[Endocrine function of the heart: structuro-functional aspects]. / Endokrinnaia funktsiia serdtsa: strukturno-funktsiona'lnye aspekty.

Modern notions, accumulated during the period of investigation of before poorly studied endocrine++ function of the heart are presented. History of the problem, structural and functional aspects on argumentation of the cardiac endocrine function, place and role of physiologically active cardiac peptides in regulation of liquor and electrolytic homeostasis are followed, as well as interactions of the cardiac endocrine apparatus with the hormonal system of the organism. The authors' experience on the investigation connected with the problem is also demonstrated.

[Morphophysiological organization of the sinoatrial node of the rat heart]. / Morfofiziologicheskaia organizatsiia sinusovogo uzla serdtsa krys.

A combined morphophysiologic study of the rat heart sinus node pacemaker cells showed this conductive formation to comprise true and latent pacemakers. The latent pacemaker cell population is heterogeneous in terms of electric activity as well as morphology. The electrophysiologic and morphologic characteristics of latent pacemaker cells undergo a smooth change from centre to periphery of the sinus node. No criteria could be identified for accurate correlation of morphologic and electrophysiologic characteristics of sinus node pacemaker cells, not even by intracellular labelling of cardiomyocytes that belonged to definite electric activity types. The differences between these cells are assumed to be largely related to specific membrane structures, such as ion channels and receptors.

[Morphologic indices of the rat heart after colchicine application to the vagus nerve]. / Morfologicheskie pokazateli serdtsa krysy v usloviiakh applikatsii kolkhitsina na bluzhdaiushchii nerv.

By means of the light optic and electron microscopic methods atrial ganglia, myocytes, vessels of the right cardiac chambers have been studied in rats 2 days--3 weeks after application of 100 mcg of colchicine on the right nervus vagus. Certain changes of the neural fibers have been described at the area of the application. In the myocardium the microcirculatory bed, focal edema and hypoxic alterations of the myocyte ultrastructure have been revealed. In the ventrical ganglia destruction of some terminals of the preganglionar fibers, chromatolysis and vacuolization of single neurocytes, as well as intraganglionar granule-containing cells have been found. The changes described take place for 7 days and they nearly completely disappear in 10 days. A suggestion is made that some phenomena, in particular, destruction of the preganglionar fibers and changes of the cardiac microcirculatory bed are connected with certain disturbances of the quick transport of substances in the nervus vagus fibers.

[Action of noradrenaline and dopamine on the pacemaker cells of the normal rat sinus node and in pharmacological sympathectomy]. / Deistvie noradrenalina i dofamina na kletki-voditeli ritma sinusnogo uzla serdtsa krys--v norme i v usloviiakh farmakologicheskoi desimpatizatsii.

The authors studied the action of the physiological concentrations of catecholamines on the major parameters of the action potentials of the true pacemakers, using a graphic analysis of their electric activity at the intracellular microelectrode lead. Desympathization was carried out with the help of daily intraperitoneal injections of guanethidine solution for six weeks. Noradrenaline and dopamine have a similar effect on the electrogenesis of the pacemakers by decreasing a relative threshold of auto-stimulation and decreasing the steepness of the potential growth in phase 4 on the curve of the action potential. Pharmacological desympathization leads to the development of hyper-reactivity of the true pacemakers to noradrenaline and dopamine and triggers off changes in the regulation of the electric activity of these cells by catecholamines.

[Ultrastructure of the pacemaker cells of the sinoatrial node in rats]. / Ul'trastruktura kletok-voditelei ritma sinusno-predserdnogo uzla u krys.

Ultrastructure of the cells generating the action potential, specific for the pacemaker of the sinuous-auricular node has been studied. The cells are labelled with lanthanum chloride by means of the registrating microelectrode. Two types of pacemakers are revealed. The cells of one type contain specific auricular granules, while those of the other type do not contain them. The pacemaker-cells of the sinuous-auricular node have some peculiarities in the structure of the contractile apparatus, mitochondria, Golgi complex, intercellular contacts owing to which their morphological identification is possible.

Morphometric examination of the sinoatrial region of the heart.

A quantitative electron-microscopic examination was performed of the tissue structure of the working and conducting myocardium of the sinoatrial region of rat heart. The volume fractions of intracellular components of specialized myocytes of the sinus node and of internodal conduction tracts, as well as of working cardiomyocytes of the right atrium were measured. The study presents a characteristic of cell dimensions of myocytes of the given region. Principles of a universal classification of cardiomyocytes making it possible to automatically allot heart cells to individual structurally different classes are discussed.

[Autoradiographic study of protein synthesis in the muscle and interstitial elements of the myocardium during development of compensatory heart hyperfunction]. / Avtoradiograficheskoe issledovanie belkovogo sinteza myshechnykh i interstitsial'nykh élementov miokarda v protsesse formirovaniia kompensatornoi giperfunktsii serdtsa.

In the emergency stage of heart compensatory hypertrophy induced by constriction of the abdominal aorta, quantitative autoradiographic localization of newly synthesized proteins and RNA was studied in the left ventricular myocardium of adult rats 1 and 3 hours after the injection of 3H-leucine and 3H-uridine, respectively. The animals were sacrificed 1, 5 and 10 days after the operation. The amount of the autoradiographic grains was measured separately for muscle and interstitial components of the myocardium. A substantial increase in protein synthesis as regards muscle and non-muscle components was recorded only on day 10 of the experiment. At the same time incorporation of amino acids into protein of muscle and interstitial components was found to be higher by 42 and 60%, respectively. The labeling of RNA in muscle cells was similar to that of protein. In interstitial cells, the content of labeled RNA consistently rose throughout the whole experiment.

[Morphology of 2 cardiomyocyte populations in the papillary muscles of the rat heart]. / K voprosu o morfologii dvukh populiatsii kardiomiotsitov v sosochkovykh myshtsakh serdtsa u krysy.

A light optic and quantitative electron microscope investigation has been performed in order to study papillary muscles in the rat heart. Certain quantitative differences have been revealed in the structure of the conducting and working myocardium. Innervation of the papillary muscles has been characterized. A new type of the conducting cardiomyocytes (IV) has been revealed which had not occurred in the composition of the sinuatrial and atrioventricular ganglia of the atrioventricular (His') bundle and its peduncles, their differences from other three types of the conducting cells revealed before are described. The data obtained are compared to morphological characteristics of the papillary cardiac muscles in other mammalian species.

[Myocardial connective tissue component in the critical stage of compensatory cardiac hyperfunction]. / Soedinitel'notkannyi komponent miokarda v avariinoi stadii kompensatornoi giperfunktsii serdtsa.

The reaction of the connective tissue component of the rat left ventricular myocardium to hypertrophy induced by ventral aorta coarctation in the subdiaphragmatic part was studied by electron microscopy with the use of morphometric analysis. The animals were sacrificed 1, 5 and 10 days after the operation. It the heart of intact animals, the relative amount of the connective tissue was equal to 10.2%. Of this number, 2% were cellular elements, 0.2 and 8% were fibrous and amorphous parts of the intermediate tissue, respectively. In the emergency stage of hypertrophy there was an augmentation of the total amount of the connective tissue, the ratio of its diverse components varied with time. Moreover, an activation of the synthetic processes was recorded in the cells of the fibroblastic type.

[Morphology of the principal divisions of heart conducting system of rats]. / Morfologiia osnovnykh otdelov provodiashchei sistemy serdtsa krysy.

Light optic and electron microscopic investigation of the sinuauricular node node (spu), atrioventricular node (pzhu) and bundle of His (pzhp) has been carried out in 23 hearts of intact non-inbred male rats. Original techniques of oriented embedding of elements of the conductive system for their electron microscopic identification have been suggested. A morphological classification of specialized cardiac myocytes has been worked out basing on differences in their form and size, number of myofibrils and degree of their regulation. On its base three type of specialized myofibrils have been revealed in the conductive system. Topography of these cells has been described within spu, pzhu and pzhp. The suggested ultrastructural classification of specialized cardiac myocytes is compared with the data obtained for the cardiac conductive system in other types of mammals.

[Electron microscopic study of the innervation of the heart conduction system in rats]. / Elektronno-mikroskopicheskoe issledovanie innervatsii provodiashchei sistemy serdtsa krysy.

A systemic quantitative electron microscopic analysis on innervation of the sinus node, the atrioventricular node, the bundle of His and its pedicles within the interventricular septum has been performed in intact hearts of mature rats. The data have been obtained on the size of nonmyelinated and myelinated nerve fibres, efferent and afferent terminals within different parts of the cardiac conductive system, their interconnection with specialized cardiomyocytes have been described. Application of certain methods for electron microscopic investigation on the innervation of mammalian cardiac conductive system has been discussed.

[Morphologic analysis of the specialized cardiomyocytes of the heart conduction system of vagotomized rats]. / Morfologicheskii analiz spetsializirovannykh kardiomiotsitov provodiashchei sistemy vagotomirovannogo serdtsa krysy.

The specialized conduction system of the rat heart was studied by light and electron microscopy at various periods following vagotomy. The dynamics of tissue and cellular alterations is described. Variegation of the cellular reactions at all the postdenervation periods for all the conduction system parts and for all types o specialized cardiomyocytes was revealed.

[Ultrastructure of the cardiomyocytes of the pedicles of the bundle of His in the rat heart]. / Ul'trastruktura kardiomiotsitov nozhek puchka Gisa v serdtse krysy.

Light optic and electron microscopic investigation on composition and geometry of His' bundle branching in the upper part of the intraventricular septum was made. Branching of both peduncles of the atrioventricular (AV) bundle were demonstrated to be represented by a single cell type, its ultrastructure was described. Possibility to apply different ultrastructural criteria in order to determine this (III) type of cells in the conducting system of the heart was discussed.