THE UNIVERSALITY OF THE MANIFESTATION OF THE LAWS OF “DIVISION ↔ FUSION” AND “DIVISION ↔ CONNECTION” OF MATTER IN THE PROCESSES OF POSTNATAL DEVELOPMENT OF THE MITOCHONDRIAL AND MYOFIBRILLAR APPARATUS OF CARDIOMYOCYTES CARDIOMYOGENESIS IS ONE OF THE TOPIC

Abstract

Cardiomyogenesis is one of the topical directions of research into the complex general biological problem “Mechanisms of ontogenesis” of mammals and humans. Such studies are necessary to identify the causes of occurrence and develop scientifically based measures to prevent the development of embryonic and postembryonic heart defects of various etiologies. The functioning of cardiomyocytes of the parenchyma of the myocardium of the left ventricle of mammals and humans directly depends on the coordination of the interactions of the myofibrillar and mitochondrial apparatus. Many different physicochemical and biochemical processes that continuously occur in the organisms of living beings are carried out as a result of enzymatic processes of “crushing ↔ fusion” or “connection ↔ separation” of molecules, various substances, organelles that are part of cells and fabrics The peculiarities of the structure and functions of myofibrils and mitochondria, which form the contractile apparatus and the mitochondrial apparatus in the sarcoplasm of cardiomyocytes, are also carried out on the basis of the universality of the manifestation of the laws “division ↔ fusion” and “division ↔ connection”. Electron-microscopic and morphometric studies of agerelated changes in the ultrastructure of the mitochondrial and myofibrillar apparatus of cardiomyocytes of the left ventricle of the heart during the early postnatal ontogenesis of Wistar rats in the time interval from newborns to 45-day-old animals were carried out. The paper presents the kinetics graphs of the regularity of the sequence of processes of “division ↔ fusion”, “increase ↔ decrease” in the number of mitochondria and myofibrils, changes in the volume of these organelles in the composition of the mitochondrial and contractile apparatuses of binucleated cardiomyocytes of the myocardium of the left ventricle of the heart in the process of early postnatal ontogenesis of Wistar rats. It was established that in the period (n/y – 15) days intensive division of mitochondria (1МХ → 2МХ) and an increase in the number of these organelles in cardiomyocytes is determined. In the time interval (n/r – 45) days of postnatal maturation of cardiomyocytes, the number of myofibrils in the contractile apparatus of cardiomyocytes increases by ≈ 6.5 times from 12–13 pieces (n/r) to 80 pieces as a result of new formation of myofibrils and longitudinal splitting (separation) of existing myofibrils. A generalization is made regarding the relevance of studying the mechanisms of formation of mitochondria and myofibrils in cardiac muscle during the postnatal development of mammals and humans.