glutathione peroxidase-GPx, and catalase-CAT) and the mRNA expression of SOD1, SOD2, SOD3, GPx4, GPx5, and CAT were examined. In addition, these proteins were identified by western blot. ANOVA revealed that season, type of tissue, and the interaction between these factors significantly (<i>p</i> ≤ 0.05) influenced the activity and mRNA expression of the analyzed enzymes. The activity of SOD and GPx peaked in the corpus epididymis in the rut season and in the caput epididymis in the non-rut season. Regardless of season, the relative abundances of GPx4, SOD1, SOD2, and SOD3 mRNA were highest in the testis, and GPx5 mRNA-in the caput epididymis. The activity of SOD and CAT was significantly higher during the non-rut season compared with the rut season, but only in the caput epididymis. This study demonstrated that the activity of antioxidant enzymes and the relative mRNA expression varies across tissues and seasons to provide the reproductive system of European red deer with the required antioxidant protection. Further research is needed to expand our understanding of the antioxidant defense system in the reproductive tract of European red deer.