OMEGA-3 POLYUNSATURATED FATTY ACIDS NORMALIZE THE FUNCTION OF MITOCHONDRIA, ACTIVITY OF ENZYMES OF PROOXIDANT-ANTIOXIDANT SYSTEM AND THE EXPRESSION OF CYTOCHROME Р450 2Е1 AFTER ISOPROTERENOLINDUCED MYOCARDIAL INJURY.

We have studied the influence of dietary ω-3 polyunsaturated fatty acids (ω-3 PUFA) on the functioning of subsarcolemmal and interfibrillar mitochondrial fractions of rat myocardium, changes in expression of cytochrome P450 (CYP2E1) and the activity of enzymes of prooxidant-antioxidant system after isoproterenol-induced myocardial injury. It has been found that in vivo administration of ω-3 PUFA (Epadol 0.1 ml/100 gr of weight for 4 weeks) significantly reduced the swelling of subsarcolemmal and interfibrillar mitochondrial fractions by 65.52% 54.84% respectively, pointing for a decrease of damage of the mitochondrial function evoked by in vivo administration of isoproterenol. In vivo administration of ω-3 PUFAs prevents a decrease in the activity of antioxidant enzymes catalase and superoxide dismutase (2.65 and 7.1- fold, respectively) after isoproterenol-induced myocardial injury. We suggest that the development of oxidative stress after isoproterenol-induced myocardial injury can be caused by a significant increase in the expression of cytochrome P450 2E1 (73.3%), and administration of ω-3 PUFAs prevents such changes.

[The influence of dietary omega-3 polyunsaturated fatty acids on functional parameters of myocardial mitochondria during isoproterenol-induced heart injury].

We have studied the functional parameters of mitochondria from hearts after isopreterenol-induced injury (two subcutaneous injections of isopreterenol at the dose 60 mg/kg/day). We investigated the influence of dietary omega-3 polyunsaturated fatty acids (omega-3 PUFAs) administered to rats (Epadol, 0.1 mg/100 gr of weight for 4 weeks) on these parameters. Isoproterenol-induced heart injury leads to a decreased parameters of respiration of isolated mitochondria in the presence of succinate. Administration of omega-3 PUFAs significantly restored the respiration rate of mitochondria: the state 3 respiration was increased by 70.12%, the state 4 by 39.87% and the respiratory control ratio by 45.19% compared to the corresponding parameters of experimental group. Also, it was shown the ability of omega-3 PUFAs to decrease mitochondria swelling (by 60%) in nominally free calcium solution. The results of the study indicate that omega-3 PUFAs improve the altered functions of the heart mitochondria evoked by isoproterenol-induced injury.

[Correction of cardiodynamic disorders in experimental diabetes by omega-3 polyunsaturated fatty acids].

In experiments on rat hearts in vivo with the system for pressure-volume registration "Millar Instruments" cardiodynamic disorders were studied in experimental diabetes for their correction with omega-3 polyunsaturated fatty acids (PUFAs). The application of omega-3 PUFAs in animals with diabetes may improve cardiodynamic parameters--pump and diastolic function.

[Study of the impact of omega-3 PUFA on fatty acid composition of heart, respiration and swelling of mitochondria of the heart in diabetes].

We studied the influence of omega-3 polyunsaturated fatty acids (PUFAs) on respiration, swelling of rat heart mitochondria and changes in rat heart fatty acid composition in tissue homogenate in rats with streptozotocin induced diabetes mellitus (diabetes), which was induced by single intraperitoneal administration of 55 mg/kg streptozotocin. We found that application of these acids increased parameters of active mitochondrial respiration V3 at 63.7%, controlled breathing V4 at 30.7% and the rate of phosphorylation by 18.9% in animals with experimental diabetes. We proved their ability to reduce swelling of mitochondria in heart at streptozotocin induced diabetes. In addition, we established changes of fatty acid composition of cell membranes in hearts under diabetic conditions with omega-3 PUFAs influence. The obtained results allow to conclude that the omega-3 PUFA have a positive effect on functional parameters of mitochondria due to stabilization cell membranes of rat heart with diabetes.

[Correction of lipid peroxidation and antioxidant system disorders by bioflavonoids during modeling of cholesterol atherosclerosis in rabbits].

We have studied the influence of bioflavonoids (quercetin, corvitin) on lipid peroxidation and antioxidant enzymes in the modeling of cholesterol atherosclerosis in rabbits. It has been shown that simultaneous administration of the quercetin derivative corvitin suppressed lipid peroxidation. We showed that under hypercholesterolemia, the concentration of malone dialdehyde in myocardial tissue in rabbits is significantly increased, while administration of bioflavonoids decreased the concentration of malone dialdehyde by 38.3%. Furthermore, corvitin caused activating effects on antioxidant enzymes superoxide dismutase and catalase in cardiac tissue. Our data suggest that bioflavonoids are able to suppress lipid peroxidation and prevent the decrease ofantioxidant enzymes activity in rabbits with cholesterol-rich diet induced atherosclerosis.

[Omega-3 polyunsaturated fatty acids stimulate the expression of PPAR target genes].

In experiments on isolated neonatal cardiomyocytes and hearts of adult rats we investigated the influence of polyunsaturated fatty acids (PUFA) on expression of two peroxisome proliferator-activated receptor (PPAR) target genes--fatty acid transport protein (FATP) and interleukin-1 receptor antagonist (IL-1ra). We determined that cell membranes of adult rats heart and cardiomyocytes of neonatal rats which were born by females fed with omega-3 PUFA for 4 weeks, contain more omega-3 PUFA (alpha-linolenic and docosahexaenoic acids) in comparison with the control. It was shown that omega-3 PUFA elevated FATP and IL-1ra mRNA expression in 2.25 (P = 0.07) and 8.4 (P < 0.00001) folds correspondingly in adult rats tissues. In isolated cardiomyocytes, the mRNA expression of FATP and IL-1ra were augmented 2.5 folds (P = 0.22) and 8.1 folds (P < 0.00001), accordingly. Our data show that omega-3 PUFA stimulate PPAR target genes expression and allow to permit genetic mechanisms in cardioprotective effects of omega-3 PUFA.

[Cardioprotective effects of activation of ATP-sensitive potassium channels in experiments in vivo: influence on blood biochemical parameters following ischemia-reperfusion of the myocardium].

In experiments on the anaesthetized dogs with modeling of experimental ischemia (90 min) and reperfusion (180 min), the participation of biochemical processes in the cardioprotective effect of the preischemic activation of ATP-sensitive potassium (KATP) channels caused by intravenous introduction of flokalin, a new fluorine-containing opener of these channels was shown. Flokalin was introduced in a dose 0.1 mg/kg of animal body weight which practically did not change the parameters of hemodynamic in normoxia. Thus, the experiments investigating the influence offlokalin on changes of biochemical parameters of arterial blood during ischemia-reperfusion of myocardium showed certain features of ischemia-reperfusion syndrome development during stimulation of K(ATP) channels. The analysis of biochemical parameters of blood showed that flokalin suppressed free radical reactions and had antioxidant properties: reduced quantity of H2O2 and NO3- (the last can interpreted as a reduction in peroxynitrites formation), prevented the decline of catalase and superoxide dismutase activity. Practically constant content of low-molecular nitrosothiols in blood during all duration of experiment and increase of NO2-level during reperfusion may indicate on intact functions of the NO system and protective influence of flokalin during ischemia-reperfusion of myocardium. Practically unchanged content of inorganic phosphorus and uric acid in blood during ischemia- reperfusion under conditions of preischemic introduction of flokalin indicates the prevention of ATP degradation and fomation of both superoxide anion by xanthinoxidase and peroxynitrite by it interaction with nitric oxide. All mentioned properties of flokalin related to the changes of biochemical parameters of arterial blood, together with the changes of parameters of hemodynamics, result in diminishment of infarct size of myocardium after ischemia-reperfusion by 37% versus control experiments. K(ATP) channels, flokalin, ischemia-reperfusion, free radikaly, NO system.

[The effects of alpha-linolenic acid on the functioning of the isolated heart during acute myocardial ischemia/reperfusion].

Many studies indicate that dietary omega-3 polyunsaturated fatty acids (PUFAs) have the cardioprotective properties. But majority of experiments were carried out with using omega-3 PUFAs from marine fish oil. The purpose of this study was to determine effects of the plant-derived omega-3 PUFA (alpha-linolenic acid (a-LA) on postischemic myocardial dysfunction, lipid peroxidation and antioxidant enzymes activity. Male Wistar rats (250-300 g) were divided into 4 groups (n = 10-12 each). In control group (1) were intact rats. The hearts from 2-nd group of animal were exposed to 20 min of global ischemia followed by 40 min reperfusion according to the Langendorff technique. The 3-rd and 4-th groups of animal received of the plant-derived oil (a-LA), which is a precursor of eicosapentaenoic acid and was used as a dietary supplement in dose 0.1 mg/kg per day for 4 weeks. The hearts from 4-th group of animal were also exposed to ischemia/ reperfusion. Analysis of myocardial phospholipid fatty acid content showed that consumption of the plant-derived 6-LA for 4 weeks changes fatty acid profile through incorporation of b-LA in cell membranes. It also reduced content of omega-6 PUFAs in membrane phospholipids. In 3-rd group content of a-LA and EPA were increased by 1.5- and 3.5-times, respectively, whereas content of AA was reduced by 1.7-times. The development of ischemia/ reperfusion in 2-nd group caused increase of free AA content in heart tissue by 3.5-times, whereas in 4-th group this increase was only by 1.4-time. Ischemia/reperfusion of the isolated rat heart in 4-th group was accompanied by reduced leukotriene C4 and thromboxane B2 production in 3-times and 1.9-times, respectively in comparison to 2-nd group. The time of myocardial function recovery after ischemia (heart rate, left ventricular development pressure), was shorter compare to 2-nd group. Also in 4th group end-diastolic pressure and coronary perfusion pressure during reperfusion period were significantly lower. Dietary omega-3 PUFAs resulted in remarkable decrease of reperfusion arrhythmias in 4-th group (in 3.8-times) and limited the oxidative stress through decrease free radical and lipid peroxidation production. In this group of animals the activity of antioxidant enzymes (superoxide dismutase and catalase) after ischemia/reperfusion were higher than in 2-nd group. We suggest that dietary supplement of the plant-derived alpha-LA for 4 weeks have cardioprotective effects similar to the effects of fish oil.

[Phospholipid membrane modification as a protection factor of the myocardium during stress injury].

In experiments on the isolated rat hearts we investigated the influence of phospholipid membrane modification by omega-3 polyunsaturated fatty acids (PUFAs) on the heart reactivity to adrenergic influences, myocardial ultrastructure and peroxidation processes under the immobilization stress. It was shown that omega-3 PUFAs reduced ultrastructural changes in the heart, limited lipid peroxidation and attenuated inotropic response of the heart to exogenous norepinephrine.

[The effects of omega-3 polyunsaturated fatty acids on lipid peroxidation].

The aim of this study was to evaluate the effects of a diet supplemented with omega-3 polyunsaturated fatty acids (PUFAs) (plant-derived alpha-linolenic acid and eicosapentaenoic and docosahexaenoic acids with alpha-tocopherol (product "Tekom") on the myocardial phospholipid fatty acids composition, lipid peroxidation and activity antioxidant enzymes--superoxide dismutase and catalase in myocardial tissue in control and after ischemia/reperfusion of isolated working rat hearts. Inclusion of omega-3 PUFAs into the animals' diet within 4 weeks demonstrated that alpha-linolenic acid and "Tekom" increased omega-3 polyunsaturated fatty acids content in cardiomyocytes membranes and limited lipid peroxidation (decreased content of congugates of dienes and malone dialdehyde, reduced hemiluminescence of myocardial tissue). Additionally omega-3 PUFAs caused the beneficial effects on activity of antioxidant enzymes in cardiac tissue (increased superoxide dismutase and catalase activity).

[Effect of modification in cell membrane fatty acid composition on adrenergic cardiac and vascular reactivity]. / Vplyv modyfikatsiï zhyrnokyslotnoho skladu klitynnykh membran na adrenerhichnu reaktyvnist' sertsia ta sudyn.

The work is dedicated to examination of the effect an omega-3 polyunsaturated fatty acids (PUFA) on vascular and cardiac reactivity in intact animals. In experiments on isolated perfused rat hearts and isolated rings of rat aorta it was shown that reactivity in rats with modified membranes was lesser than in control animals after adding norepinephrine in raising concentrations. Use of omega-3 PUFA resulted in the decrease of omega-6 PUFAs (arachidonic acid (AA)) content, while omega-3 PUFAs (EPA, DHA) content in cardiomyocytes membranes increased. Besides that it was shown that after omega-3 PUFA enriched diet NO3- content increased in cardiac tissues and blood.

[Effect of modification in fatty acid composition of membrane phospholipids on reaction of isolated heart in acute ischemia-reperfusion]. / Vplyv modyfikatsiï zhyrnokyslotnoho skladu fosfolipidiv membran na reaktsiiu izol'ovanoho sertsia pry hostrii ishemiï-reperfuziï.

The aim of this study was to evaluate the effects of a diet supplemented with omega-3 polyunsaturated fatty acids (eicosapentaenoic and docosahexaenoic) and tocopherol, which are the base of a preparation "Tekom", on a composition of myocardial phospholipid fatty acids, as well as on the metabolism of eicosanoids, free radical processes and the contractility of isolated working heart in rats at ischemia/reperfusion. Added to the diet within 4 weeks, "Tekom" induced an increase in the content of omega-3 polyunsaturated fatty acids in membranes of cardiomyocytes, a decrease in vasoactive metabolites of arachidonic acid and limitation of free radical processes. "Tekom" inhibited cardiac arrhythmias in the isolated working hearts of rats and improved the cardiac pump function at ischemia/reperfusion.

[Cardioprotective effects of a new fluorine-containing synthetic activator of ATP-dependent potassium channels]. / Doslidzhennia kardioprotektornykh efektiv novoho ftormisnoho aktyvatora ATF-zalezhnykh kaliievykh kanaliv.

Effects of PF-10 the new fluorine-containing activator of ATP-dependent K-channels were investigated on the guinea-pig isolated heart. PF-10 enhanced myocardial contractility and decreased coronary vessels resistance in a dose-dependent manner. Low doses (10 mM/L, 1 mM/L) of PF-10 attenuates of the spontaneous alterations of heart rate, while high doses (0.1 mM/L) leds to these alterations. Previous activation of ATP-dependent K-channels by PF-10 has a cardioprotective effect during ischemia-reperfusion which a similar to the well-known phenomenon of ischemic preconditioning.