The problems considered in the review are: mechanisms of formation of physiological and pathological endothelium phenotypes, endothelium involvment in hematovascular homeostasis, immune processes, inflammation, systemic inflammatory response. The reversibility of endothelial dysfunction, participation in hematovascular homeostasis, immune processes, inflammation, systemic inflammatory reaction, etc. are discussed. The validity conventional term «endotheliitis» for endothelial dysfunction in various diseases, including COVID-19 is analysed. We accept that endothelial dysfunction is a kind of pathological condition having both common features in many diseases and some features depending on the dominance of a particular phenotype (in sepsis, hypovolemic shock, etc.). The concept of endothelial dysfunction as the universal mechanism of endogenization and generalization of pathological process is proved. The development of methods affected on the phenotype and mechanisms of endothelial remodeling is a promising area of scientific research.

Introduction. Coronary heart disease (CHD) combined with type 2 diabetes mellitus (DM) requires enhanced secondary prevention.

The aim of the study was to evaluate the application possibilities of PCSK9 inhibitors in patients with coronary heart disease combined with type 2 diabetes.

Materials and methods. The study included 77 patients with coronary heart disease divided into 2 groups: the first group without type 2 diabetes (n=39) and the second group with concomitant type 2 diabetes (n=38). Before the experiment started all patients received a combination of the maximum tolerated dose of atorvastatin and ezetimibe and did not reach the target values of low-density lipoprotein cholesterol (LDL cholesterol), after that alirocumab was added to treatment. In all patients, for 12 months, the parameters of the lipid transport system, glycated hemoglobin and the dynamics of changes in the thickness of the intima-media complex of the carotid arteries were evaluated.

Results. After starting treatment with alirocumab, in the first group, LDL cholesterol targets reached 97.4 % (n=38), in the second group – 94.7 % (n=36). The LDL cholesterol level in the first group decreased from 2.27 [2.21; 2.35] to 1.15 [1.07; 1.28] mmol/l (by 49.1 %, p<0.001), in the second group from 2.32 [2.27; 2.36] to 1.17 [1.12; 1.19] mmol/l (by 49.6 %, p<0.001). A direct strong statistically significant correlation was revealed between the concentration of LDL cholesterol and other indicators of lipid metabolism.

Conclusion. The obtained results of PCSK9 inhibitors appliance in CHD patients with very high cardiovascular risk demonstrate a decrease in LDL cholesterol by 73.9 % in the group of CHD patients and by 74.2 % in the group of CHD patients in combination with type 2 diabetes. In the first group, the target concentrations of LDL cholesterol were reached by 97.4 % of patients, in the second group – 94.7 %. The achieved hypolipidemic effect was simultaneously combined with a decrease in the thickness of the intima-media complex in the group of patients with coronary artery disease: for the right common carotid artery by 7.8 %, for the left by 10.9 %; in patients with coronary heart disease with concomitant type 2 diabetes: for the right common carotid artery by 8.3 %, for the left by 8.1 %.

Introduction. The presence of endothelial dysfunction contributes to the progression of rheumatoid arthritis (RA) and the development of cardiovascular diseases. However, microcirculatory signs in the combination of RA with hypertension have not been studied enough.

Objective – to clarify the contribution of concomitant hypertension in the formation of microcirculatory disorders in patients with RA.

Materials and methods. The observational study involved 123 patients of both sexes from 18 to 72 years old (103 – the study group with verified RA, 23 – the control group, representing relatively healthy volunteers). Hypertension occurred in 55.3 % of patients. Laser Doppler flowmetry was performed to assess vasomotor function. Both the initial perfusion parameters were studied with the calculation of the amplitude-frequency spectrum, as well as an occlusive test and a test with acetylcholine iontophoresis. Initial perfusion parameters were studied with time– frequency analysis, an arterial occlusion test and an acetylcholine iontophoresis test were performed.

Results. Patients with concomitant hypertension against the background of RA had a more pronounced decrease in the amplitudes of the endothelial (p=0.036) and neurogenic (NC) (p=0.005) components of the spectrum, an increase in respiratory modulation (RM) (p=0.002), as well as a decrease in the reserve of capillary blood flow (p=0.010) and shortened time to perfusion half-restoration (p=0.042) in the occlusion test. However, there were no significant differences between the groups in terms of the acetylcholine iontophoresis test (p≥0.05). The relationship between the RM amplitude and cardiovascular risk (CVR) was established according to the SCORE (ρ=0.269; p=0.022), as well as with systolic (ρ=0.324; p=0.005) and diastolic (ρ=0.234; p=0.045) blood pressure was established. An assessment of the RM amplitude predicted the presence of concomitant hypertension with a sensitivity of 72.5 % and a specificity of 75 % (p=0.001).

Conclusion. The presence of concomitant hypertension against the background of RA was associated with more pronounced vasomotor dysfunction, as well as with the presence of venular hypertension (VH), which is the pathogenetic link of hypertension. At the same time, an increase in the amplitude of the RM, which reflects VH, allows it to be used as an early additional prognostic marker for the presence of concomitant hypertension and increased CVR in patients with RA.

Introduction. Physical activity is often used in rehabilitation to restore cognitive function after cerebral blood flow impairment and typological features like baseline cognitive ability may alter their effectiveness.

The aim was to evaluate the expression of nNOS and NeuN in the large hemisphere cortex in the cerebral hypoperfusion occurrence in rats having different scores in the Morris maze.

Materials and methods. Cerebral hypoperfusion was simulated by bilateral ligation of the common carotid arteries. Before surgery, Wistar rats were divided into equal subgroups with high (HCA) and low levels of cognitive ability (LCA) according to the results of Morris maze testing. Animals were removed from the experiment at 8, 21, 35, 60, and 90 days after surgery, a total of 184 rats, 24 formed the control group and 80 formed the cerebral hypoperfusion subgroup with 80 animals undergoing short-term swimming daily starting on day 7 of the experiment.

Results. We revealed the earlier changes in HCA animals (8th day of the experiment) induced by cerebral hypoperfusion accompanied by a more intense nNOS-positive neurons density reduction to 47 % of control values, the length of their processes, and an increase in pericarion area. In LCA the decrease of density was only 75 % of control values and pericarion area does not differ from control values. At later periods on the 60 and 90 days of the experiment LCA demonstrates the preservation of the neurons density and greater length of their processes (67 % of the control subgroup values).

Conclusion. HCA is a risk factor for damage of nNOS-positive neurons in cerebral hypoperfusion. Physical exercise more effectively decreases nNOS expression in animals with HCA, which may be one of the sanogenetic mechanisms of this factor.

Introduction. The widespread occurence of acute and chronic wounds in Russia and abroad determines the great relevance of improving the treatment technologies. The micro- and nanostructuring synthetic polymers (i. e., polylactide) open the new possibilities for creating biodegradable coatings having both scientigfic and applied interest.

The aim of present study was to investigate how microchamber polylactide biodegradable coatings affects microcirculatory changes in the area of a full-thickness experimental skin defect in white rats.

Materials and methods. The study was conducted on 40 white outbred rats, divided into 3 groups: control (CON, n=10), comparative (ESD) – 15 animals with a full-thickness experimental skin defect) and experimental (MPC) – 15 rats treated by a microchamber polylactide biodegradable coating on full-thickness experimental skin defect. Polylactide (polylactic acid) wound coatings in the form of microchambers arrays were fabricated based on a micron well pattern. On the 7th and 14th days of the experiment, in animals of the ESD and MPC groups, the area of the wound defect was measured and the skin microcirculation of the experimental wound edges was assessed by laser Doppler flowmetry (LDF).

Results. On the 7th and 14th days after the experimental wound defect formation in the rats interscapular region an increase of the wound edges skin perfusion by 26.9–27.8 % was observed accompanied by an active and passive mechanisms role redistribution in microcirculatory modulation with increase of perfusion fluctuation in the myogenic, respiratory and cardiac ranges. Using the a polylactide coating for the wound defect closure accelerated the process of epithelialization mainly on the first week of the experiment and reduced the severity of the perfusion increase in the edges of the experimental wound in the first week and completely recovered normal perfusion level in the second week of the experiment. Perfusion decrease of the experimental skin wound edges under the influence of polylactide coating in rats was accompanied by decrease in the amplitude of myogenic oscillations on the 7th day of the experiment by 20 %, and decrease the amplitude of respiratory oscillations on the 14th day by 19.7 % compared to ESD group.

Conclusion. The developed polylactide coatings reduce the severity of inflammatory changes in the microcirculation of the experimental wound edges. This redusing combined with the acceleration of wound epithelialization suggests that this type of dressing material is high biocompatible.

Introduction. The local decompression therapy (including local abdominal decompression) is known to contribute to the intensity of capillary blood flow and improve the functional state of the microvasculature. We have proposed a development could be used for intravital investigation of changes in microcirculation directly under local negative pressure conditions.

Purpose. Investigation of microcirculatory changes under the conditions of local negative pressure in the rat intestine and mesentery combined with pharmacological effects.

Materials and methods. Unit for vital microscopy under local negative pressure was used for this work. The specific of the unit is the ability of continuous record the field of view of the microscope before, during and after the decompression session. In the experiment there were used Wistar rat males weighing 300–450 g, distributed into 5 groups of 5 animals. The animals were divided into groups depending on the pharmacological impact: atropine, pilocarpinum, drotaverine and chloropyramine and the control group.

Results. It has been shown that dynamics of vascular constriction and dilatation after decompression session varies in response of certain agents suggested the involvement of certain receptor fields. The changing vessel number within the video recording frames by groups of animals was analyzed at different stages of exposure: before decompression, during decompression, within 1 minute after exposure, as well as in the interval from 1 to 5 minutes and from 5 to 19 minutes after exposure. In all groups vasoconstriction preceded decompression (i. e., reduced number of vessels in the frame), but in all of them vasodilation (increased number of vessels in the frame) occurred in the first minute after decompression. Interestingly, in the «drotaverine» group, the dynamics of changes was most pronounced: unlike other groups, vasoconstriction (0,24±0,177 %) continued during decompression, and expansion right after exposure was also highly expressed (1.034±0.997 %).

Conclusion. hyperemic changes and the severity of prolongation of these changes was shown to be different depending on the type of pharmacological effect and could be recorded by the experimental unit developed by the authors.

Introduction. Liver hemodynamics age-related features studying is promising area of portal and caudal vena cava and hepsatic artery of rats hemodynamics exploration.

Aim was to determine qualitative and quantitative hemodynamic paremeters of the laboratory rats caudal vena cava of different genders and ages.

Materials and methods. The study was conducted on 60 mongrel rats (males and females, 120–170 g) divided into three age groups. The first group included 20 rats aged 1 month, the second – 20 rats aged 6–12 months and the third – 20 rats aged more than 18–24 months. The study of caudal vena cava qualitative and quantitative hemodynamic parameters was performed by ultrasound scanners. Animals were anaesthesized by zoletil-xylazine. Digital data were processed by methods of variational statistics.

Results. All animals showed the antegrade caudal vena cava blood flow. The spectrum of blood flow differed in the number, shape of teeth and phase. The most animals showed three-phase spectrum not depend on the animals gender and age. The diameter of the vein did not depend on the gender. In the I and II age groups, the predominance of the volumetric blood flow rate in the CPV in males compared with females was within 10 % (R=0.98 and R=0.37, respectively), in the III age group, the relationship was not statistically significant (R=–0.03). The diameter and maximum systolic blood flow velocity in the caudal vena cava increased slightly (within 3 %) with the age of the animals (R=0.64 and R=0.43, respectively). Volumetric blood flow rate decreased within 4 % with increasing age (R=0.42).

Conclusion. The spectrum of rats caudal vena cava blood flow differed in the number, shape of waves and phase. In most animals it was three-phase. In all animals the direction of blood flow was antegrade. The phase of the spectrum was not affected by the animals gender and age. There was no statistically significant dependence of the diameter and linear velocity of blood flow on the gender. The volumetric blood flow rate was slightly higher in males (within 10 %) compared to females. The diameter and the maximum systolic blood flow velocity increased slightly (within 3 %) with the age of the animals. The indicator of the volumetric blood flow rate decreased within 4 % with increasing age.

Introduction. The evolution of the study of mitral valve ischemic dysfunction influenced by fundamental and experimental research in recent years has led to a change of mitral leaflets role as a static component of the mitral valve in the pathogenesis of ischemic mitral regurgitation especially in the chronic myocardial ischemia.

Objective. We report the clinical case of acute ischemic mitral regurgitation as a result of a chord rupture of the PML in a patient with unspecified duration of coronary artery disease without acute coronary syndrome and previous myocardial infarction including all stages of the diagnostic search and the results of surgical treatment.

Conclusion. While performing reconstructive correction of the ischemic mitral regurgitation the possibility of reverse remodeling of the leaflets should be considered in case of removal the myocardial ischemia triggering factor. And therefore it is necessary to perform a full and adequate myocardial revascularization that combined with a full correction of all morphofunctional mitral valve changes guarantees the freedom from residual and recurrent mitral regurgitation.

The COVID-19 infection leads to profound changes in coagulation among patients affected by the disease. High prevalence of thrombotic events and its different clinical manifestations forced medical society to reevaluate the existent guidelines and to find the new applicable treatment approaches. This case study report includes a brief review of latest guidelines and scientific manuscripts, pathogenic justification of proposed treatment methods, an example of successful treatment of 56 years old male with acute limb ischemia, nonsmoker, with no previous history of peripheral arterial disease, severely affected by coronavirus infection. Ongoing pandemic makes the aspects of active surgical treatment of COVID-19 patients with associated thrombotic complications playing crucial role to decrease the number of negative consequences of infection.