Histoenzymological Characteristics of the Contractile Myocardium in Experimental Stenosis of the Aorta

Abstract

Contractile cardiomyocyte metabolism was studied by histochemical methods in experimental stenosis of the aorta complicated and not by heart failure. Acceleration of the citric acid cycle, more intense oxidation of free fatty acids and their metabolites, glycolysis intensifi cation, and higher activity of shuttle mechanisms were found in the contractile cardiomyocytes in stenosis of the aorta not complicated by heart failure. The presence of these metabolic shifts in the myocardium of all studied compartments suggests their association with not only more intense heart work, but also with the effects of total systems neurohumoral factors. Comparative study of myocardial metabolism in two variants of experimental stenosis of the aorta has revealed changes prognostically unfavorable for the development of heart failure. These changes include exhaustion of glycogen reserve, glycolysis inhibition, and metabolism shift towards biosynthetic processes. These data indicate an important role of glycolysis in support of myocardial contractile function during the acute phase of pressure overloading of the heart. Address for correspondence: mtver@rsmu.ru. M. S. TverskayaThe contractile function of the myocardium and its metabolism are closely related. Metabolic changes in the contractile cardiomyocytes underlie heart adaptation to increase of hemodynamic loading and to heart failure [5,6]. Experimental stenosis of the aorta traditionally serves as the basic model for studies of the mechanisms of compensatory hyperfunction of the heart. Studies of the myocardium of not only hemodynamically overloaded left ventricle (LV), but also of right ventricle (RV) and interventricular septum (IVS) are an important methodological approach to these studies, due to which it is possible to differentiate the changes emerging as a result of hyperfunction from changes caused by total systems factors (common for all compartments of the heart). Comparative study of these processes under conditions of experimental stenosis of the aorta complicated or not by heart failure is particularly interesting, as it demonstrates the prognostically unfavorable changes associated with the development of heart failure.We studied by histochemical methods the metabolism of contractile cardiomyocytes in LV, RV, and IVS in experimental stenosis of the aorta complicated and not by heart failure.