[Induction of nitrosative stress in mitochondria of rats hearts in experimental ischemia-reperfusion of the brain and its correction by ecdysterone].

On the model of focal ischemia-reperfusion of the brain investigated the induction of nitrosative stress in mitochondria of rats hearts and possible mechanisms of protective action of ecdysterone. It is shown that focal ischemia-reperfusion of the brain induced in myocardial mitochondria the activation of constitutive and inducible de novo synthesis of NO by oxidation of L-arginine and not oxidative synthesis of NO through the recovery of oxidized stable metabolites of NO. Strong evidence of induction of nitrosative stress in heart mitochondria by focal ischemia-reperfusion of the brain, was a significant increase in mitochondrial pool of nitrate- and nitrite-anions and pools of nitrosothiols, that is proof of the formation and decay of peroxynitrite--a key marker of nitrosative stress. Also was observed increase in heart mitochondria by focal ischemia-reperfusion of the brain, content key regulator of de novo synthesis of NO-hydrogen sulfide and activity of inducible arginase II and, as a result, the pool of carbamide, which is also a regulator of the synthesis of NO. Previous introduction for animals herbal extract Serratsula coronata, enriched ecdysterone, reduces induction nitrosative stress in mitochondria of rats hearts under conditions of focal ischemia-reperfusion of the brain.

[Magnetic-laser influence on the system of nitric oxide and contractile activity of smooth muscles of rat aorta under hypertension].

The study was conducted on three groups of rats: Group I included Wistar rats with normal blood pressure (first control group); group II - rats with genetically determined hypertension (second control group); group Ill - rats with genetically determined hypertension under the influence ofmagnetic-laser power (study group). For the low-intensively magnetic-laser influence (MLI) we have used device MIT-MT, Ukraine, which was designed for the treatment of low-frequency magnetic field using optical flow blue and red ranges of spectrum. The MLI duration was 15 minutes for the blue range, and 25 minutes for the red one. Biochemical studies included the determination of the activity of isoenzymes of NO-synthase: constitutive (cNOS) and inducible (iNOS), the content of free hemoglobin, stable metabolites of NO, namely nitrite - (NO2(-)) and nitrate - (NO3(-)) anions, resistance to acid hemolysis of red blood cells. The contractile activity of smooth muscles of the aorta was measured. We found that magnetic-laser exposure of rats with genetically determined hypertension in the red (630 nm) and blue (470 nm wavelength) optical range even after a single session leads to an increased synthesis of nitric oxide in the blood plasma. Our data sindicate that the most effective in the intensification of endogenous nitric oxide (increase of NO2(-) and reduction of NO3(-)) and endothelium-dependent responses of aorta in rats with genetically determined hypertension was a ten-day course of the magnetic-laser exposure in the optical flow of the blue spectral range. Also, after 10 sessions of magnetic-laser exposure in rats from the above specified spectrum a stabilization of erythrocyte membranes was observed.

[Effects of uncoupling proteins on nitric oxide synthesis and oxidative stress development in ishemia-reperfusion of old rat hearts].

Genipin is aglycone of geniposide, one of the active compounds of Gardenia gasminoides Ellis. The gardenia fruit extract has been used in traditional Chinese medicine to relieve the symptoms of type 2 diabetes that is accompanied with extensive oxidative stress and endothelial dysfunction of NO production. Besides, genipin was shown to inhibit UCP-depended proton leak through the inner mitochondrial membrane that leads to increased membrane potential and ATP production. We studied the effects of genipin at ischemia/reperfusion-induced oxidative stress and activity of NOS isozymes using Langendorfperfused old rat heart model. Ischemia/reperfusion is well-known oxidative agent, and showed significant increasing of superoxide radical, hydrogen peroxide and hydroxyl radical. Genipin application in doze 10-5 mol/L for 15 min before prolonged ischemia exerted powerful antiradical and antilipoperoxidative effects. Heart ischemia/reperfusion was supported with peroxynitrite generation and nitrozative stress. We demonstrated the inhibitory property of genipin on INOS expression that possibly occurs via protein kinase A inhibition and stabilization of I-kappaB-NF-kappaB complex. Genipin stimulated cNOS activity seemingly activating PI3K/Akt signaling pathway. Although, post-ischemic recovery ofcardiodynamic parameters of old rat hearts were depressed due to "switching off" the NO production by inducible NOS which is important in early period of reperfusion. Thus, we conclude that genipin is powerfull antioxidant and posses insulin-like activity due to its property of managing the NO production at intracellular signal transduction cascade level.

[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.

[Modulating effect of Serratula coronata extract on nitric oxide metabolism in the aorta tissues of rats in lead intoxication].

Vasotoxic effect of prolonged lead exposures and the efficiency of vasoprotective effect of S. coronata extract per os addition is estimated in rats aorta It is established that lead in aorta causes a significant increase in reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation by increasing the activity of inducible isoform of NO-synthase (iNOS). The use of S. coronata extracts promotes ROS and RNS production decreasing by normalyzing the iNOS activity in exposures to lead acetate rat aortas.

[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.

[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 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.