The review presents evidence of the participation of low-density lipoproteins (LDL) modified by low molecular weight dicarbonyl compounds formed during freeradical oxidation of lipids (malondialdehyde) and carbohydrates in the development of endothelial dysfunction and atherosclerotic vascular lesions. The authors believe that it is they, and not oxidized (hydroperoxide-containing) LDL, that are the main factors of pathogenesis. The role of dicarbonyl-modified LDL in LOX-1 dependent induction of processes leading to the development of endothelial dysfunction is discussed. The results of studies proving that damage to the glycocalyx (a layer of macromolecules that prevent the development of endothelial dysfunction) covering the luminal surface of the endothelium is caused by hyperproduction of reactive oxygen species. Ways of pharmacological correction of free-radical oxidation processes are discussed, due to which inhibition of atherogenesis and diabetogenesis can be achieved.

Antioxidant and anti-ischemic properties of the pharmacological agonist of galanin receptor GalR2 WTLNSAGYLLGPβAH (Gal) and its C-terminal fragment, dipeptide carnosine (βAH), were studied in the model of regional ischemia and reperfusion of the rat heart in vivo in the dose range of 0.5-5.0 mg/kg and Cu²⁺-induced free radical oxidation of low density lipoproteins (LDL) of human plasma in vitro for peptide concentrations of 0.01 mM and 0.1 mM. Gal was obtained by automatic solid phase synthesis using the Fmoc methodology; its structure was characterized by 1H-NMR spectroscopy and MALDI-TOF mass spectrometry. Intravenous administration of the optimal dose of Gal (1 mg/kg) to rats after ischemia was more effective than carnosine in reducing of the myocardial infarct size and the activity of creatine kinase-MB and lactate dehydrogenase in blood plasma at the end of reperfusion. It also improved the metabolic state of the reperfused myocardium and reduced the formation of peroxidation products during reperfusion. Gal reduced more effectively the formation of adducts of hydroxyl radicals in the interstitium of the area at risk (AAR) of the rat heart than carnosine. Carnosine at a dose of 1 mg/kg more effectively increased the activity of catalase and glutathione peroxidase in the AAR by the end of reperfusion compared to Gal. In a model of Cu²⁺-initiated oxidation of human plasma LDL 0.1 mM carnosine demonstrated a significantly more pronounced reduction in the formation of lipid radicals compared to Gal. The results show that Gal can be considered as a promising agent that reduces myocardial injury during reperfusion and oxidative stress.

Abstract Background Abdominal circulation plays the important physiological role for structure and function of the digestive system, maintenance of nutrient homeostasis. Purpose To study the features of abdominal hemodynamics in patients with visceroptosis. Methods We studied 69 patients (mean age 22.28±3.7 years) with splanchnoptosis (visceroptosis) and 52 age- and sex- matched patients without splanchnoptosis (controls). Exclusion criteria: a history of digestive system surgery of taking blood circulation activating drugs. Doppler ultrasonography of the common hepatic artery, splenic artery, superior mesenteric artery, portal vein was performed on an empty stomach and 30 minutes after a food sample (standardized for proteins (14 g), fats (10 g) and carbohydrates (45 g)) using the Sonoace-8000 ultrasound scanner (Medison, South Korea). The data were analyzed using the Statistica-6 packages. Results There were no differences in hemodynamic parameters of fasting abdominal blood flow (ABF). After a food testing, in the postprandial period the ABF in all vessels in patients with splanchnoptosis was lower than in controls: the portal vein blood flow (BF) 1124,0 [1030,0–1419,0] ml/min vs 1373,0 [1136,0–1567,5] ml/min respectively (U=433,5; Z=−2,1; p=0,0342); the common hepatic artery BF 341,0 [295,0–394,0] ml/min vs 412,0 [331,0–521,0] ml/min respectively (U=335,0; Z=−2,3; p=0,0218); the splenic artery BF 396,0 [292,0–538,0] ml/min vs 502,0 [394,0–594,0] ml/min respectively (U=328,0; Z=−2,1; p=0,0399); the superior mesenteric artery BF 988,0 [837,0–1272,0] ml/min vs 1136,5 [992,0–1465,0] ml/min respectively (U=1625,5; Z=−2,2; p=0,0314). Changes in ABF were correlated with splanchnoptosis: the portal vein BF with any ptosis (rs=−0,21; p<0.05), the common hepatic artery BF with gastroptosis (rs=−0,38; p<0.05), the superior mesenteric artery BF with colonoptosis (rs=−0,86; p<0.05). The peripheral vascular resistance was correlated with the common hepatic artery BF (rs=−0,46; p<0.05), with the splenic artery BF (rs=−0,33; p<0.05) and with the superior mesenteric artery BF (rs=−0.79; p<0.05). Conclusions Patients with splanchnoptosis in the postprandial period have low volumetric BF in abdominal aorta vessels. This can be associated with the length of the mesenteric vessels, which undergoes the greatest changes in splanchnoptosis. Food testing reveals latent BF deficit in patients with splanchnoptosis. Funding Acknowledgement Type of funding sources: None.

Background. In view of the worsening forecast for global temperature rise worldwide, it seems relevant to study the effects of abnormal heat waves on systemic regulatory processes in people with chronic diseases, in particular coronary artery disease (CAD).Aims. This study aimed to investigate the effect of hyperthermia on oxidative stress parameters in patients with various severity of CAD and in healthy subjects.Materials and methods. We studied the level of malonic dialdehyde (MDA) and the activity of Cu,Zn-containing superoxide dismutase (Cu,Zn-SOD) in healthy subjects under conditions of 30-day long simulated hyperthermia and in patients with different severity of CAD after the summer heat wavesResults. We revealed signs of oxidative stress in healthy volunteers during model hyperthermia that manifested as an increase in content of MDA in blood plasma. At the same time we observed increasing activity of Cu,Zn-SOD in erythrocytes that utilizes reactive oxygen species. The increase of Cu,Zn-SOD activity started with a certain latency what also can be explained by de novo enzyme biosynthesis induction. We also studied oxidative stress parameters in patients at high and moderate cardiovascular risk according to the SCORE risk chart with uncomplicated CAD course and in patients with complicated CAD with severe coronary damage according to angiography during the summer heat waves. We observed accumulation of MDA in blood plasma and increasing activity of erythrocyte Cu,Zn-SOD in patients with uncomplicated CAD. At the same time we noted that accumulation of MDA in blood plasma was not followed by any increase in activity of red blood cell Cu,Zn-SOD in patients with severe complicated CAD. This fact indicates dysregulation of free radical processes in patients with severe course of CAD during the heat waves.Conclusions. The dysregulation of free-radical processes in patients with a severe clinical course of CAD has been revealed.

The use of the anticancer drug doxorubicin (Dox) is limited by its cardiotoxic effect. The aim of this work was to study the effect of a new synthetic agonist of the galanin receptor GalR1-3 [βAla14, His15]-galanine (2-15) (G) on the metabolism, antioxidant enzyme activity, and cardiac function in rats with cardiomyopathy (CM) caused by chronic administration of Dox. Coadministration of peptide G and Dox significantly increased the fractional shortening (FS) and ejection fraction (EF) by an average of 30 ± 4% compared with the indices in the Dox group. The reduced severity of cardiac dysfunction under the action of G was accompanied by a 2.5-fold decrease in the activity of creatine kinase-MB (CK-MB) in blood plasma. The protective mechanism of the action of peptide G is caused by a reduced lipid peroxidation (LP) that is due to the increased activity of Cu,Zn superoxide dismutase (Cu,Zn-SOD) and glutathione peroxidase (GSH-Px) in the damaged heart. Administration of peptide G significantly increased the adenine nucleotide pool (ΣAH), ATP content, and the levels of phosphocreatine (PCr) and total creatine (ΣCr) in the damaged myocardium. It also reduced lactate accumulation relative to its content in the Dox group. The better energy supply of cardiomyocytes after treatment with peptide G prevented the accumulation of cytotoxic ammonia and disruption in the metabolism of the key myocardial amino acids (glutamic acid (Glu), aspartic acid (Asp), and alanine (Ala)). Peptide G significantly improved the morphological parameters of the heart in rats treated with Dox. The results show promise in using peptide G to efficiently correct functional, morphological, and metabolic damage to the heart caused by anthracycline chemotherapy.

Aim. To assess the influence of coronary heart disease patients (CHD) therapy with statins or PCSK9 inhibitors influence on the level of oxidatively modified low density lipoproteides (LDL) and activity of erythrocyte Se-glutathione peroxidase (GSH-Px).Material and methods. To the study, CHD patients were included (9-10 males per group), who during 6 months were undergoing statin therapy — 40 mg per day of pravastatin (group 1) or 0,4 mg per day of cerivastatin (group 2), as the therapy with PCSK9 inhibitor — 420 mg per month evolocumab (group 3) during 1 year. The level of lipohydroperoxide in LDL (LOOH-LDL) was measured in the groups 1 and 2 with the modified method and usage of Fe-xilenolorange; content of oxidized LDL (oxLDL) in the group 3 — with immune chemistry method (assays Mercodia, Sweden). Activeness of GSH-Px in all groups was assessed with the modified methods bound with glutathione reductase system and tret-buthyl hydroperoxide as a substrate.Results. Simultaneously with the decrease of LDL cholesterol in the groups 1 and 2 there was significant increase (in the group 2 — 6-7 times in 3-6 months of therapy) of the level of LOOH-LDL. In the group 2 there was marked significant decrease of GSH-Px activity beginning from the month 3. In the group 3, with decreased LDL cholesterol there was significant decline in oxLDL with changed activity of GSH-Px.Conclusion. Statins, effectively decreasing the level of LDL cholesterol, simultaneously induce the oxidation of LDL and decrease the activity of GSH-Px. Inhibitor PCSK9 not only does effectively decrease the level of LDL cholesterol, but also the content of oxLDL, not leading to decreased GSH-Px activity.

Aim. To study the oxidative damage of biopolymers (proteins and nucleic acids) in blood of patients with type 2 diabetes mellitus (DM). Materials and methods. In the blood of 50 patients with DM and 25 patients without disorders of carbohydrate metabolism were estimated: the level of oxidized low-density lipoprotein (oxLDL) by immunochemical method, the content of SH-groups in plasma proteins, the activity of Cu, Zn-superoxide dismutase (SOD) in erythrocytes, the length of telomere in leukocyte DNA, the level of 8-hydroxy-2'-deoxygunosine (8-oxo-dG) in plasma and urine. Results and discussion. It is shown that in DM patients the level of oxLDL increases and the content of SH-groups in proteins and peptides of the blood plasma decreases, which indicates the development of oxidative stress. In addition, a carbonyl-dependent modification of erythrocyte SOD was detected in DM patients, as well as oxidative DNA destruction (decrease in telomere length in leukocytes and an increase in the level of 8-oxo-dG in blood plasma and urine). Conclusion. On the basis of the definition of a complex of correct indicators, a multiple oxidative modification of biopolymers of blood (proteins and DNA) was detected in patients with DM.

Aim. To assess the influence of coronary heart disease patients (CHD) therapy with statins or PCSK9 inhibitors influence on the level of oxidatively modified low density lipoproteides (LDL) and activity of erythrocyte Se-glutathione peroxidase (GSH-Px). Material and methods. To the study, CHD patients were included (9-10 males per group), who during 6 months were undergoing statin therapy — 40 mg per day of pravastatin (group 1) or 0,4 mg per day of cerivastatin (group 2), as the therapy with PCSK9 inhibitor — 420 mg per month evolocumab (group 3) during 1 year. The level of lipohydroperoxide in LDL (LOOH-LDL) was measured in the groups 1 and 2 with the modified method and usage of Fe-xilenolorange; content of oxidized LDL (oxLDL) in the group 3 — with immune chemistry method (assays Mercodia, Sweden). Activeness of GSH-Px in all groups was assessed with the modified methods bound with glutathione reductase system and tret-buthyl hydroperoxide as a substrate. Results. Simultaneously with the decrease of LDL cholesterol in the groups 1 and 2 there was significant increase (in the group 2 — 6-7 times in 3-6 months of therapy) of the level of LOOH-LDL. In the group 2 there was marked significant decrease of GSH-Px activity beginning from the month 3. In the group 3, with decreased LDL cholesterol there was significant decline in oxLDL with changed activity of GSH-Px. Conclusion. Statins, effectively decreasing the level of LDL cholesterol, simultaneously induce the oxidation of LDL and decrease the activity of GSH-Px. Inhibitor PCSK9 not only does effectively decrease the level of LDL cholesterol, but also the content of oxLDL, not leading to decreased GSH-Px activity.

The interaction of superoxide radical anion (O2 •−) with active dicarbonyls (methylglyoxal, glyoxal, and malonic dialdehyde) was studied. It was demonstrated that glyoxal and methylglyoxal inhibited superoxide-dependent accumulation of formazan; however, malonic dialdehyde stimulated this process. The formation of O2 •− in these experiments occurred during the decomposition of the SOTS-1 azo initiator. On the other hand, all of the studied dicarbonyls in this system of O2 •− generation competed for superoxide with the TIR ON spin trap. These compounds also inhibited luminal-dependent chemiluminescence during the AIBN azo initiator-induced peroxidation of liposomes from the egg phosphatidylcholine. A mechanism for the antiradical and antioxidant effects of the studied dicarbonyls, assuming the production of free radical intermediates in their reactions with O2 •− or its protonated form, is proposed.

Methylglyoxal at a concentration of 5 mM caused a significant inhibition of superoxide anion radical (O2 ·-) comparable to the effect of Tirone. In the process of O2 ·- generation in the system of egg phosphatidylcholine liposome peroxidation induced by the azo-initiator AIBN, a marked inhibition of chemiluminescence in the presence of 100 mM methylglyoxal was found. At the same time, methylglyoxal did not inhibit free radical peroxidation of low-density lipoprotein particles, which indicates the absence of interaction with methylglyoxal alkoxyl and peroxyl polyenoic lipid radicals. These findings deepen information about the role of methylglyoxal in the regulation of free radical processes.

We have suggested that the molecular mechanism of vascular wall damage in diabetes is not substantially different from that in atherosclerosis. Thus, it can be assumed that aldehyde-modified LDL should be eliminated from the blood stream with much greater speed than non-oxidized LDL. In the available literature there is information about the clearance of native human LDL from the bloodstream, whereas information on the clearance of the aldehyde-modified LDL in animals or humans was not found. Based on this, the present work is devoted to the clearance of aldehyde-modified LDL of rabbits and humans introduced into the bloodstream of rabbits. We investigated the clearance of glyoxal-, methylglyoxal- and MDA-modified LDL from the bloodstream of rabbits. We used biotinylated LDL of rabbit blood plasma and FITC-labeled LDL of human blood plasma. LDL was isolated with preparative ultracentrifugation in NaBr gradient. It was shown that glyoxal- and methylglyoxal-modified LDL of rabbits and humans circulated in the bloodstream for the same time as native LDL while MDA-modified LDL was rapidly eliminated from the bloodstream. The data obtained indicated the possibility of greater atherogenic potential of glyoxal- and methylglyoxal-modified LDL as they circulate in the bloodstream for a rather long time. At the same time, MDA-modified LDL is likely to be exposed to enhanced elimination by macrophages after their "linkage" to blood cells.

D-fructose strongly stimulates peroxidation of natural lipid-protein supramolecular complexes in vitro regardless of the oxidation initiation method. Fructose (ketose) intensifies free radical peroxidation to a much greater extent than glucose (aldose), which is important for the etiology and pathogenesis of diabetes mellitus.

The effects of C-terminal fragment of natural peptide apelin-12 H-Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Met-Pro-Phe-OH (A12) and its structural analog H-(N α Me)Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-OH (AI) on Cu 2+ -induced free radical oxidation of low-density lipoprotein in human blood plasma and activity of commercially available enzymes superoxide dismutase and catalase in a concentration range of 0.01-1 mM were examined. A12 and AI had no effect on superoxide dismutase and catalase activities during 24-h co-incubation with these enzymes at 4°C. When used in a concentration of 1 mM, A12 and AI decreased the maximum low-density lipoprotein oxidation rate by 51 and 47%, respectively, and lengthened the lag phase of low-density lipoprotein oxidation by 2.6 and 1.8 times, respectively, which confirmed their antioxidant potency.

AIM To study the impact of cold waves on disease course, hemodynamics, lipid and carbohydrate metabolisms, oxidative stress, and blood rheological properties in patients with cardiovascular diseases (CVD). SUBJECTS AND METHODS 24 men and 36 women (their mean age was 62.9±9.7 years) were examined; coronary heart disease (CHD) and hypertension were present in 40 and 95% of the patients, respectively; selected therapy remained unchanged throughout the entire period. The investigators measured blood pressure and pulse wave velocity (PWV), carried out biochemical blood tests, estimated plasma oxidized low-density lipoproteins (oxLDL) and malondialdehyde (MDA) and erythrocyte superoxide dismutase (SOD) activity, calculated a MDA/SOD ratio, determined blood viscosity; as well as assessed quality of life using a visual analogue scale (VAS) and a specially developed questionnaire. RESULTS Female sex, CHD, type 2 diabetes mellitus (DM-2) were independent predictors of cardiovascular events (CVEs) in the frost period. The persons who had experienced CVEs in frost had higher baseline PWV. CVEs, such as hypertensive crisis, emergency calls, cardiac arrhythmias, and the larger number of adverse reactions, were more commonly recorded in frost. There was an increase in blood glucose levels, a decrease in oxLDL, a rise in η2/η1, and a reduction in plasma viscosity during frost and elevated glycation end product levels at visit 2. Conclusion. The cold wave is associated with the larger number of CVEs in some patients with CVD during selected therapy. CHD, DM-2, female sex are independent predictors of CVE in patients with CVD during the winter period. In this period, there were increases in the levels of glucose, glycation end products, and erythrocyte aggregation, and a reduction in plasma viscosity.

This study investigated the effects of peptide apelin-12 (H-Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Met-Pro-Phe-OH, A12) and its novel structural analog (H-(NαMe)Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-OH, AI) on myocardial antioxidant enzyme activities, lipid peroxidation, and reactive oxygen species formation in ex vivo and in vivo models of myocardial ischemia/reperfusion (I/R) injury. Isolated working rat hearts were subjected to global ischemia and reperfusion. Infusion of 140 μM A12 or AI before global ischemia improved cardiac function recovery; increased the activity of Cu,Zn superoxide dismutase (Cu,Zn SOD), catalase (CAT), and glutathione peroxidase (GSH-Px); decreased malondialdehyde (MDA) content in reperfused heart; and reduced the formation of hydroxyl radical adduct of the spin trap 5,5-dimethyl-1-pyrroline-N-oxide in the myocardial effluent during early reperfusion compared with these indices in control. Anesthetized open-chest rats were subjected to the left anterior descending coronary artery occlusion and coronary reperfusion. Peptide A12 or its analog AI was injected intravenously at the onset of reperfusion at a dose of 0.35 μmol/kg. Treatment with A12 or AI significantly limited infarct size and reduced the activity of lactate dehydrogenase and creatine kinase MB isoenzyme in blood plasma at the end of reperfusion compared with control. These effects were accompanied by complete recovery of Cu,Zn SOD, CAT, and GSH-Px activities; and decrease in MDA content in the area at risk by the end of reperfusion. The study concluded that C-terminal fragment of native peptide apelin-12 and its synthesized analog is involved in the upregulation of cardiac antioxidant defense systems and attenuation of lipid peroxidation in myocardial I/R injury.

Aim. To evaluate the drug implied to improve the metabolic resistance to stress (adaptogen), Qudesan®, on its influence on cardiovascular system, psychological status and life quality of patients with average to high cardiovascular risk in the extreme climatic conditions (the summer heat).Material and methods. We included 60 patients; for 30 of those the Qudesan® 40 gtts. qd was added to standard drug therapy; other 30 patients were controls. We measured office BP, potassium and sodium concentrations; malonic dialdehyde (MDA), superoxidedysmutase (SOD) in erythrocytes. Then the relation of MDA/SOD was calculate. Patients also completed the questionnaire made up for this study. Results. In the Qudesan® group during the heat period we found lowering of SBP (А -13,8 mmHg, p=0,02), DBP (А -4,5 mmHg, p=0,05) and PWV (А -0,8 m/s, p=0,05) absent in the control. Also in Qudesan® group the concentration of sodium starts to increase during the heat period (А +1,0 mM/l, p=0,008). This increase becomes significant by september (А +1,7 mM/l, p=0,008) and is probably adaptive. The level of MDA (p<0,05) and MDA/SOD relation, the signs of "antioxydant potential", in blood were increasing significantly during the summer heat only in control group. The complaints on heart rhythm disorders (p=0,04) and on CHF worsening (p=0,09) after the end of heat period were more common in control group. That is the Qudesan® shows adaptogenic effect and can be used to improve adaptability during the heat period and its switching to cloder time in patients with compensated CVD.