[Evaluation of the effectiveness of the long-term use of obzidan in experimental myocardial infarct].

The authors performed a comprehensive study of the recovery processes in the myocardium after occlusion of the coronary artery in 126 white rats under the effect of a long-term treatment with propranolol (0.5 mg/kg). The drug reduced the size of necrosis by 2.6 times, significantly decreased the S-T segment rise on the ECG (up to 0.86 +/- 0.09 mV versus 1.85 +/- 0.15 mV, in untreated animals with myocardial infarction, P less than 0.001). The treated animals manifested the improvement of the morphologic status of the perinecrotic area and the myocardium of the posterior wall of the left ventricle. Cardiomyocytes preserved to a considerable degree the ultrastructure of the mitochondria, demonstrating an increase in DK and protein biosynthesis (up to 296.1%, P less than 0.001). At the same time the long-term treatment with propranolol led to an appreciable activation of intracellular reparative regeneration, acceleration of the renewal of organelles, thereby promoting a decrease in the hypertrophy of cardiomyocytes (by 22.1%, P less than 0.001) as compared with control. It is concluded that propranolol administered in a dose of 0.05 mg/kg favours rapid recovery of the functional structures of the myocardium.