Cholesterol enriched diet suppresses ATF6 and PERK and upregulates the IRE1 pathways of the unfolded protein response in spontaneously hypertensive rats: Relevance to pathophysiology of atherosclerosis in the setting of hypertension.

Many studies have been dedicated to hypertension and hypercholesterolemia, as they are the primary conditions that influence the unfolded protein response (UPR). However, the concurrent effects of these two factors are unknown. Our research used spontaneously hypertensive rats (SHR) fed a cholesterol enriched diet (CED) as model of atherosclerosis formation to discover what effect the simultaneous actions of hypertension and hypercholesterolemia have on the UPR.

Dietary Omega-3 Polyunsaturated Fatty Acids Alter Fatty Acid Composition of Lipids and CYP2E1 Expression in Rat Liver Tissue.

Omega-3 polyunsaturated fatty acids (PUFAs) are used for the treatment and prevention of numerous pathologies in humans. As recently found, PUFAs play significantly protective roles in liver, cardiovascular system and kidney. They also are widely used in total parenteral nutrition.

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.

[The changes in the activity of tripeptidyl peptidase II in experimental atherosclerosis and hypertension].

The changes in the activity of intracellular proteolytic systems are important mechanisms in the damage of blood vessels walls and arterial hypertension. Tripeptidyl peptidase II (TPP II) is one of the giant intracellular protease that is still poorly known. It fulfils hydrolysis of peptides, coming from proteasomal proteolysis.

[Effect of quercetin on proteasome activity in the aorta and heart tissues of spontaneously hypertensive rats].

To determine the role of proteasome proteolysis in the pathogenesis of hypertension, we have studied the proteolytic activity of the proteasome in the aorta and heart tissues of rats with spontaneous hypertension (line SHR), and used quercetin, the drug that can inhibit the activity of this multicatalytic complex. In the aorta of SHR, the activities of the proteasome were not significantly different from that observed in Wistar rats. At the same time, in the heart tissues the trypsin-like (at 40%, P > 0.

[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.

Omega-3 polyunsaturated fatty acid-enriched diet differentially protects two subpopulations of myocardial mitochondria against Ca(2+)-induced injury.

Omega-3 polyunsaturated fatty acids (PUFA) confer protection against myocardial injury after ischemia-reperfusion. There are two subfractions of mitochondria located in different regions of the cell: subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM). The present study explored possible differences between Ca(2+)-induced mitochondrial swelling in rat SSM and IFM fractions under control conditions (control group [CG]) and after dietary supplementation with omega-3 PUFA (experimental group [EG]).

[Biochemical mechanisms of the cardioprotective effect of the K(ATP) channels opener flocalin (medicinal form) in ischemia-reperfusion of myocardium].

In experiments on the anaesthetized dogs with modeling of experimental ischemia (90 min) and reperfusion (180 min) of myocardium it was investigated changes of biochemical processes in arterial blood at intragastric introduction of medicinal form (tablets) of flocalin (the fluorine-containing opener of ATP-sensitive potassium channels) in a dose 2,2 mg/kg. The data analysis allowed to define a few possible mechanisms of cardioprotective action offlocalin, which prevented the opening of a mitochondrial permeability transition pore (MPTP) and inhibition of apoptosis induced by it. They consist, from one side, in activating of the constitutive de novo biosynthesis of nitric oxide by cNOS, from other side, in suppression of inducible nitric oxide de novo synthesis by iNOS in such way to prevent the formation of toxic peroxynitrite by co-operation of surplus nitric oxide with superoxide anion, thereby limits the generation of toxic active forms of nitrogen (*NO2) and oxygen (*OH).

[Influence of flocalin on development of apoptosis and necrosis at anoxia-reoxygenation of culture rats neonatal cardiomyocytes].

The influence of the new cardioprotector flocalin was investigated on the culture of rat's neonatal cardiomyocytes during anoxia-reoxygenation modelling. The mechanisms of apoptosis and necrosis were investigated under influence of ATP-sensitive potassium (K(ATP)) channels activation and in conditions of blocking of the L-type calcium (VGCCs) channels. Flocalin was added in the culture medium in the dose 5 and 20 microM at 2 minutes before anoxia (30 minutes) and following reoxygenation (60 minutes).

[The influence of activation of the ATP-sensitive potassium channels by flocalin on the function of the cardiovascular system].

In experiments on the anaesthetized dogs the influence of a new fluorine-containing opener of ATP-sensitive potassium (K(ATP)) channels flocalin on the cardiohemodynamic of great animals in vivo was studied. Flocalin introduced intravenously in doses 0.01 - 1.

[T(-786) --> C-polymorphism of the endothelial nitric oxide synthase promoter gene (eNOS) and exercise performance in sport].

Given the significant impact of the T(-786) --> C-polymorphism of the eNOS gene in the process of adaptation to physical stress, we aimed to investigate the effect of this polymorphism on physical performance in sportsmen and establish the possibility of its use as a marker of predisposition to the sport. DNA of 516 people, of which 195 qualified athletes and 321 people who had no experience of regular exercise was investigated. The frequency of genotypes and alleles of the T(-786) --> C-polymorphism of the eNOS gene in groups of athletes of different sports, the distribution of genotypes and alleles among athletes and those who are not involved in sports were studied.

Genetic predisposition to essential hypertension in children: analysis of 17 single nucleotide polymorphisms.

Study of 17 single nucleotide polymorphisms has been performed to determine the factors of genetic predisposition to essential hypertension. Polymerase chain reaction (PCR) with subsequent analysis of restriction fragment length, allele specific PCR or real-time PCR was used for genotyping of 17 single nucleotide polymorphisms in 14 genes in 145 children with essential hypertension and 144 healthy persons with following complex multivariate statistical analysis. Two single nucleotide polymorphisms--MMP9 (C(-1562) --> T) and NOS3 (Glu298 --> Asp)--rs3918242 and rs1799983--were shown to represent the main independent effects with the highest predictive potential (77.

[New fluorine-containing openers of ATP-sensitive potassium channels flokalin and tioflokalin inhibit calcium-induced mitochondrial pore opening in rat hearts].

In experiments in vitro on the mitochondria isolated from the rat's heart we studied the effects of the openers of ATP-sensitive potassium channels (K(ATP)-channels), flocalin and tioflocalin, on the calcium-induced mitochondrial pore (MPTP) opening. Flocalin and tioflocalin caused moderate Ca(2+)-independent mitochondria swelling, which was prevented by a specific inhibitor of 5-hydroxydecanoate. This allowed to identify these compounds as mitochondrial K(ATP)-channels openers.

Effects of fluorine-containing opener of ATP-sensitive potassium channels, pinacidil-derivative flocalin, on cardiac voltage-gated sodium and calcium channels.

Fluorine-containing pinacidil-derivative flocalin is an effective adenosine triphosphate-sensitive potassium (K(ATP))-channel opener with pronounced vasodilatory, cardioprotective effects and low general toxicity. By activating cardiac K(ATP) channels, flocalin hyperpolarizes cardiac myocytes, decreases their excitability, reduces Ca(2+) entry, and inhibits Ca(2+)-dependent signalling processes. Since our previous studies indicated that the drug also influences the rate of rise and amplitude of the cardiomyocyte's action potential, here we have investigated its possible actions on depolarizing inward currents through voltage-gated sodium (VGSC) and L-type calcium (VGCC) channels.

[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.

[The changes of metabolism in myocardium at ischemia-reperfusion and activating of the ATP-sensitive potassium channels].

In experiments on the anaesthetized dogs with modeling of experimental ischemia (90 min) and reperfusion (180 min) it was investigated the changes of biochemical processes in the different areas of heart (intact, risk and necrotic zone) during intragastric introduction of medicinal form (tablets) of flocalin (the fluorine-containing opener of ATP-sensitive potassium channels) in a dose 2,2 mg/kg. The data analysis allowed to define a few possible cardioprotective mechanisms of flocalin action at ischemia-reperfusion conditions: the preservation of sufficient levels of de novo (by cNOS) NO synthesis, an inhibition of de novo (by iNOS) and salvage (by NADH-dependent nitratreductase) NO synthesis, an inhibition of L-arginine degradation by arginase, an inhibition of oxidizing metabolism due to limitation of ROS and RNS generation, inhibition of free arachidonic acid and eicosanoids synthesis, inhibition of ATP and GTP degradations and, possibly, stimulation of protective haem degradation. These changes may prevent formation of toxic peroxynitrite and suggest the possibility of participating in flocalin-mediated cardioprotective effects of warning a mitochondrial permeability transition pore (MPTP) opening and inhibition of apoptosis and/or necrosis of cardiomyocytes induced by it.

[RNA interference of proteasome subunit of PSMbeta7 gene restricts proteasome subunit PSMbeta1 and PSMbeta5 mRNA expression and peptidyl-glutamyl peptide-hydrolyzing proteasome activity in neonatal cardiomyocytes].

Using small interfering RNA (siRNA) transfection of neonatal cardiomyocytes to inhibit expression of nonproteolytic proteasome beta7 subunit, we observed a significant decrease in beta1 proteolytic subunit mRNA expression. Proteasome peptidyl-glutamyl peptide-hydrolyzing activity decreased to 28% (0.48 +/- 0.

[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.

[Interrelation between cardiac pump function disturbances and cardiac contractility after beta-adrenergic hyperstimulation of the heart in rats].

The complex of structural and functional changes of myocardium was investigated in experiments with rats with chronic beta-adrenergic activation for 1 month. We observed substantial attenuation of myocardial pump function, particularly reduction of stroke volume by 38.50% (P < 0.

[Effect of medical form of flocalin on the course of myocardial reperfusion injury].

In experiments on anaesthetized dogs with modeling of experimental ischemia (90 min) and reperfusion (180 min), the cardioprotective influence of the pharmacological preconditioning caused by intragastric (with a help of catheter) introduction of medicinal form (tablets) of new fluorine-containing opener of ATP-sensitive potassium channels flocalin was shown. Flocalin was introduced in a dose 2.2 mg/kg, which in the conditions of physiological norm has a minimum influence on the parameters of cardiohemodynamic.

[Effects of ubiquitin gene silencing in anoxia-reoxygenation of cultured cardiomyocytes].

Ubiquitin-dependent proteasomal proteolysis is crucialin the turnover of cardiomyocytes functional proteins (actin, myosin, ion channels at. al.), therefore, investigation of cell death after ubiquitin (UBB) gene silencing using RNA interference and anoxia-reoxygenation (AR) modeling appears to be attractive.

Sarcolemmal cardiac K(ATP) channels as a target for the cardioprotective effects of the fluorine-containing pinacidil analogue, flocalin.

Background And Purpose: A class of drugs known as K(ATP) -channel openers induce cardioprotection. This study examined the effects of the novel K(ATP) -channel opener, the fluorine-containing pinacidil derivative, flocalin, on cardiac-specific K(ATP) -channels, excitability of native cardiac myocytes and on the ischaemic heart.

Experimental Approach: The action of flocalin was investigated on: (i) membrane currents through cardiac-specific K(ATP) -channels (I(KATP) ) formed by K(IR) 6.

[Cardioprotective effects of flokalin in experiments in vivo: influence on hemodynamic and myocardial lesions in ischemia-reperfusion].

In experiments on anaesthetized dogs with modeling of experimental ischemia (90 min) and reperfusion (180 min) the cardioprotective influence of the preischemic activation of ATP-sensitive potassium (K(ATP)) channels by intravenous introduction of flokalin, a new fluorine-containing opener of these channels was shown. Flokalin was introduced in dose 0.1 mg/kg of animal body weight which practically did not change the parameters of hemodynamic in conditions of normoxia.

Cardioprotective effect of 5-lipoxygenase gene (ALOX5) silencing in ischemia-reperfusion.

It is well known that 5-lipoxygenase derivates of arachidonic acid play an important pathogenic role during myocardial infarction. Therefore, the gene encoding arachidonate 5-lipoxygenase (ALOX5) appears to be an attractive target for RNA interference (RNAi) application. In experiments on cultivated cardiomyocytes with anoxia-reoxygenation (AR) and in vivo using rat model of heart ischemia-reperfusion (IR) we determined influence of ALOX5 silencing on myocardial cell death.

[Antiatherogenic characteristics of korvitin: effect on proteasome activity of the aorta, heart, and blood cells].

We studied the changes in proteasomal proteolisis during modelling of rabbit cholesterol-induced atherosclerosis. It was determined that in aorta the TL activity of proteasome increased 2.4-fold (P < 0.