[Effect of altitude hypoxia on ultrastructure of the left ventricle of rabbit heart and the response of the myocardium to acute verapamil administration at different altitudes]. / Vliianie gornoi gipoksii na sostoianie ul'trastruktury levogo zheludochka serdtsa krolikov i reaktsiia miokarda na ostroe vvedenie verapamila na razlichnykh vysotakh.

It was shown in experiments on intact male rabbits that moderate-altitude hypoxia causes over-stress of the cardiomyocyte energy-producing apparatus in unadapted animals. Acute infusion of verapamil leads to a high mortality rate among these animals, whereas among aborigines of moderate and low altitudes as well as among animals living in the planes mortality in acute verapamil infusion does not exceed 30%.

[Types of mitochondria destruction in the cardiac myocyte (from the data of scanning electron microscopy)]. / Tipy destruktsii mitokhondrii v serdechnom miotsite (po dannym rastrovoi élektronnoi mikroskopii).

Scanning electron microscopy has revealed three types of myocardial mitochondria degradation in intact rabbit heart: desquamation of the external membrane, mitochondria swelling with their following destruction, mini-focal ulceration of mitochondrial external membranes. There was a clear-cut daily and seasonal dynamics of the three types of degradation. Mitochondria degradation was much more pronounced in the fibrillating than in intact heart.

[Effect of geomagnetic storms on the state of heart mitochondria and their role in providing energy for myocardial contraction]. / Vliianie geomagnitnoi buri na sostoianie mitokhondrii miokarda i ikh rol' v énergeticheskom obespechenii sokratitel'noi funktsii serdtsa.

The experiments on intact rabbits have shown that geomagnetic storm breaks the relationship between the size of myocardial mitochondria and the degree of cardiac contractility, causes swelling and further destruction of mitochondria. Geomagnetic storm leads to a decline in the left ventricular contractility. The development of geomagnetic storm is associated with a significant strong positive correlation between the size of mitochondria and the blood level of free fatty acids.

[Changes in the myocardial mitochondria in the dynamics of ventricular fibrillation (based on scanning electron microscopic data)]. / Izmeneniia mitokhondrii miokarda v dinamike fibrilliatsii zheludochkov serdtsa (po dannym rastrovoi élektronnoi mikroskopii).

Left ventricle of the rabbit heart was studied in the scanning electron microscope 1,2 and 5 minutes after the heart fibrillation induced by an impulse electrical current. It is found that as long as the fibrillation developed the degree of the structural heterogeneity of the heart muscle increased, the swelling of mitochondria and rough damage of their membranes occurred.

[Reproductive characteristics of the mitochondria in the cardiac myocyte detected by scanning electron microscopy]. / Osobennosti reproduktsii mitokhondrii serdechnogo miotsita, obnaruzhivaemye s pomoshch'iu rastrovoi élektronnoi mikroskopii.

Scanning electron microscopy of the left ventricle myocardium of intact rabbit revealed that the mitochondria of cardiac myocytes are formed by division, budding, synthesis de novo from the hyaloplasm, and by "lacing" from channels of the sarcoplasmic reticulum.

[Change in the mitochondria of the left heart ventricle in the intact rabbit during the course of the day (based on scanning electron microscopic data)]. / Izmenenie mitokhondrii levogo zheludochka serdtsa intaktnogo krolika na protiazhenii sutok (po dannym rastrovoi élektronnoi mikroskopii).

The myocardium of the left ventricle of intact rabbit was investigated by scanning electron microscopy during 24 hours, namely at 0, 6 a.m., noon and 6 p.m. It was discovered that the mitochondria reach the maximal volume at 6 p.m. and the minimal at 6 a.m. The qualitative differences in the mitochondria at different periods of the day are described. A correlation was established between the swelling of the mitochondria and some indices of heart function.

[Effect of large heparin doses on the contractile function, structure and lipid metabolic indices of the myocardium in intact rabbits]. / Vliianie bol'shikh doz geparina na sokratitel'nuiu funktsiiu, strukturu i nekotorye pokazateli lipidnogo obmena miokarda intaktnykh krolikov.

The effect of large doses (700 U/kg daily for 6 days) of heparin on the heart contractile function, myocardial morphology, content of free fatty acids in the blood, and the activity of tri- and monoglycerin lipase in blood plasma and heart tissue of intact rabbits was studied 24, 72 hours and 6 days after the beginning of heparin administration. It was established that the activity of lipolytic enzymes intensified, the concentration of free fatty acids in blood plasma grows, and the myocardial contractility increases after heparin administration. The phase structure of the cardiac cycle is simultaneously disturbed slightly. It is concluded that the intensification of lipolysis plays a role in increasing the myocardial contractility.

[Morphofunctional features of the left ventricle of rabbits with experimental alcoholic cardiomyopathy]. / Morfofunktsional'nye osobennosti levogo zheludochka serdtsa krolikov pri éksperimental'noi alkogol'noi kardiomiopatii.

In chronic alcoholic poisoning the rabbits demonstrate an abrupt decrease in heart left ventricular contractility and a significant noticeable prolongation of the phases of isometric effort and isometric relaxation. The morphologic study of the heart showed marked myocardial hypertrophy and enhanced intramyocardial lypolysis leading to accumulation of acid lipids by the cardiac muscle. It seems likely that these lipids requiring additional oxygen amounts for utilization give rise to relative hypoxia in the myocardium. In conjunction with diastolic inadequacy this can lead to attenuation of the heart contractility and to compensatory development of myocardial hypertrophy.

[Lysosome activity in mice during rejection of a heterotopic heart implant]. / Izmenenie aktivnosti lizosom pri ottorzhenii geterotopicheskogo implantata serdtsa u myshei.

Allotransplantation of the heart from newborn mice C57B1/6 into the pinna of adult CBA mice on the 3rd day after operation led to increased acid phosphatase activity and activation of the Golgi apparatus. Numerous lysosomes whose membrane became disrupted on the 7th-9th day from the time of implantation appeared later. At the same time histochemical study demonstrated local loss of acid phosphatase activity and a diffuse staining (brown) of the cytoplasm. No destruction of the lysosome membranes or release of the enzymes into the cytoplasm occurred in case of heart isografts (CBA-GBA).

[Several features of cardiac lipid metabolism under conditions of diphteritic intoxication]. / O nekotorykh osobennostiakh metabolizma lipidov serdtsa v usloviiakh difterinoi intoksikatsii

Basing on the collation of data of histochemical and electron-microscopic investigations of the myocardium of rabbits under conditions of diphtherial intoxication and in blocade of the lipolysis processes in the intact and damaged heart, the authors singled out three ways of utilization of lipids by the cardiac muscle. The first way is associated with adsorption of fatty acids from the circulating blood. This way depends on catecholamines and is blocked with nicotinic acid. The second way is determined by splitting of myocardial triacylglycerols. It does not depend on concentrations of catecholamines and can be blocked only following prolonged exposure to nicotinic acid. The third way is associated with intensity of functioning of mitochondria; destruction of the latter brings about liberation of membrane phospholipids which later are transformed into nonesterified fatty acids. This way does not depend on catecholamines and can be inhibited by acid lipids accumulating in the myocardium as a result of impairment of utilization of these lipids.

[Effect of large doses of nicotinic acid on certain metabolic processes and contractile function of an intact heart]. / Vliianie bol'shikh doz nikotinovoi kisloty na nekotorye obmennye protsessy i sokratitel'nuiu funktsiiu intaktnogo serdtsa

Peroral administration of nicotinic acid to rabbits in amounts of 500 mg, twice a day for 7 days was attended by a reduced contractility of the myocardium, an increased content of catecholamines in the heart and deranged lipids metabolism in the heart muscle. It is assumed that the contractility of the heart is largely determined by the state of the lipids metabolism and their utilization in the generation of energy.