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Purpose of the study. Studying the features of microcirculation, functional state and anatomy of the heart using the “Holiday Heart” syndrome model in rats we developed.Materials and methods. Experiments were carried out on white outbred male rats. The “Holiday Heart” syndrome was modeled as follows: animals received a 10 % aqueous ethanol solution as the only source of fluid for the first 10 days, then tap water for 10 days, and again a 10 % aqueous ethanol solution for the next 10 days. One day after the end of the repeated intake of alcohol, the animals were taken into the experiment. Animals that received free access to tap water served as control. Some rats in the experimental group (n = 10) had an echocardiogram recorded before the start of the experiment, and on the 31st day of the experiment, after which the level of microcirculation of blood and lymph in the brain and heart was measured using laser Doppler flowmetry. In the remaining animals (n = 10), microcirculation of blood and lymph in the brain and heart was assessed on the 3rd day of alcohol deprivation.Results. Analysis of the obtained data showed that in the conditions of the “Holiday Heart” syndrome model, significant changes occur in the anatomy, functional activity and geometry of the heart: there is a significant thinning of the anterior wall of the left ventricle heart (LV), an increase in systolic and diastolic volumes and sizes of the LV and a significant (p = 0.0018) decrease in its inotropic function. These changes occur against the background of a significant (p = 0.0081) decrease in the level of blood microcirculation in the myocardium, however, on the 3rd day of deprivation, blood flow in the microvessels of the heart increases statistically significantly (p = 0.0285).Conclusion. In model experiments reproducing the “Holiday Heart” syndrome, it was shown for the first time that ethanol causes significant changes in the microcirculation, anatomy, functional activity and geometry of the left ventricle of the heart, which, apparently, can play a key role in the formation of myocardial electrical instability pathognomonic for this syndrome.

Purpose of the study. Studying the blood microcirculation characteristics in the brain and heart of rats with ACM.Materials and methods. The study was carried out on white outbred male rats. The animals were randomized into 2 groups: 1st (n = 7) — control (intact) rats that received a normal diet and free access to water; 2nd (n = 6) — animals that received a normal diet and a 10 % ethanol solution as the only source of liquid. After 24 weeks of alcoholization in animals, the size and inotropic function of the heart were assessed using echocardiography. The next day, in anesthetized rats (urethane 1300 mg/kg i.p.), blood microcirculation in the heart and brain was recorded using a computerized laser analyzer “LAZMA-D” (manufactured by NPP “Lazma”, Russia) using the LDF 3.0.2.396 program. Using spectral wavelet analysis, the amplitudes of endothelial, neurogenic, myogenic, pulse and respiratory oscillations of microblood flow and the shunting index were determined.Results. According to echocardiography data, in rats that consumed a 10 % ethanol solution for 24 weeks, ACM is formed, which is accompanied by a decrease in blood microcirculation in the brain and myocardium. Thus, if in control animals the indicator of blood microcirculation in the myocardium was 36.60±2.19 perf. u., then in rats with ACM it was equal to 26.88±1.50 perf. u. units (p = 0.004). In the myocardium of rats with ACM, compared with control animals, the amplitude of both active and passive oscillations of microblood flow was significantly greater.Conclusion. In rats with ACM, the level of blood microcirculation in the heart muscle is significantly reduced, which, according to the results of spectral wavelet analysis, is prognostically unfavorable.

Background. Earlier, on the translational model of alcoholic cardiomyopathy (ACMP) developed by us in outbred white rats, which reproduces the main clinical diagnostic signs of this disease, it was shown that in rats of both sexes under conditions of constant 24/7 alcoholization for 24 weeks, AСMP is formed.This study purpose is a comparative assessment of the features of the ACM formation in male and female rats depending on the level of ethanol consumption in model experiments simulating "domestic drunkenness" with periodic alcoholization 24/2 for 24 weeks.Materials and methods. Experiments were performed on outbred white rats randomized into 4 groups: group 1 — control male rats (n=18), group 2 — control female rats (n = 18), group 3 — alcoholized male rats (n = 39) and group 4 — alcoholized female rats (n = 19). Control animals received a normal diet and free access to water. Animals of the 3rd and 4th groups weekly, for 24 weeks, from Friday 22.00 to Monday 8.00, received a 10 % ethanol solution as the only source of liquid with unlimited access to standard food, and the usual diet on the remaining days.Results. In animals of both sexes, after 24 weeks from the consumption start of the ethanol solution, ACM is formed, as evidenced by an increase in the end-systolic and end-diastolic sizes of the left ventricle of the heart (p = 0.0001) and a decrease in its ejection fraction (p = 0.0001), while the degree of pathological myocardial remodeling is more pronounced in females. According to cluster analysis, by the consumption of ethanol (CET), animals of both sexes are divided into 3 subgroups: low, medium and high CET, however, in males, the subgroup with an average CET prevails — 56 %, and in females with a high CET — 47 % (p = 0.0286), the low CET subgroup is minimal (16 %). At the same time, if in males in all subgroups, starting from the 8th week of alcoholization, CET dynamically decreases, then how in females in subgroups with medium and high CET, starting from the 16th week, it increases. It was found that the degree of left ventricular remodeling in females with high and moderate CET was almost 2 times higher than in males (p < 0.05).Conclusion. In model experiments imitating “domestic drunkenness”, it was shown that in females the intensity of the left ventricle heart remodeling is significantly higher than in males, which, apparently, is determined by the identified gender-dependent multidirectional trends in the formation of alcoholic behavior characterized by dynamic growth. consumption of ethanol in female rats as the duration of alcoholization increases.

Purpose of the study. Comparative evaluation of echocardiographic and morphometric dimensions of the rat heart left ventricle. Materials and methods. The study included 10 outbred male rats weighing 160–180 g. The size of the heart left ventricle was assessed using echocardiography and morphometry. The measurements were carried out according to standard protocols. To perform morphometric measurements, hearts were stopped in systole with a lethal dose (1.0 mg/kg) of 0.025 % strophanthin K solution, and in diastole, by immersing the hearts in a chilled physiological solution (calcium-free medium). Results. It was shown that the systolic size of the left ventricle of the heart according to echocardiography is 1.79Ѓ}0.10 mm, and morphometry 1.64Ѓ}0.09 mm (p = 0,302); diastolic size of the left ventricle, respectively, 3.42Ѓ}0.16 mm and 3.66Ѓ}0.17 mm (р = 0,318). The detected discrepancies do not exceed 10 % and, apparently, are due to the fact that the physiological dimensions of the heart left ventricle are measured by a non-invasive echocardiographic method, and for morphometric measurements of the dimensions in the systole, the heart was stopped by injection of strophanthin K, which entails an overload of heart cells with Ca2+ ions and as a result, contracture of cardiomyocytes; post-mortem cardiac arrest in diastole, in a calcium-free environment, is accompanied by a loss of cardiac muscle tone and, therefore, dilatation of the left ventricle will naturally be greater than physiological. Conclusion. Noninvasive echocardiographic measurement of the size of the heart left ventricle fully reflects the actual size of the left ventricle of the rat heart (the difference does not exceed 10 %), i. e. echocardiographic measurements are valid.

The aim of the present study is a comparative assessment of the echocardiographic characteristics in female and male mongrel rats. In experiments on anesthetized rats (ketamine 100 mg / kg, iv), it was shown that in female rats, the size and volume of the left ventricle are smaller than in males, but compared with males, their left ventricular ejection fraction, which characterizes its inotropic function, is statistically significantly higher.

The exprimants based on our translational model of chronic post-infarction heart failure within the use of echocardiography showed that in animals after 90 days after the reproduction of the myocardial infarction compared to the sham operated animals there is a significant increase in the endsystolic and end-diastolic sizes of the left ventricle (respectively, from 2.49 ± 0.09 to 3.91 ± 0.17 mm, p = 0.0002, and from 3.56 ± 0.12 to 5.20 ± 0.19 mm, p = 0.0002) and the decrease of its inotropic function that indicates a simulated pathology. 5 days after the echocardiographic study, the animals' exercise tolerance was assessed in the treadmill-run to failure test. It is proved in rats that 90 days after the coronary artery litigation the tolerance of physical activity decreases sharply – the value of the distance covered by them is 109.21 ± 11.61 m, which is 2.5 times less than the distance covered by sham operated animals (p = 0.003) and 5.3 times less than the distance covered by intact rats (p = 0.0001), – which is pathognomonic for chronic heart failure and complements the data of previously conducted morpho-histological, biochemical and molecular studies, indicating that the present model reproduces the main clinical and diagnostic signs of the simulated pathology.

Resume. The purpose of this investigation is to study the adequacy of the echocardiography method in small laboratory animals for performing acute pharmacological tests. In experiments on white mongrel male rats, a nonselective ß-adrenoreceptor agonist isoproterenol (20 μg /kg, i.v.) reduces the end-systolic and end-diastolic dimensions and volumes of the heart left ventricle, measured by echocardiography, and increases the shortening and ejection fractions, i.e. has a positive inotropic effect. Cardioselective ß1-adrenoblocker metoprolol (1 mg / kg, i.v.), on the contrary, increases the left ventricle sizes and reduces the shortening and ejection fractions, i.e. has a negative inotropic effect. Thus, the method of echocardiography in small laboratory animals can be used to conduct acute pharmacological tests.

Resume. Relevance. One of the actual problems facing modern medical science is the study of mechanisms and the search for effective ways to activate tissue neovascularization. A possible approach to the decision of this problem is the use of TrkA receptor agonists to activate angiogenesis and, as a consequence, improve the vascularization of ischemic tissues. The aim of this investigation was to study the angiogenic and antiischemic activity of the TrkA receptor agonist the nerve growth factor 4th loop dipeptide mimetic the GK-2 compound. Methods. Experiments were performed on models of hind limb ischemia and myocardial infarction in rats. The compound GK-2 (1 mg/kg) was administered intraperitoneally for 14 days. Effects were evaluated using light microscopy and two-dimensional echocardiography. Results. In the model of the hindlimb ischemia in rats, it was shown that GK-2 (1 mg/kg, i.p.) significantly enhances the vascularization of the ischemic sural muscle. The vascularization index of ischemic tissue in animals treated with GK-2 was almost 2 times higher than in control - 27794 (25218 t 35941) and 14725 (9030 t 19630), respectively (p < 0.001). According to light microscopy, the studied compound reduces the intensity of tissue damage. Under conditions of experimental myocardial infarction, the GK-2 compound reduces the pathological remodeling intensity of the heart left ventricle. Conclusion. It can be assumed that the antiischemic effect of GK-2 is associated with increased vascularization of the affected tissue, i.e. with the stimulation of angiogenesis.

In the previousLy deveLoped transLation modeL of aLcohoLic cardiomyopathy in white nonLinear rats was studied the cardioprotective effects of trimetazidine and fabomotizoLe hydrochLoride that were injected daiLy during the 25th - 28th weeks of continued consumption of 10% ethanoL It is shown that trimetazidine (30 mg/kg/day i.p.) and fabomotizoLe hydrochLoride (15 mg/kg / day i.p/) in the above conditions, significantLy reduced the remodeLing of the Left and right ventricLes of the heart and increased the heart contractiLe function.