Біохімічні маркери міокардіодистрофії в спортивних коней за фізичного навантаження

As a result of diseases of the heart muscle, substances released from damaged cardiomyocytes, in particular creatinе kinase (CК), lactate dehydrogenase (LDH), myoglobin, cardiac-specific troponins T and I (TrT, TrI), which are called biochemical markers of myocardial damage, come into the blood. For the diagnosis of heart muscle damage, the definition of activity of cardiac isoenzymes is used. There are only isolated proven work devoted to the study of clinical and biochemical features of myocardial damage in horses, which prevents them from being widely used for diagnosis. The aim was to characterize the biochemical blood parameters, including activity of CK isoenzymes (CK-MB), and lactate dehydrogenase (α-Hydroxybutyrate dehydrogenase; HBDH) in sport horses for exercise. 50 horses were included into our research, used in the classic equestrian sport of Ukrainian warmblood horses (n=20), Hanoverian (n=15) and Westphalian (n=15) breeds horses. For all horses, a general analysis and biochemical blood indices were analyzed, characterizing the functional state of the organs (heart, liver, kidneys). Studies were carried out immediately before physical activities and immediately afterwards. The duration of medium intensity of regular training was 1 hour: walk – 5 minutes; rising trot – 10 minutes; walk – 5 minutes; sitting trot – 10 min; walk – 10 minutes; gallop with transition to a walk – 10 min; walk – 10 min. The metabolic reaction that occurs in sports horses during exercise is characterized by dehydration (hyperproteinemia), uremic syndrome (increased urea and creatinine concentrations), electrolyte imbalance (a decrease in sodium and potassium content). The main pathogenesis of myocardial dystrophy in sports horses is the discrepancy between costs and energy recovery in the functioning structures of the heart muscle due to excessive cardiac load and significant increase in energy expenditure, as well as a disturbance in the balance of the electrolytes. After physical activity in the blood serum of sports horses, the activity of AST and LDH increases, and a tendency to increase the activity of CK increases. A specific marker of myocardial damage in sports horses has been detected by CK-MB, since its activity is likely to increase in all experimental animal groups. A less specific marker of myocardial dystrophy in sports horses was the activity of HBDH, since the probable difference was only observed in the horses of the Westphalian breed. Investigation of the activity of AST, CK and CK-MB in horses can serve in the differential diagnosis of rhabdomyolysis syndrome and damage to the cells of the cardiac muscle, in particular for myocardial dystrophy. The obtained results can be used for diagnostics of heart diseases and serve in the future to study the pathogenesis of myocardial diseases in horses.