Respiratory Function of Mitochondria in Patients with Coronary Heart Disease with Implantable Cardioverter-Defibrillator.

We studied the respiratory activity of mitochondria in peripheral blood leukocytes from 36 patients with coronary heart disease (CHD) and a history of ventricular tachyarrhythmias required cardioverter-defibrillator implantation. The measurements were carried out in incubation buffers with different oxidation substrates (succinate and pyruvate-malate mixture). In pyruvate-malate incubation buffer, oxygen consumption rate and respiratory control coefficients in patients with triggered device did not differ significantly from those in patients without cardioverter-defibrillator triggering. At the same time, respiratory control coefficients were below the reference values. In succinate buffer, values of mitochondrial parameters were significantly lower in patients with triggered devices. Our findings indicate that mitochondria of patients with non-triggered cardioverters-defibrillators have better functional and metabolic plasticity. It was concluded that activity of respiratory processes in mitochondria could be an indicator that should be taken into the account when assessing the risk of developing ventricular tachyarrhythmias.

[Methylation of Regulatory Regions of DNA Repair Genes in Carotid Atherosclerosis].

The status of DNA methylation in the human genome changes during the pathogenesis of common diseases and acts as a predictor of life expectancy. Therefore, it is of interest to investigate the methylation level of regulatory regions of genes responsible for general biological processes that are potentially significant for the development of age-associated diseases. Among them there are genes encoding proteins of DNA repair system, which are characterized by pleiotropic effects. Here, results of the targeted methylation analysis of two regions of the human genome (the promoter of the MLH1 gene and the enhancer near the ATM gene) in different tissues of patients with carotid atherosclerosis are present. Analysis of the methylation profiles of studied genes in various tissues of the same individuals demonstrated marked differences between leukocytes and tissues of the vascular wall. Differences in methylation levels between normal and atherosclerotic tissues of the carotid arteries were revealed only for two studied CpG sites (chr11:108089866 and chr11:108090020, GRCh37/hg19 assembly) in the ATM gene. Based on this, we can assume the involvement of ATM in the development of atherosclerosis. "Overload" of the studied regions with transcription factor binding sites (according to ReMapp2022 data) indicate that the tissue-specific nature of methylation of the regulatory regions of the MLH1 and ATM may be associated with expression levels of these genes in a particular tissue. It has been shown that inter-individual differences in the methylation levels of CpG sites are associated with sufficiently distant nucleotide substitutions.

[Five-year dynamics adrenergic reactivity of erythrocytes after radio-frequency sympathic denervation of renal arteries in patients with resistant arterial hypertension].

AIM: To study the initial state of adrenergic reactivity and the five-year dynamics of the beta-adrenergic reactivity index of erythrocyte membranes and the manifestation of the antihypertensive effect of the procedure for radiofrequency destruction of sympathetic structures of the renal artery in patients with resistant arterial hypertension. SUBJECTS AND METHODS: The analysis included 42 patients with resistant arterial hypertension (RH). The renal denervation (RD) procedure of the kidneys was performed by endovascular bilateral transcatheter radiofrequency ablation of the renal arteries. The study of 24-hour blood pressure monitoring (BPM) and the determination of ß-adrenoreactivity of erythrocytes (ß-ARM) by changes in the osmoresistance of erythrocyte membranes were performed initially, 1 week, 6 months, 1, 2, 3 and 5 years after RD. Patients retrospectively, at a follow-up period of 6 months after RD, were divided into responders (decrease in blood pressure by 10 or more mm Hg) and non-responders (decrease in blood pressure less than 10 mm Hg). RESULTS: 6 months after the RD, the number of responders was 28 people (66.7%), after 5 years - 31 people (73.8%). At the time of inclusion in the study, the median ß-ARM in the group of non-responders was not significantly higher than in the group of responders. After 6 months after the RD procedure, the ß-ARM indicator in the non-responder group was significantly lower than in the responder group (p = 0.043). With further follow-up in the group of responders, an increase in the median ß-ARM was noted, which reached significant differences relative to the baseline values in the group at follow-up periods of 1 year (p = 0.036) and 5 years (p = 0.004) after RD. The change in the ß-ARM indicator in the non-responder group was wavy in nature, the changes did not reach the significance criteria. CONCLUSION: Renal denervation in 73.8% of cases is accompanied by a stable antihypertensive response for 5 years of observation and an increase in ß-ARM, which may indicate the implementation of compensatory mechanisms in conditions of increasing activity of the sympathoadrenal system in response to a decrease in blood pressure.

Age Peculiarities of Respiratory Activity and Membrane Microviscosity of Mitochondria from Rat Cardiomyocytes.

We studied respiratory activity and microviscosity of mitochondrial membranes from the left ventricular myocardium of 2-month-old (n=8) and 15-month-old (n=8) rats. The respiratory control (RC) during substrate phosphorylation was calculated as the ratio of oxygen absorption rates in the presence of ADP and after its utilization. In 2-month-old rats, RC was 4.66 (4.56; 4.71); in 15-month-old animals, it was significantly (р<0.05) lower: 3.57 (3.50; 3.62). Pyrene probe eximerization indices for regions of protein-lipid and lipid-lipid interactions in mitochondria of 2-month-old animals were significantly lower than in the group of 15-month-old rats, which indicated reduced microviscosity of the lipid environment of proteins. Thus, the decrease in RC of mitochondria from the left ventricle of 15-month-old animals and the increase in the microviscosity coefficients of their membranes indicate age-related changes in the structural and functional activity of mitochondria.

Erythrocyte membranes beta-adrenoreactivity changes after renal denervation in patients with resistant hypertension, relationship with antihypertensive and cardioprotective intervention efficacy.

Aim      To study the functional condition of sympathoadrenal system as evaluated by beta-adrenoreactivity of erythrocyte membranes (beta-ARM) during two years following renal denervation (RD) in patients with resistant arterial hypertension (RAH) and to determine the relationship of this index with long-term antihypertensive and cardioprotective effectivity of this invasive treatment.Material and methods  The study included 48 patients (mean age, 57.2±8.7 years, 18 men) with RAH on a stable antihypertensive therapy. Averaged daily systolic and diastolic blood pressure (SBP and DBP) and levels of beta-ARM were determined at baseline and in 7 days and 2 years following RD. Measurement of beta-ARM was based on beta-adrenoblocker inhibition of erythrocyte hemolysis induced by exposure to hypo-osmotic environment. The beta-adrenoblocker binds to erythrocyte membrane beta-adrenoceptors to prevent the erythrocyte destruction. Increased values of beta-ARM reflect a decrease in the number of functionally active erythrocyte membrane beta-adrenoceptors associated with long-term sympathetic hyperactivity.Results For two years of follow-up, values of average daily BP decreased from 160.4±16.0 / 88.1±14.6 to 145.3±19.3 / 79.4±13.6 mm Hg. At 7 days, the number of beta-ARM had decreased in the group of RD responders (р=0.028) who at two years had decreased their BP by 10 mm Hg or more, while in the group of non-responders, the number of beta-ARM remained unchanged. At one week, beta-ARM values correlated with changes in SBP and DBP (r= -0.54; р<0.05) and with left ventricular myocardial mass (LVMM) (r= -0.36; р<0.05) at two years of follow-up whereas beta-ARM delta at one week was interrelated with the renin concentration in the long-term (r= -0.44; р<0.05). At two years, the content of beta-ARM was increased in both groups.Conclusion      The decrease in beta-ARM content at 7 days after RD shows the procedure efficacy and allows an expectation of clinically significant decreases in BP and LVMM in the long-term after the surgical treatment. At two years after the intervention, the content of beta-ARM increased, and the BP decrease was apparently due to some other mechanisms.

[Dynamics of adreneractivity after transfer of myocardial infarction: annual observation].

AIM: To study the change in the -adrenergic reactivity of red blood cell membranes in patients during the first year after acute myocardial infarction. MATERIALS AND METHODS: The study included 25 patients with acute myocardial infarction (AMI) who signed informed consent to participate in the study. The erythrocyte membrane -adrenoreactivity index (-ARM) was determined in venous blood samples upon admission to the intensive care unit, one day after admission, 6 and 12 months after the index MI was transferred using the BETA-ARM-AGAT reagent kit (Agat-Med, Russia). RESULTS: According to the results of dynamics assessment of -APM during the first day, patients included in the study were divided into 2 groups. Group 1 (n=14) included patients who had an increase in -APM in the first day, and group 2 (n=21) included patients in whom -ARM either did not change or decreased. At the time of admission to the hospital in the formed groups, there were no differences in the -APM index and clinical and anamnestic characteristics. A day after hospitalization, the value of -APM in group 1 significantly exceeded the same indicator in group 2 (p=0.02). At the periods of 6 and 12 months, the -APM indices in the groups did not differ. In the 2nd group of patients, the progression of chronic heart failure to one or more functional classes (NYHA) was significantly more often compared with the 1st group. CONCLUSION: The study showed that on the first day in patients with AMI, both an increase and a decrease in the activity of the sympathoadrenal system are possible with a further leveling of these differences over the next year. For a group of patients with decreased activity of sympathoadrenal system on the first day, a more unfavorable course of heart failure in the post-infarction period is characteristic.

[Age-dependent changes in adrenoreactivity in experimental postinfarction cardiosclerosis.]

Presently, there is growing interest in studying the activity of the sympathoadrenal system in the aging process of the body and the development of diseases of the cardiovascular system associated with age. The intention of the research is evaluation of ß-adrenoreactivity of erythrocyte membranes (ß-ARM) of intact rats and rats with postinfarction cardiosclerosis at the age of 4, 12 and 24 months: the first group contained twenty 4 months old animals; the second group - twenty 12 months old animals; the third group - twenty 24 months old animals. In the each group were distinguish 10 intact rats and 10 experimental rats, that have postinfarction cardiosclerosis (PICS) modeled by coronary occlusion. The experiments was completed on 60 male-rats. It was shown, that in intact animals the indicator of ß-ARM significantly decreases by 12 months in relation to the group of 4 monthly animals. In the groups of intact animals of 12 and 24 months, there were no significant differences in ß-ARM. The severity of cardiac hypertrophy in animals with PICS was inversely related to age - 4>12>24 months old. Formed PICS in animals aged 4 and 12 months was accompanied by a expressed increase of ß-ARM, in animals 24 months with PICS ß-ARM did not significantly change. Changes in the ß-ARM index characterizing the state of the CAS receptor link under PICS conditions are age-related, in adults 12 months of age with PICS, an increase in ß-ARM relative to the parameter at 4 months. animals indicates compensatory desensitization of ß-adrenergic receptors upon activation of CAS in response to the development of contractile myocardial insufficiency. In the age group of 24 months with the formed cardiosclerosis, compensatory activation of CAS is manifested to a lesser extent.

Peculiarities of Cell Seeding on Electroformed Polycaprolactone Scaffolds Modified with Surface-Active Agents Triton X-100 and Polyvinylpyrrolidone.

We compared the capability of human fibroblasts to populate porous polycaprolactone (PCL) scaffolds modified during fabrication with surface-active agents Triton Ð¥-100 (type 1 scaffold) and polyvinylpyrrolidone (type 2 scaffold). The mean fiber diameter in both scaffolds was almost the same: 3.90±2.19 and 2.46±2.15 µ, respectively. Type 1 scaffold had higher surface density and hydrophilicity, when type 2 scaffold was 1.6 times thicker. The cells were seeded on the scaffolds by the dynamic seeding technique and then cultured in Petri dishes with nutrient medium in a humid atmosphere. During 3-day culturing, no cell release from the matrix was noted. DAPI staining proved the presence of cells in both scaffolds. However, in type 1 scaffold the cells populated the whole thickness, while in type 2 scaffold, the cells were present only in the superficial layer. These findings suggest that PCL scaffolds modified with Triton Ð¥-100 or polyvinylpyrrolidone are not cytotoxic, but the structure of the scaffold treated with Triton Ð¥-100 is more favorable for population with cells.

[Age features peripheral link erythron rats and its status with experimental cardiosclerosis].

Studied the performance of the peripheral unit erythrone rats aged 4 months (1st group) 12 months (2nd group) and 24 months (3rd group). Each age group (n=20) consisted of 10 intact animals and 10 animals c postinfarction cardiosclerosis (PICS). In the group of animals 24 months of age was showed an increase in the number of erythrocytes in the absence of difference in the amount of reticulocytes. Expressed anisocytosis and decrease in hemoglobin synthesis in animals of this age group suggests that the age-related disorders maturation of erythroid cells. The development of post-infarction myocardial remodeling has not affected polycythemia typical for animals of older age group. At the same time a significant increase in the reticulocyte count of peripheral blood smears was observed for this group of animals. Development of PICS for animals extreme age groups leads to a smoothing interage differences, noted in the animals in the intact condition.

Rhythmoinotropic Response of Papillary Muscles in Rats with Different Severity of Postinfarction Cardiosclerosis.

We studied the dependence of post-rest positive inotropic response of isolated rat papillary muscles subjected to rhythmic stimulation on severity of postinfarction cardiosclerosis developed during 6 weeks after occlusion of the left descending coronary artery. The isolated papillary muscles were perfused with oxygenated Krebs-Henseleit solution and electrically stimulated at a rate of 0.5 Hz. In all rats, coronary occlusion provoked postinfarction cardiosclerosis with the formation of a scar occupying 20-50% (min-max of the sample) of the left ventricular wall. Despite the presence of large postinfarction scar in all rats, the positive post-rest inotropic responses greatly varied. The post-rest response in rats with scar occupying <37% left ventricular wall was similar to that in intact animals, but rats with scar area >44% demonstrated dramatically decreased inotropic response to rest periods.

Peculiarities of Cell Seeding on Polylactic Acid-Based Scaffolds Fabricated Using Electrospinning and Solution Blow Spinning Technologies.

We studied the possibility of seeding bone marrow-derived stromal cells onto polylactic acid-based scaffolds fabricated by electrospinning and solution blow spinning technologies. The cells were applied to the scaffolds by dynamic seeding and scaffolds were then cultured in Petri dishes in culture medium for 3 days. Cell migration to the Petri dish surface was noted only for scaffolds fabricated by electrospinning technology, but DAPI staining confirmed the presence of cells in both scaffolds. The mean number of cells in scaffolds fabricated by electrospinning and solution blow spinning was 56±9 and 81±6, respectively. The scaffold fabricated by solution blow spinning was more effectively (p<0.05) colonized by cells due to its more optimal spatial structure.

[Association of ITGB3, P2RY12, and CYP2C19 gene polymorphisms with platelet functional activity in patients with coronary heart disease during dual antiplatelet therapy]. / Assotsiatsiia polimorfizmov genov ITGB3, P2RY12, CYP2C19 s funktsional'noi aktivnost'iu trombotsitov u patsientov s ishemicheskoi bolezn'iu serdtsa na fone dvukhkomponentnoi antiagregantnoi terapii.

AIM: To assess the association of CYP2C19 G681A, P2RY12 H1/H2, and ITGB3 T1565C polymorphisms with the extent of platelet aggregation in patients with coronary heart disease (CHD) during antiplatelet therapy. SUBJECTS AND METHODS: 166 male patients with CHD, living in the Western Siberian Region, were examined. All the patients underwent a test for platelet aggregation induced by ADP (2.5 and 5.0 µm) and epinephrine (0.2 µm). Genotyping was performed using an allele-specific polymerase chain reaction technique. RESULTS: The polymorphic variants of the P2RY12 and ITGB3 genes were ascertained to have no impact on the extent of platelet aggregation in patients receiving clopidogrel and acetylsalicylic acid. An association was found between CYP2C19 681A allele carriage and the increased extent of platelet aggregation induced by ADP. CONCLUSION: The carriage of the cytochrome P450 CYP2C19 681A allele rather than platelet receptor gene polymorphisms determines a risk for clopidogrel resistance in patients with CHD.

Differences in the Force-Interval. Relationship of Isolated Human Myocardium with Chronic Coronary Artery Diseasein Patients with and without Type 2 Diabetes Mellitus and the Role of Ca²âº-ATPase of Sarcoplasmic Reticulum.

We studied the force--interval relationship of human myocardium in coronary artery d isease (CAD) and CAD with concomitant diabetes mellitus and evaluated its dependence on the level of expression of Ca²âº-AT Pase of the sarcoplasmic reticulum (SR). We used the myocardial biopsies obtained during coronary artery bypass grafting with the use of cardiopulmonary bypass techniques. The study included patients with chronic CAD and patients with CAD and concomitant type II diabetes mellitus. It was found that patients with CAD with and without diabetes with similar clinical signs had both negative and positive dynamics of the force-interval relationship. The positive. force-interval relationship was associated with the ''high level" of Ca²âº-ATPase, while the negative force-interval relationship was associated with the "low level" of this protein. In cases of small CAD and diabetes duration, the positive "force-interval" relationship is more pronounced and corresponds to a higher level of expression Ca²âº- ATPase in the SR than in case of CAD without diabetes mellitus.

Age-Dependent Changes in Na(+),K(+)-ATPase Activity and Lipid Peroxidation in Membranes of Erythrocytes during Cardiosclerosis Development in Rats.

Activity of Na(+),K(+)-ATPase was measured in erythrocyte ghosts of 4- and 12-month-old rats, intact and with postinfarction cardiosclerosis. Enhanced accumulation of secondary LPO products and reduced activity of Na(+),K(+)-ATPase were observed in erythrocyte ghosts of 12-month-old rats. The development of postinfarction cardiosclerosis in 4-month-old rats was accompanied by enhanced accumulation of LPO products and decreased activity of Na(+),K(+)-ATPase. In comparison with young rats with postinfarction cardiosclerosis, 12-month-old rats with this pathology were characterized by less pronounced decrease in Na(+),K(+)-ATPase activity and increase in accumulation of LPO products in comparison with intact control.

[Influence of Fatty Acids on Oxygen Consumption in Isolated Cardiomyocytes of Rats with Ischemic or Diabetic Heart Disease].

BACKGROUND: one of the reasons of violation of the functional viability of the myocardium is considered to be the oxygen deprivation and lack of energy. The reason is the inhibitory effect of fatty acids on glucose oxidation. Recently, however, new data have been published proving the need for fatty acids and their importance in the maintenance and regulation of the functional activity of the myocardium in chronic pathology. OBJECTIVE: to investigate the influence of free polyunsaturated and saturated fatty acids (FA) on the oxygen uptake of isolated cardiomyocytes in intact rats and animals with ischemic or diabetic heart disease. METHODS: the executed non-randomized controlled study. It includied 3 groups of male rats of Wistar line (weight 250-300g) with 10 animals in each group. Myocardial infarction ("heart attack" group) was caused by ligation of the left coronary artery, diabetes ("diabetes" group)--by intraperitoneal injection of streptozotocin, and "control" group (intact animals). Myocardial infarction caused by ligation of the left coronary artery, and diabetes by intraperitoneal injection of streptozotocin. Isolated cardiac myocytes were obtained by the enzymatic method. Oxygen consumption was assessed polarographically at different saturation incubation medium with oxygen ([O2] ≤ 8 mg/l and ([O2] ≥ 16 mg/l). Arachidonic and palmitic acids were applied as fatty acids. RESULTS: It is established that the introduction of the incubation medium 20 µm arachidonic or palmitic fatty acid significantly increased the oxygen consumption of intact cardiomyocytes of rats. Both at the ischemic and at the diabetic injury to the heart the opposite result was obtained. The most pronounced decrease in oxygen consumption was indicated in the group with diabetes mellitus. CONCLUSION: The inhibitory effect of LCD on the rate of oxygen consumption may be associated with the influence of the ischemic or diabetic injury to the heart on the barrierfunction ofmitochondrial membranes of cardiomyocytes, the activity of membrane-associated enzymes and their associated processes.

[Association of I/D and -786 Polymorphisms of ACE and NOS3 Genes With Features of the Course of Ischemic Heart Disease and Diabetes Mellitus Type 2].

AIM: to study relationship of ACE insertion-deletion (I/D) polymorphism and NOS3 T-786C polymorphism with characteristics of the course of ischemic heart disease (IHD) at the background of diabetes mellitus. MATERIALS AND METHODS: Were examined 114 patients with IHD, 29.8% of patients had type 2 diabetes mellitus. ACE and NOS3 polymorphisms were determined by allele-specific polymerase chain reaction with primers by "Lytech". RESULTS: Patients with combined pathology belonged to older age group, had increased frequency of obesity and predominance of functional class II chronic heart failure. In this group we detected association of D allele of the ACE gene with higher frequency of dyslipidemia and obesity. Among patients with IHD without diabetes we observed associations of ACE I/D and NOS3 T-786C polymorphisms (close and moderate, respectively) with severity of effort angina. We also found that frequency of dyslipidemia among carriers of II and TT genotypes was lower than among carriers of other genotypes. CONCLUSION: Presence of type 2 diabetes as background pathology leads to a change of character of association of ACE I/D and NOS3 T-786C polymorphisms with clinical characteristics of patients with IHD.

[Possibility of evaluating the effectiveness of renal artery sympathetic denervation in resistant hypertension early after radiofrequency ablation]. / Vozmozhnost' otsenki effektivnosti simpaticheskoi denervatsii pochechnykh arterii pri rezistentnoi arterial'noi gipertonii v rannie sroki posle provedeniya radiochastotnoi ablyatsii.

AIM: to investigate time course of changes in the adrenoreactivity (AR) of erythrocyte membranes (EM) after radiofrequency ablation of the synaptic nerves of the renal arteries (RA) in patients with resistant hypertension (RH) and to assess whether this indicator can be used for the early evaluation of the efficiency of an invasive intervention into the RA. SUBJECTS AND METHODS: 24 patients with RH, who received full-dose antihypertensive therapy with at least three drugs, including a diuretic, were examined. Renal sympathetic denervation (RSD) was carried out by endovascular radiofrequency ablation (RFA) of the RA. 24-hour blood pressure (BP) monitoring and determination of the ß-adrenoreactivity (ß-AR) of EM were performed, by taking into account the change in erythrocyte osmoresistence at baseline and 1 and 24 weeks after RFA. The therapy was not changed during the observation. RESULTS: The patients included in the study were divided into 2 groups. One week following RSD, 15 patients of Group 1 were noted to have a decrease in the ß-AR of EM by 10 conditional units or more; average daily systolic BP (SBP) and diastolic BP (DBP) reduced by 8.3 and 2.8 mm Hg, respectively. In 9 patients of Group 2, the ß-AR of EM was unchanged in this observation period or increased compared with baseline. In this group, the decrease in average daily SBP and DBP was noted to be less pronounced than that in Group 1 (by 1.4 and 1.5 mm Hg, respectively). At 24 weeks after RSD, Group 1 was seen to have an effective daily decrease in average daily SBP and DBP by 25.6 and 14.3 mm Hg, respectively (p=0.01 and 0.05). The average value of the ß-AR of EM significantly declined compared with baseline. In Group 2, no statistically significant changes were reported; SPB and DBP lowered by 7.0 and 3.0 mm Hg, respectively. There was a significant decrease in the ß-AR of EM compared with that at week 1. CONCLUSION: The decline in the ß-AR of EM within the first week after RFA is suggestive of the decreased activity of the sympathoadrenal system and may be used as an early efficiency index of RSD after the procedure.

[Criteria for selecting patients with resistant hypertension for a renal sympathetic denervation]. / Kriterii otbora bol'nykh s rezistentnoi arterial'noi gipertoniei dlya simpaticheskoi denervatsiya pochek.

AIM: to define and develop a procedure that can select patients with resistant hypertension (RH) for a renal sympathetic denervation (RSD) procedure, by being orienting to the specific initial values of ß-adrenoreactivity (ß-AR) and systolic blood pressure (SBP). SUBJECTS AND METHODS: The analysis included 23 RH patients receiving the maximally tolerable doses of 4 antihypertensive drugs. The investigations involving BP control and a Russian spectrophotometric procedure for determining ß-AR in terms of the change in the osmoresistance of erythrocyte membranes (EM) were performed at baseline and 4 and 24 weeks. RSD was carried out using endovascular radiofrequency ablation of the renal arteries. The therapy was not changed during the observation. RESULTS: If SBP was >170 mm Hg and ß-AR of EM >40 conditional units (CUs) at baseline, ΔSBP was 17.68±3.24 mm Hg and the efficiency of RSD was 100%. When SBP was <170 mm Hg and ß-AR of EM <40 CUs at baseline, ΔSBP was 0.97±4.21 mm Hg (p>0.05) and the efficiency of RSD was low. CONCLUSION: The overall estimate of baseline SBP and ß-AR of EM in patients with RH could determine the expediency of the RSD procedure in order to lower BP. The proposed procedure can optimize the selection of patients and enhance the efficiency of RSD in the treatment of RH.

Development of an experimental model of cardiac failure combined with type I diabetes mellitus.

The doses and mode of streptozotocin injection for modeling heart failure combined with type 1 diabetes mellitus have been determined. Combined disease was induced in animals by injecting the selected streptozotocin dose (60 mg/kg intraperitoneally) at the stage of heart failure formation (2 weeks after coronary occlusion). This protocol of experiment led to development of hyperglycemia, body weight loss, and formation of myocardial cicatrix and hypertrophy corresponding to signs of heart failure paralleled by diabetes mellitus.

Effect of model biological media of stability of complex of silver nanoparticles applied onto silicon nitride substrate.

We studied stability of complexes of silver nanoparticles and silicon nitride before and after their interaction with liquid media and after passing through bacterial filters. According to scanning electron microscopy data, contact with fluids and passage through bacterial filters reduced the content of silver nanoparticles in complexes compared to that in initial complexes. It was shown that these differences depended on both initial characteristics of the examined samples and the used liquid media. The complex Ag/Si3N4 obtained after 5 silver reduction cycles and containing 15% α- and 85% ß-modifications of silicon nitride (sample No. 2) was characterized by maximum stability. Culture medium produced more aggressive effect on stability of the studied complexes. We concluded that the effect of culture media on stability of silver nanoparticles-silicon nitride complexes depends on phase composition of the substrate and method of application of silver nanoparticles.