Showing papers in "Ukraïns'kyĭ biokhimichnyĭ zhurnal in 2011"

The effect of permeability transition pore opening on reactive oxygen species production in rat brain mitochondria.

Abstract: The influence of mitochondrial permeability transition pore (MPTP) opening on reactive oxygen species (ROS) production in the rat brain mitochondria was studied. It was shown that ROS production is regulated differently by the rate of oxygen consumption and membrane potential, dependent on steady-state or non-equilibrium conditions. Under steady-state conditions, at constant rate of Ca2+-cycling and oxygen consumption, ROS production is potential-dependent and decreases with the inhibition of respiration and mitochondrial depolarization. The constant rate of ROS release is in accord with proportional dependence of the rate of ROS formation on that of oxygen consumption. On the contrary, transition to non-equilibrium state, due to the release of cytochrome c from mitochondria and progressive respiration inhibition, results in the loss of proportionality in the rate of ROS production on the rate of respiration and an exponential rise of ROS production with time, independent of membrane potential. Independent of steady-state or non-equilibrium conditions, the rate of ROS formation is controlled by the rate of potential-dependent uptake of Ca2+ which is the rate-limiting step in ROS production. It was shown that MPTP opening differently regulates ROS production, dependent on Ca2+ concentration. At low calcium MPTP opening results in the decrease in ROS production because of partial mitochondrial depolarization, in spite of sustained increase in oxygen consumption rate by a cyclosporine A-sensitive component due to simultaneous work of Ca2+-uniporter and MPTP as Ca2+-influx and efflux pathways. The effect of MPTP opening at low Ca2+ concentrations is similar to that of Ca2+-ionophore, A-23187. At high calcium MPTP opening results in the increase of ROS release due to the rapid transition to non-equilibrium state because of cytochrome c loss and progressive gating of electron flow in respiratory chain. Thus, under physiological conditions MPTP opening at low intracellular calcium could attenuate oxidative damage and the impairment of neuronal functions by diminishing ROS formation in mitochondria.

[Nicotine effects on mitochondria membrane potential: participation of nicotinic acetylcholine receptors].

Abstract: The effect of nicotine on the mouse liver mitochondria was studied by fluorescent flow cytometry. Mice consumed nicotine during 65 days; alternatively, nicotine was added to isolated mitochondria. Mitochondria of nicotine-treated mice had significantly lower basic levels of membrane potential and granularity as compared to those of the control group. Pre-incubation of the isolated mitochondria with nicotine prevented from dissipation of their membrane potential stimulated with 0.8 microM CaCl2 depending on the dose, and this effect was strengthened by the antagonist of alpha7 nicotinic receptors (alpha7 nAChR) methyllicaconitine. Mitochondria of mice intravenously injected with the antibodies against alpha7 nAChR demonstrated lower levels of membrane potential. Introduction of nicotine, choline, acetylcholine or synthetic alpha7 nAChR agonist PNU 282987 into the incubation medium inhibited Ca2+ accumulation in mitochondria, although the doses of agonists were too low to activate the alpha7 nAChR ion channel. It is concluded that nicotine consumption worsens the functional state of mitochondria by affecting their membrane potential and granularity, and this effect, at least in part, is mediated by alpha7 nAChR desensitization.

Effect of sodium nitroprusside and S-nitrosoglutathione on pigment content and antioxidant system of tocopherol-deficient plants of Arabidopsis thaliana.

Abstract: Sodium nitroprusside (SNP) and S-nitrosoglutathione (GSNO) were used as a source of exogenous nitric oxide (NO) to investigate their effects on biochemical parameters and antioxidant enzyme response in leaves of wild type Columbia and tocopherol-deficient vte4 and vte1 mutant lines of Arabidopsis thaliana plants and possible tocopherol involvement in regulation of antioxidant response under NO-induced stress. SNP enhanced the activity of the enzymes, that scavenge hydrogen peroxide in leaves of all studied lines, and increased glutathione reductase and glutathione-S-transferase activity there. In addition, it decreased the intensity of lipid peroxidation in vte1 mutant line leaves. At the same time, GSNO increased the levels of protein carbonyls and inactivated enzymes ascorbate peroxidase, guaiacol peroxidase and dehydroascorbate reductase in almost all investigated plant lines. In contrast to wild type, GSNO increased superoxide dismutase activity and decreased catalase activity and chlorophyll a/b ratio in the leaves of two mutant lines. It can be assumed that tocopherols in some way are responsible for plant protection against NO-induced stress. However the mechanisms of this protection remain unknown.

Metabolic changes in cells under electromagnetic radiation of mobile communication systems

Abstract: Review is devoted to the analysis of biological effects of microwaves. The results of last years' researches indicated the potential risks of long-term low-level microwaves exposure for human health. The analysis of metabolic changes in living cells under the exposure of microwaves from mobile communication systems indicates that this factor is stressful for cells. Among the reproducible effects of low-level microwave radiation are overexpression of heat shock proteins, an increase of reactive oxygen species level, an increase of intracellular Ca2+, damage of DNA, inhibition of DNA reparation, and induction of apoptosis. Extracellular-signal-regulated kinases ERK and stress-related kinases p38MAPK are involved in metabolic changes. Analysis of current data suggests that the concept of exceptionally thermal mechanism of biological effects of microwaves is not correct. In turn, this raises the question of the need to revaluation of modern electromagnetic standards based on thermal effects of non-ionizing radiation on biological systems.

Fructose as a factor of Carbonyl and oxidative stress development and accelerated aging in the yeast Saccharomyces

Abstract: Excessive and prolonged consumption of fructose may lead to the development of metabolic disorders. However, the mechanisms of disturbances are still discussed. In the present work, the budding yeast Saccharomyces cerevisiae has been used as a model to compare the effects of prolonged consumption of different concentrations of glucose and fructose on certain physiology-biochemical parameters of eukaryotes. It has been shown that the yeast growth, their metabolic activity, intracellular level of glycogen and oxidized proteins were higher in cells grown on fructose. The observation is consistent with the data on a higher in vitro ability of fructose than glucose to initiate glycation which products of which are highly reactive a-dicarbonyl compounds and activated oxygen forms. Thus the intensity of carbonyl and oxidative stress is higher in cells grown on fructose. This can explain a higher rate of aging of yeast consuming fructose as a source of carbon and energy as compared to cells growing on glucose. However, carbohydrate restriction used in this study ham- pered the accumulation of glycogen and oxidized proteins and did not reveal any difference between markers of aging and carbonyl and oxidative stress in yeast grown on glucose and fructose.

Effect of glutamine or glucose deprivation on the expression of cyclin and cyclin-dependent kinase genes in glioma cell line U87 and its subline with suppressed activity of signaling enzyme of endoplasmic reticulum-nuclei-1.

Abstract: Ischemia has been shown to induce a set of complex intracellular signaling events known as the unfolded protein response, which is mediated by endoplasmic reticulum-nuclei-1 sensing enzyme. We have studied the expression of several cyclin and cyclin-dependent kinase genes which participate in the control of cell cycle and proliferation under ischemic conditions (glucose or glutamine deprivation) in endoplasmic reticulum-nuclei-1-deficient glioma cells. It was shown that blockade of endoplasmic reticulum-nuclei signaling enzyme-1, the key endoplasmic reticulum stress sensor, leads to an increase of the expression levels of cyclin-dependent kinase-2 and cyclin A2, D3, E2 and G2 genes but suppresses cyclin D1. Moreover, the expression level of cyclin-dependent kinase-2 as well as cyclin A2, D3 and E2 mRNAs is significantly decreased under glucose or glutamine deprivation conditions both in control and endoplasmic reticulum-nuclei-1-deficient glioma cells. However, cyclin-dependent kinase-4 and -5 mRNA expressions is increased, but in glucose deprivation conditions only. Results of this study have shown that the expression of most tested genes of encoded cyclins and cyclin-dependent kinases is dependent on endoplasmic reticulum-nuclei-1 signaling enzyme function both in normal and glutamine and glucose deprivation conditions and possibly participates in cell adaptive response to endoplasmic reticulum stress associated with ischemia.

[The 5'-deoxyadenylic acid molecule conformational capacity: quantum-mechanical investigation using density functional theory (DFT)].

Abstract: Exhaustive conformational analysis of the 5'-deoxyadenylic acid molecule, has been carried out by the quantum-mechanical density functional theory method at the MP2/6-311++G(d,p)//DFT B3LYP/6-31G(d,p) theory level. As many as 726 of its conformations have been revealed with the relative gas phase Gibbs energies under standard conditions from 0 to 12.1 kcal/mole. It has been shown, that the energetically most favorable conformation has north sugar puckering and synorientation of the nitrogenous base and is stabilized by intramolecular O(p1)H(p1)-N3 and O3'H-O(p) hydrogen bonds. Four conformations have been shown to have their geometry similar to that of AI-DNA and four - of BI-DNA. One conformer of the 5'-deoxyadenylic acid molecule is similar to its sodium salt hexahydrate structure in crystalline state resolved by the X-ray diffraction method and taken from literature. It is shown that effective charges of C4' and C5' atoms are the most sensitive to the molecule conformation ones. The role of the intramolecular OH-N hydrogen bonds in formation of the 5'-deoxyadenylic acid molecule structure has been demonstrated.

[Role of PARP and protein poly-ADP-ribosylation process in regulation of cell functions].

Abstract: This review focuses on the biological role of enzymes involved in posttranslational modification of proteins by their poly-ADP-ribosylation, a NAD-consuming process with an emerging key role in providing fundamental cell functions. To this end, detailed analysis of structural organization in relation to basic functions of the poly(ADP-ribose) polymerase-1 (PARP-1), the founding member of the PARP family, and other poly(ADP-ribose) polymerase isoforms is presented here. These include the current views on the role of PARP family enzymes and processes of poly-ADP-ribosylation of proteins in chromatin structure remodeling, DNA damage repair, regulation of gene expression, and integration of cellular signaling pathways. Considerable attention is paid to the involvement of PARP in cellular functions, particularly in cell division, intracellular transport of macromolcules, proteasomal protein degradation, immune response and caspase-independent necrotic pathways defined as necroptosis (programmed necrosis). In the light of the remarkable successes that have been reported for treating inflammatory disorders and cancer with different classes of PARPs inhibitors, we discuss the prospects of targeting PARPs with therapeutic purposes.

The search of miRNA genes in Bombyx mori nuclear polyhedrosis virus genomes regions complementary to the latest genes

Abstract: The search of miRNA genes in Bombyx mori nuclear polyhedrosis virus genome region complementary to very late genes has been carried out. The search miRNA algorithm in silico was developed by us. It was shown that NPV B. mori genome region containing orf4 gene complementary to ph gene encodes the potential miRNA. NPV B. mori genome region containing p74 gene complementary to p10 gene encodes mature miRNA and potential miRNA. The genome region containing orf1629 encodes two small non-coding RNAs complementary to orf 5'-end of polyhedrin miRNA. From obtained results it is proposed that two small noncoding RNAs complementary to regions of polyhedrin miRNA are included in polyhedra.

Cloning and functional analysis of the GSH1/MET1 gene complementing cysteine and glutathione auxotrophy of the methylotrophic yeast Hansenula polymorpha.

Abstract: The Hansenula polymorpha GSH1/MET1 gene was cloned by complementation of glutathione-dependent growth of H. polymorpha gsh1 mutant isolated previously as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) resistant and cadmium ion sensitive clone. The H. polymorpha GSH1 gene was capable of restoring cadmium ion resistance, MNNG sensitivity, normal glutathione level and cell proliferation on minimal media without addition of cysteine or glutathione, when introduced into the gsh1 mutant cells. It was shown that the H. polymorpha GSH1 gene has homology to the Saccharomyces cerevisiae MET1 gene encoding S-adenosyl-L-methionine uroporphyrinogen III transmethylase, responsible for the biosynthesis of sulfite reductase cofactor, sirohaem. The H. polymorpha GSH1/MET1 gene deletion cassette (Hpgsh1/met1::ScLEU2) was constructed and corresponding null mutants were isolated. Crossing data of the point gsh1 and null gsh1/met1 mutants demonstrated that both alleles were located to the same gene. The null gsh1/met1 mutant showed total growth restoration on minimal media supplemented with cysteine or glutathione as a sole sulfur source, but not with inorganic (sulfate, sulfite) or organic (methionine, S-adenosylmethionine) sources of sulfur. Moreover, both the point gsh1 and null gsh1/met1 mutants displayed increased sensitivity to the toxic carbon substrate methanol, formaldehyde, organic peroxide and cadmium ions.

[Conformational variety and physical properties of the 1,2-dideoxyribofuranose-5-phosphate, the model DNA monomer structural unit].

Abstract: The results of exhaustive quantum-mechanical conformational analysis of 1,2-dideoxyribofuranose-5-phosphate molecule, the model DNA backbone structural unit, are presented As many as 282 conformations with the relative Gibbs energies from 0 to 89 kcal/mole have been obtained at the MP2/cc-pVTZ // DFT B3LYP/cc-pVTZ theory level Among them seven structures are similar to those of the DNA backbone in its AI, BI and ZII forms, while the B-DNA-like conformation has the lowest Gibbs energy (deltaG = 33 kcal/mole) It is shown that the relaxed force constants values for conformational parameters of all DNA-like conformations satisfy inequality K gamma > K alpha > K epsilon > K beta

[Activation of the phosphatidylinositol-3'-kinase pathway with lectin-induced signal through sialo-containing glycoproteins of leukocyte membranes under type 1 diabetes mellitus].

Abstract: The influence of wortmannin and sialospecific lectins on the translocation of p85alpha regulatory subunit of phosphatidylinositol-3'-kinase (PI-3'-kinase) between membrane and cytosolic fractions of the mononuclear and polymorphonuclear leukocytes in healthy donors and patients with type 1 diabetes mellitus (DM) was investigated. It was found out that under type 1 DM PI-3'-kinase takes active part in the transduction of lectin-induced signal through membrane glycoprotein receptors that contain terminal sialic acids linked to subterminal carbohydrate residues with (alpha2-->6) glycosidic bond.

[Folate-related processes in human placenta: gene expression, aminothiols, proliferation and apoptosis].

Abstract: The paper contains short information concerning the role of folate-related processes in cell metabolism and multiple diseases which are characterized by hyperhomocysteinemia. The authors represent more detailed information about the folate-related processes in human placenta, namely about the content of aminothiols at different allelic variants of placental methylenetetrahydrofolate reductase during the course of physiological pregnancy and preeclampsia. The existing data concerning the expression and catalytic activity of corresponding enzymes are corroborated by the authors' own results that proved for the first time the functional activity of transsulfuration pathway in human placenta. This pathway is activated in placental explants in parallel with down-regulation of proliferation and up-regulation of apoptosis when hyperhomocysteinemia is imitated by high concentration of homocysteine in culture medium. On the whole the presented data point to the importance of placental folate-related processes for its normal function.

Molecular mechanisms of circadian clock functioning

Abstract: Most physiological processes of all organisms are rhythmic with a period of about 24 h and are generated by an endogenous biological CLOCK present in all cells. However, there is also a central CLOCK--the primary circadian pacemaker which is localized in the suprachiasmatic nuclei of the mammalian hypothalamus. Factors of groups Period (PER1, PER2 and PER3), BMAL (BMAL1 and BMAL2), CRYptochromes (CRY1 and CRY2) as well as some other factors are the components of this circadian CLOCK system. Some of these genes contain E-box sequences and their expression is regulated by a transcription factor complex CLOCK-BMAL1. The enzymes responsible for the post-translational modification of circadian gene products are also the components of circadian CLOCK system. These enzymes define CLOCK's work and determine the duration of circadian biorhythm and functional state of the whole organism. The most important of these enzymes are casein kinase-1epsilon and -1delta. We have analysed data about the interconnection between the circadian CLOCK system, cell cycle, and cancerogenesis as well as about the sensitivity of circadian gene expression to the action of toxic agents and nanomaterials.

Glutathione level of Desulfovibrio desulfuricans IMV K-6 under the influence of heavy metal salts.

Abstract: Glutathione is the metal stress protector and changes of its level in the sulfate-reducing bacteria cells under the influence of heavy metal salts have not been studied yet. CdCl2, Pb(NO3)2, CuCl2, and ZnCl2 influence on the total glutathione level in cell-free extracts of sulfate-reducing bacteria Desulfovibrio desulfuricans IMV K-6 was studied. The research has been carried out using Ellman, Lowry methods, statistical processing of the results. It was shown that the glutathione level depends on the heavy metal salts concentration in the medium. The total glutathione level was the highest under the influence of Pb(NO3)2. Other salts were also toxic to bacteria because glutathione level increased in bacterial cells after addition of these salts to the medium. On the basis of the results of our work the range of heavy metal salts influence on D. desulfuricans IMV K-6 cells glutathione level has been formed for the first time: Pb(NO3)2 > CuCl2 > CdCl2 > ZnCl2.

[Function of transport H+-ATPases in plant cell plasma and vacuolar membranes of maize under salt stress conditions and effect of adaptogenic preparations].

Abstract: Participations of electrogenic H+-pumps of plasma and vacuolar membranes represented by E1-E2 and V-type H+-ATPases in plant cell adaptation to salt stress conditions has been studied by determination of their transport activities. Experiments were carried out on corn seedlings exposed during 1 or 10 days at 0.1 M NaCl. Preparations Methyure and Ivine were used by seed soaking at 10(-7) M. Plasma and vacuolar membrane fractions were isolated from corn seedling roots. In variants without NaCl a hydrolytical activity of plasma membrane H+-ATPase was increased with seedling age and its transport one was changed insignificantly, wherease the response of the weaker vacuolar H+-ATPase was opposite. NaCl exposition decreased hydrolytical activities of both H+-ATPases and increased their transport ones. These results demonstrated amplification of H+-pumps function especially represented by vacuolar H+-ATPase. Both preparations, Methyure mainly, caused a further increase of transport activity which was more expressed in NaCl variants. Obtained results showed the important role of these H+-pumps in plant adaptation under salt stress conditions realized by energetical maintenance of the secondary active Na+/H+ -antiporters which remove Na+ from cytoplasm.

[Regulation of the mitochondrial ATP-sensitive potassium channel in rat uterus cells by ROS].

Abstract: In previous study we demonstrated the presence of ATP-sensitive potassium current in the inner mitochondrial membrane, which was sensitive to diazoxide and glybenclamide, in mitochondria isolated from the rat uterus. This current was supposed to be operated by mitochondrial ATP-sensitive potassium channel (mitoK(ATP)). Regulation of the mitoK(ATP) in uterus cells is not studied well enough yet. It is well known that the reactive oxygen species (ROS) can play a dual role. They can damage cells in high concentrations, but they can also act as messengers in cellular signaling, mediating survival of cells under stress conditions. ROS are known to activate mitoK(ATP) during the oxidative stress in the brain and heart, conferring the protection of cells. The present study examined whether ROS mediate the mitoK(ATP) activation in myometrium cells. Oxidative stress was induced by rotenone. ROS generation was measured by 2',7'-dichlorofluorescin diacetate. The massive induction of ROS production was demonstrated in the presence of rotenone. Hyperpolarization of the mitochondrial membrane was also detected with the use of the potential-sensitive dye DiOC6 (3,3'-dihexyloxacarbocyanine iodide). Diazoxide, a selective activator of mitoK(ATP), depolarized mitochondrial membrane either under oxidative stress or under normal conditions, while mitoK(ATP) blocker glybenclamide effectively restored mitochondrial potential in rat myocytes. Estimated value for diazoxide to mitoK(ATP) under normoxia was four times higher than under oxidative stress conditions: 5.01 +/- 1.47-10(-6) M and 1.24 +/- 0.21 x 10(-6) M respectively. The ROS scavenger N-acetylcysteine (NAC) successfully eliminates depolarization of mitochondrial membrane by diazoxide under oxidative stress. These results suggest that elimination of ROS by NAC prevents the activation of mitoK(ATP) under oxidative stress. Taking into account the higher affinity of diazoxide to mitoK(ATP) under stress conditions than under normoxia, we conclude that the oxidative stress conditions are more favourable than normoxia for the activation of mitoK(ATP). Thus we hypothesize that the ROS regulate the activity of the mitoK(ATP) in myocytes.

[Evaluation of biological effects of cobalt-nanocomposites with the use of biochemical markers of bivalve mollusk Anodonta cygnea].

Abstract: Intensive implementation of nanomaterials requires development of novel methods for evaluation of their potential ecotoxicity. The aim of our study was to identify specific characteristics of the effect of cobalt-nanocomposite (Co-NC) on the molecular stress-responsive system in the digestive gland of bivalve mollusk Anodonta cygnea. Nanocomposite was synthesized by mixing alcohol solution of copolymer N-vinylpirrolidone, 5-(tret-butylperoxy)-5-methyl-1-hexene-3-yne and dimethylaminoethylmetacrylate and cobalt (II) chloride. After 14 days of the mollusk exposure in the presence of Co-NC, CoCl, or corresponding polymer substance it was shown that the Co-NC, in contrast to other agents, does not cause an oxidative stress due to the superoxide dismutase activity, metallotioneins (MTs) level, glutathione redox index and oxyradical production. Multivariate analysis confirmed specific features of the Co-NC's effect related to an enhanced expression of MTs, while CoCl2 activated lactate dehydrogenate and oxyradical production, and polymer substance enhanced glutathione transferase activity.

Biochemical mechanisms of chromium action in the human and animal organism

Abstract: Modern data concerning biologic characteristics of chromium (Cr3+) its placement in nature, accessibility and metabolic action of its different forms in humans and animals is presented in this survey. Essentiality of chromium for humans is emphasized, data about consumption norms of this microelement and its use for curing different diseases especially diabetes mellitus and atherosclerosis of vessels are presented. The biochemical mechanisms of Cr3+ effect on the metabolism in the human and animal organism are analyzed. It is shown that the organism reacts to chrome additions by the change of some metabolism links. Chrome influences positively growth and development of foetus, stimulates metabolism of glucose and insulin in the humans and animals. However, at the set chromium requirements it is necessary to take into account its low availability in food, high release of Cr3+ from the organism under the influence of stress factors, considerable decline of its level with age, and also in the period of pregnancy and lactation. Therefore experimental researches of introduction of Cr3+ additions to the diet of people and forage of animals taking into account their body mass, age and clinical state, can explain the biochemical mechanisms of biological action of this microelement.

[Influence of antitumor system rhenium-platinum on biochemical state of the liver].

Abstract: Influence of the antitumour rhenium-platinum system on biochemical liver characteristics in the model of tumor growth (Guerin carcinoma) was studied and possible hepatoprotective activity of rhenium cluster compounds when introducing them in different forms was shown, that was confirmed by decreasing of diagnostic enzymes activity in blood (aminotransferase--AST 6 times and ALT 5.6 times, lactatedehydrogenase 4.9 times, gamma-glutamyltranspeptidase 3.6 times) and normalization of morphological state of the liver cells. The hepatoprotective activity of the cluster rhenium compound with adamanthyl ligands was confirmed in the model of acute toxic hepatitis. Introduction of this compound led to reduction of the concentration of MDA in homogenates of liver tissue (2 times), and in blood plasma (3.8 times); to reduction of levels of diagnostic liver enzymes in blood--AST and ALT 5.8 and 5.5 times respectively in comparison with control group. Some aspects of the mechanism of hepatoprotection were discussed, that included the presence of conjugated systems around the quadrupol rhenium-rhenium bond and alkyl radicals with significant positive inductive effects.

[The influence of ATP-dependent K(+)-channel diazoxide opener on the opening of mitochondrial permeability transition pore in rat liver mitochondria].

Abstract: The influence of mitochondrial ATP-dependent K(+)-channel (K+(ATP)-channel) opener, diazoxide (DZ) on the mitochondrial permeability transition pore (MPTP) opening in rat liver mitochondria is studied. In the absence of DZ the MPTP opening leads to the increase in the rate of K(+)- and Ca(2+)-cycling supported by the simultaneous functioning of K(+)-channels and K+/H(+)-antiporter, and also Ca(2+)-uniporter together with MPTP as the cations influx and efflux pathways. Independent of MPTP opening, the activation of both constitutes of K(+)-cycle, K(+)-uptake as well as K+/H(+)-exchange, by DZ is observed. It is shown that the activation of transmembrane exchange of K+, combined with MPTP opening, results in partial inhibition of the latter. A simple methodical approach for the estimation of DZ influence on the open state of mitochondrial pore is proposed. It is shown that MPTP closure followed by Ca2+ reentry to the matrix is accompanied by the K+/H(+)-exchange inhibition which takes place in the same timeframes as the increase in matrix Ca2+ content. Relevant to physiological conditions, an important physiological function of MPTP is revealed, that is the maintenance of relatively low matrix level of Ca2+ accompanied by the acceleration of transmembrane ion exchange (K+ and Ca2+) which could strongly influence the energy state and energy-dependent processes in mitochondria.

[Astroglia proteins in the rat brain in experimental chronic hepatitis and 2-oxoglutarate effect].

Abstract: A probable increase of the level of calcium-binding protein S100b and soluble form of glial fibrillary acidic protein (GFAP), as well as reducing the level of filament GFAP in the brain of Wistar rats under hepatic encephalopathy development caused by chronic hepatitis (HP) were shown. Increasing concentrations of S100b may stimulate the disassembly of intermediate filaments of astrocytes. The immunohistochemical analysis helps to reveal that astrocytes in the brain of rats that had HP lose the characteristic stellate shape and swelling. Immunoblotting result have shown the fragmentation of the main filament form of GFAP and appearance of low mass derivates. Application of 2-oxoglutarate (2.28 g/l of drinking water during 10 days after the onset of chronic hepatitis) stabilized the studied proteins and the state of astroglia.

The liver and kidneys biochemical indices at the experimental pancreatitis in case of the administration of nitric oxide synthesis modulators and recombinant superoxide dismutase

Abstract: The rats liver and kidneys function indices were studied in case of administration of recombinant superoxide dismutase drug, precursor of nitric oxide L-arginine and the blocker of inducible NO-synthase aminoguanidine. The disturbances in functioning of prooxidant-antioxidant system (a decrease of activity of superoxide dismutase, katalaze, amount of restored glutathione, growth of the level of hydroperoxide lipids, TBA-active products), mitochondrial electron-transport pathways (a decrease in activity of succinatedehydrogenaze, cytochrome oxydaze), a rise of nitrite-anion level in the liver and kidneys, increase of alpha-amylase activity and tumor necrosis factor alpha serum concentration were established on the model of pancreas injury in white male rats. Under these circumstances aminoguanidine attenuated the oxidative stress in the liver and kidneys due to normalization of nitric oxide synthesis. The ability to activate the antioxidant system was proved by combined usage of recombinant superoxide dismutase and aminoguanidine. It was determined that recombinant superoxide dismutase partially decreases the negative influence of L-arginine and improves the biochemical indices of the liver and kidneys function in rats with acute experimental pancreatitis.

Tissue specificity of lipid peroxidation under emotional stress in rats

Abstract: The intensity of lipid peroxidation and activity of antioxidant system enzymes in the blood plasma, brain and cardial muscle of laboratory rats under 40 days of isolation and violation of diurnal cycle was studied. The obtained data show that on the background of concentration changes in NO changes also take place in the intensity of lipid peroxidation process, indicated by changes in the concentration of TBA-active products and diene conjugates. The changes taking place in the activity of superoxidedismutase, catalase, succinatdehydrogenase, creatine kinase and aldolase under stress were studied. The resulting data show that isolation of animals and violation of diurnal cycle are the factors causing a significant reduction in the energy metabolism in the brain and heart tissue cells and resulting in oxidative stress that, in its turn, may become the reason for development of toxic radicals. Furthermore, prolonged stress may result in irreversible processes that are considered to be the reasons for significant pathologies of the cardiovascular system.

[Metal-binding functions and antioxidant properties in human thyroid gland under iodine deficient nodular colloidal goiter].

Abstract: Copper and zinc levels in the tissue of thyroid gland (TG) and their metal-binding proteins metallothioneins (MT) as well as state of the antioxidant system in persons that had no thyroid disease and patients with endemic iodine deficiency nodular colloidal goiter has been investigated. In the patients with thyroid disease, oxidative damage was indicated despite elevated levels of MT-SH and glutathione, and elevated copper and decreased zinc concentration in TG tissue. MTs partly bound the excess of copper but its concentration in the unbound to MT form was two-fold compared to the control value.

[Antioxidative effect of the N-stearoylethanolamine in the heart tissue and blood plasma of rats under doxorubicin treatment]

Abstract: The influence of N-stearoylethanolamine on the alterated antioxidant enzyme activity in the heart tissue and blood plasma of rats under the doxorubicin treatment was investigated. It was shown that doxorubicin administration caused the decrease of antioxidant enzymes activity (superoxide dismutase and glutathione peroxidase) in the heart tissue. Administration of the NSE promoted the partial normalization of these enzymes activity. It was shown that doxorubicin treatment caused the increase of the urea and creatinine level in the blood plasma of experimental animals. The NSE administration normalized the level of the urea and did not affect creatinine level.

[Study on derivatives of 5-amino-4-acylamino-1H-pyrazole as inhibitors of furin].

Abstract: A series of 5-amino-1H-pyrazoles was synthesized and studied as inhibitors of furin. The most potent compound, 5-amino-4-acetylamino-3-(4-methylphenylamino)1H-pyrazole, was found to retard the activity of furin by mixed-type inhibition with K = 288 microM. These findings permit to plan new ways for chemical modifications of the 5-amino-1H-pyrazole structure and design more potent furin inhibitors of non-peptide nature.

[Coordinative compounds of zinc with N-substituted thiocarbamoyl-N'-pentamethylensulfenamides--activity modifiers of enzymes of proteolytic and glycolytic action].

Abstract: The influence of a number of coordinative compounds of zinc with N-substituted thiocarbamoil-N'-pentamethylensulfenamides on activity of elastase, alpha-L-rhamnosidase and alpha-galactosidases evidence for a possibility of their usage as stimulators or inhibitors of enzymes tested have been studied. It was shown that all the compounds in concentration of 0.1 and 0.01% inhibited by 90-100% Bacillus thuringiensis 27-88Els+ elastase activity. [Zn(L2)Br2], [Zn(L1)(NCS)2] and [Zn(L3)(NCS)2] at 20 h exposition activated Cryptococcus albidus 1001 alpha-L-rhamnosidase activity. The rest of compounds influenced it on the control level or inhibited it by 7-23%. The obtained results testify that essential role is not played by separate fragments (L-ligand and anions), but by molecules of zinc complexes as a whole. All the studied complexes, exept for [Zn(L3)(NCS)2], induced alpha-L-rhamnosidase activity of Eupenicillium erubescens 248 (7 to 60%). All zinc compounds (concentration 0.01%, exposition time - 60 min) influenced at the control level Aspergillus niger and Cladosporium cladosporioides alpha-galactosidases activity, however inhibited (up to 20%) activity of Penicillium canescens alpha-galactosidase. The increasing of exposition time of the compounds tested with enzymes up to 20 h testify to selective action of separate compounds on enzymes tested. The data obtained prove, that the character of interaction of zinc complexes is changed depending on the enzyme tested and its strain-producer.

[The search of microRNA genes encoded in antiparallel chains of Autographa californica nuclear polyhedrosis virus genome regions, including most late and complementary genes].

Abstract: It was shown using bioinformatic approach by analysis of alternative transcriptes secondary structure, that A. californica nuclear polyhedrosis virus gene ph encoded two mature miRNAs and three potential miRNAs. Gene orf1629 complementary to gene ph did not encode miRNAs and pre-miRNA-Cs. Gene p10 encodes mature and potential miRNA. Gene p74 located on complementary chain encodes three mature miRNAs.

[Exocytotic steps in cell-free system after cholesterol deprivation in synaptosomal plasma membranes and synaptic vesicles].

Abstract: Using a cell-free system we investigated a specific role of cholesterol in exocytotic processes To modulate the cholesterol content in membrane methyl-beta-cyclodextrin was used as a cholesterol binding agent The experimental conditions for cholesterol depletion from synaptosomal membrane structures were determined and depended on methyl-beta-cyclodextrin concentration, time and mediums temperature The role of cholesterol was studied on the stages of synaptic vesicles docking and Ca(2+)-stimulated fusion which are the components of multivesicular compound exocytosis Using dynamic light scattering technique we have found that after cholesterol depletion from synaptic vesicles the process of their aggregation (docking) remains unchanged It was found that the rate of calcium-triggered fusion of synaptic vesicles depends on the membrane level of cholesterol The decreasing level of synaptosomal plasma membrane cholesterol by 8% leads to suppression of the Ca(2+)-dependent membrane fusion with synaptic vesicles But, under 25% reduction of plasma membrane cholesterol the level of membrane merging with synaptic vesicles did not differ from control; probably this is due to changes in physical properties of lipid bilayer and/ or disturbances in function of membrane proteins driving this process In cholesterol depleted synaptosomes the exocytotic release of glutamate stimulated by calcium was decreased by 32% Obtained data suggest that the cholesterol concenration in synaptosomal plasma membranes or synaptic vesicles is the crucial determinant for synaptic transmission efficiency in nerve terminals