[Role of adipokines and nonesterified fatty acids in the development of insulin resistance].

The purpose of the study was to reveal a possible role of adipokines, biologically active adipose tissue proteins (leptin and adiponectin) and nonesterified fatty acids in generating insulin resistance (IR). One hundred and fifty-seven patients (90 females and 67 males) aged 57.5±9.2 years were enrolled in the study. According to the HOMA index for IR, the patients were divided into 3 equal groups. The examinees with a high HOMA index were found to have elevated levels of fatty acids, leptin and decreased concentrations of adiponectin. At the same time according to the linear regression analysis, all these indices are its independent determinants. However, analysis of the data in the groups of patients with different body weight revealed that the increased concentrations of fatty acids and leptin may play a role in the development of IR in subjects with obesity while the higher level of fatty acids and lower adiponectin may be involved in patients without noticeable obesity. Thus, it may be assumed that leptin, adiponectin and nonesterified fatty acids may affect the development of IR; however, their contribution depends on the degree of adiposity.

[Adiponectin: lowering in metabolic syndrome and independent relation to hypertriglyceridemia].

Aim of the study was to elucidate possible role of adiponectin in development of clinico-metabolic derangements in metabolic syndrome (MS). We examined 35 men and 45 women (mean age 58.0+/-8.8 years). Adiponectin level was significantly lower (p<0.01) in patients with MS (5.8+/-4.6) compared with subjects without MS (9.2+/-5.3 mkg/ml). Body mass index (BMI), waist circumference (WC), index of insulin resistance , levels of glucose, insulin, free fatty acids (FFA), triglycerides (TG) were lower in 3rd tertile of distribution of adiponectin blood content compared with 1st tertile. Significant negative correlations were found between adiponectin content and BMI (r=-0.36), WC (r=-0.34), index (r=-0.31), level of diastolic arterial pressure (r=-0.34), concentrations of glucose (r=-0.24), insulin (r=-0.26), FFA (r=-0.24), TG (r=-0.45), uric acid (r=-0.29). Correlation between adiponectin and level of high density lipoprotein cholesterol was positive (I=0.26). However after adjustment for MI, sex, and age adiponectin content correlated significantly only with concentration of TG (r=-0.27) and diastolic arterial pressure (r=-0.26). Regression analysis revealed independent from factors presented above role of adiponectin in determination of blood level of TG (beta=-0.30, p=0.02).

Antioxidative activity of high density lipoproteins in vivo.

The present study consists of experimental and clinical investigations. It was shown that a single intravenous injection of a large dose of human HDL3 (200 mg protein) to rabbits with induced hypercholesterolemia (plasma cholesterol 500-700 mg/dl) was accompanied by a significant elevation of plasma HDL and led to a decrease (P < 0.05) of conjugated dienes and trienes by 20-30% after 6 h. Conjugated dienes remained stable for 24 h after HDL administration. In the clinical investigations a weak but statistically significant negative correlation (r = 0.262; P = 0.006) between HDL cholesterol and the content of conjugated dienes in the plasma of a total group of healthy subjects and patients with coronary heart disease (CHD) was found. The data allowed us to conclude that, in addition to other antioxidative systems, HDL also take part in the protection of plasma lipids from peroxidation.

[Lipid peroxidation as a mechanism for the regulation of platelet aggregation activity]. / Perekisnoe okislenie lipidov kak mekhanizm reguliatsii agregatsionnoi aktivnosti trombotsitov.

The paper deals with the role of free radical lipid oxidation in the mechanisms of platelet activation. The findings suggest that lipid peroxidation metabolites (primary and secondary) are able to produce regulatory effects mediated by membrane arrangement on platelet aggregatory properties. At the same time the higher levels of conjugated dienes can induce platelet aggregation in unstable angina pectoris. This expands the current concepts of the mechanisms of abnormal platelet activation and allows it to be classified as a particular system.

[Antioxidant activity of high density lipoproteins in vivo]. / Antioksidantnaia aktivnost' lipoproteidov vysokoi plotnosti in vivo.

The paper deals with antioxidant effect of high density lipoproteins (HDL) in vivo. The effect of intravenous injection of large-dose HDL3 (200 mg protein), isolated from human plasma to rabbits with experimental hypercholesterolemia, on the content of primary products of lipid peroxidation in rabbit blood, the correlation between HDL cholesterol level and the content of lipid peroxide products in blood plasma of healthy persons and patients with IHD were studied. Intravenous injection of HDL3 to rabbits with experimental hypercholesterolemia has been shown to lead in 6 hr to a 24-hr significant (p < 0.01) decrease of conjugated dienes and trienes. The existence of negative correlation between HDL-cholesterol level and the content of conjugated dienes in blood plasma of healthy persons (N = 47) and patients with IHD (n = 64) is revealed. Basing on the data obtained conclusion of universal character of protective antiatherogenic effect of HDL is drawn.

[Effect of essential phospholipids on intensity of lipid peroxidation in the myocardium in experimental post-hypoxic reoxygenation]. / Vliianie éssentsial'nykh fosfolipidov na intensivnost lipoperoksidatsii v miokarde pri éksperimental'noi postgipoksicheskoi reoksigenatsii.

Correction of the lipid peroxidation rate using essential phospholipids was studied. The phospholipids were used in protection of heart tissue in experimental posthypoxic reoxygenation. Administration of essential phospholipids into the rats during myocardium reoxygenation led to an increase in activity of superoxide dismutase. The drugs containing essential phospholipids may be used in clinical practice for treatment of the impairments when elevated lipid peroxidation occurred.

[The role of cholesterol in activating lipid peroxidation in platelets]. / Rol' kholesterina v aktivatsii perekisnogo okiseniia lipidov v trombotsitakh.

The relationship between the cholesterol (Ch) content and the concentration of lipid peroxidation (LPO) products in activated platelets and the effect of these parameters on the structure-function characteristics of platelet membranes were studied. It was found that esterified Ch activates free radical processes occurring in platelets. Nonesterified Ch does not induce the production of primary products of LPO (dienoic conjugates) but promotes the accumulation of a secondary LPO metabolite, malonic dialdehyde, this reaction being mediated via indirect mechanisms. The higher (in comparison with normal) orderliness and orientation of membranes in platelets reflect the increase in the concentration of dienoic conjugates and nonesterified Ch. The observed differences in the aggregability of platelets are due to the changes in the Ch content as well as to the "rigidity" of blood platelets.

[A comparative analysis of two methods of determining superoxide dismutase activity]. / Sravnitel'nyi analiz dvukh metodov opredeleniiaaktivnosti superoksiddismutazy.

Two methods for measuring superoxide dismutase activities are compared, that developed by Nishikimi et al. and by Mistra and Fridovich. The results of both methods showed good correlation in studies of dog red cells (r = +0.999, p less than 0.001) and of intact rat heart tissue (r = +0.996, p less than 0.001).

[Effects of ubinon-9, a synthetic antioxidant, on intensity of lipid peroxidation in blood platelets and plasma of patients with ischemic heart disease]. / Vliianie sinteticheskogo antioksidanta ubinona-9 na intensivenost' perekisnogo okisleniia lipidov v thrombotsitakh i plazme krovi bol'nykh ishemicheskoi bolezn'iu serdtsa.

The antioxidant ubinon-9 was tested for its effects on platelet and plasma lipid peroxidation parameters in patients with acute ischemic heart diseases. The use of ubinon-9 in the multimodality therapy of patients with ischemic heart disease was shown to result in a significant decrease in lipid peroxidation intensity by enhancing superoxide dismutase activity in the platelets and plasma from the patients. Ubinon-9 equally prevented lipid peroxidation activation during enzymatic and nonenzymatic induction in the platelets of patients with unstable angina or acute myocardial infarction. Unlike a daily dose of 30 mg, 90 mg a day is a more effective dose in reducing platelet and plasma lipid peroxidation parameters. One may suggest that addition of ubinon-9 into the routine treatment regimen allows the therapy for acute ischemic heart disease to be optimize.

[Status of thrombocyte membranes and lipid peroxidation in patients with unstable stenocardia]. / Sostoianie membran i osobennosti perekisnogo okisleniia lipidov trombotsitov u bol'nykh s nestabil'noi stenokardiei.

Platelet and plasma lipid peroxidation (LPO) activity, and possible effect of LPO products on platelet membrane structure were examined in patients with unstable angina, an acute form of coronary disease. All parameters of LPO were increased both in the platelets and the plasma. It was demonstrated by spinning probes that platelet membrane S degree of order was increased significantly, an evidence of increased microviscosity, in patients with unstable angina. There also was a positive correlation between the S value and the level of LPO products. It is suggested that membrane disorders, in which CHD-related platelet hyperreactivity is rooted, may in part be due to PLO activation in the platelets.

[Various indices of lipid peroxidation in thrombocytes of patients with ischemic heart disease]. / Nekotorye pokazateli perekisnogo okisleniia lipidov trombotsitov u bol'nykh ishemicheskoi bolezn'iu serdtsa.

Interaction between lipid peroxidation activation and the antioxidant system was studied in thrombocytes of patients with cardiovascular pathology. Positive correlation between superoxide dismutase activity and malonic dialdehyde content was found in healthy persons, while in patients with unstable stenocardia and acute myocardial infarction an inversion of the correlation parameters occurred. The data obtained may be used for prognosis of heart ischemic disease development.