The relative level of expression of antioxidant protection genes in calves with respiratory pathology

The aim of this study was to evaluate the relative expression levels of genes encoding key antioxidant enzymes, namely superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), in calves with respiratory disease. Respiratory diseases are also characterized by an imbalance between pro-oxidant and antioxidant mechanisms. Developing oxidative stress exacerbates the disease course and can be used as a target for therapeutic intervention. To achieve this goal, quantitative real-time polymerase chain reaction was used, with peripheral blood from sick and healthy calves serving as the research material. Healthy 3-month-old calves (n=10) and sick (n=10) animals of the same age with respiratory disease were selected for the experiment. The results showed a statistically significant increase in HIF-1α gene expression in the blood of calves with respiratory disease, indicating activation of the hypoxic response. SOD1 gene expression was also increased, which may indicate a compensatory reaction to oxidative stress. Furthermore, GPX1 gene expression was elevated in sick calves, which may indicate enhanced hydrogen peroxide detoxification in response to increased production of reactive oxygen species. At the same time, CAT gene expression did not show statistically significant differences between the groups. Increased expression of HIF-1α, SOD1, and GPX1 in the blood of sick calves reflects the activation of compensatory mechanisms in response to hypoxia and oxidative stress. The lack of significant changes in catalase expression may indicate that, in the early stages of the disease, this gene is not involved in compensatory processes to a sufficient extent, or its activation occurs at later stages.