[The influence of physical activity on concetration of acute-phase proteins and the parameters of the oxidative stress in gallopers. [Doctoral dissertation]] | Uticaj fizičkog opterećenja na koncentraciju proteina akutne faze i parametre oksidativnog stresa kod trkačkih konja. Doktorska disertacija

Physical activity of various intensity and lasting influences the biochemical and metabolic processes in living organisms. The goal of this research was to investigate the influence of short-lasting intense physical activity of gallopers which had ran 2,400m and forty-kilometer endurance riding on acute-phase proteins (APP) and the parameters of the oxidative stress. Blood plasma, serum and washed erythrocytes of horses were examined for the concentrations of most important APPs (serum amyloid A, haptoglobin, ceruloplasmin and albumins), concentration and electrophoretic diversity of total proteins, lipid status and electrophoretic diversity of lipoproteins. The following parameters of oxidative stress were evaluated: the degree of lipid peroxidation (via the concentration of erythrocyte malonaldehyde), the activity of erythrocyte antioxidative enzymes (superoxide dismutase and catalase), the concentration of nitrites, isoenzyme diversity of lactate dehydrogenase, the activity of metalloproteinases MM-2 and MM-9 and the changes in biomacromolecules, especially the modificators of proteins (via the numbers of carbonyl and free thiol groups) and the modificators of glycoproteins and lipoproteins. The result suggest that physical activity of various degree impact the individuals examined by increasing both the synthesis and concentrations of APP, changing the lipid status, as well as boosting the production of free oxygen radicals (ROS) and reactive nitrogen species (RNS), leading to oxidative and carbonyl stress and severe damage of cell membranes caused by lipid peroxidation. The activities of extracellular metalloproteinases are enhanced, especially that of MM-9. The modification of biomacromolecules under the influence of ROS and RNS was also observed, especially expressed on proteins, accompanied by changes in their electrophoretic diversity (both in native proteins and glycoproteins and lipoproteins). In conclusion, it seems that both low-level (forty-kilometer endurance riding) and high-level physical activity (gallop race) have influence on APP concentrations and lipid status in horses and may lead to oxidative and carbonyl stress.