WorldWideScience

Sample records for nitric oxide-derived species

  1. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates

    NARCIS (Netherlands)

    Opländer, C.; Volkmar, C.M.; Paunel-Görgülü, A.; van Faassen, E.E.H.; Heiss, C.

    2009-01-01

    Rationale: Human skin contains photolabile nitric oxide derivates like nitrite and S-nitroso thiols, which after UVA irradiation, decompose and lead to the formation of vasoactive NO. Objective: Here, we investigated whether whole body UVA irradiation influences the blood pressure of healthy

  2. Cyclic nitroxides inhibit the toxicity of nitric oxide-derived oxidants: mechanisms and implications

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    Ohara Augusto

    2008-03-01

    Full Text Available The substantial therapeutic potential of tempol (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy and related cyclic nitroxides as antioxidants has stimulated innumerous studies of their reactions with reactive oxygen species. In comparison, reactions of nitroxides with nitric oxide-derived oxidants have been less frequently investigated. Nevertheless, this is relevant because tempol has also been shown to protect animals from injuries associated with inflammatory conditions, which are characterized by the increased production of nitric oxide and its derived oxidants. Here, we review recent studies addressing the mechanisms by which cyclic nitroxides attenuate the toxicity of nitric oxidederived oxidants. As an example, we present data showing that tempol protects mice from acetaminophen-induced hepatotoxicity and discuss the possible protection mechanism. In view of the summarized studies, it is proposed that nitroxides attenuate tissue injury under inflammatory conditions mainly because of their ability to react rapidly with nitrogen dioxide and carbonate radical. In the process the nitroxides are oxidized to the corresponding oxammonium cation, which, in turn, can be recycled back to the nitroxides by reacting with upstream species, such as peroxynitrite and hydrogen peroxide, or with cellular reductants. An auxiliary protection mechanism may be down-regulation of inducible nitric oxide synthase expression. The possible therapeutic implications of these mechanisms are addressed.O considerável potencial terapêutico de tempol (4-hidroxi-2,2, 6,6-tetrametil-1piperiniloxila e nitróxidos cíclicos relacionados como antioxidantes tem estimulado inúmeros estudos de suas reações com espécies reativas derivadas de oxigênio. Em comparação, as reações de nitróxidos com oxidantes derivados do óxido nítrico têm sido investigadas menos frequentemente. Todavia, essas reações são relevantes porque o tempol é também capaz de proteger

  3. Subclinical mastitis in goats is associated with upregulation of nitric oxide-derived oxidative stress that causes reduction of milk antioxidative properties and impairment of its quality.

    Science.gov (United States)

    Silanikove, Nissim; Merin, Uzi; Shapiro, Fira; Leitner, Gabriel

    2014-01-01

    The aim of this study was to verify the existence of a nitric oxide (NO) cycle in goat milk and to study how changes in it affect milk composition during subclinical mastitis. Fifteen lactating dairy goats in which one udder-half was free from bacterial infection and the contra-lateral one was naturally infected with various species of coagulase-negative staphylococci were used. In comparison to uninfected glands, subclinical mastitis was associated with a decrease in milk yield, lactose concentration, and curd yield and an increase in nitrite and nitrate concentrations and with measurements reflecting increased formation of NO-derived free-radical nitrogen dioxide. The occurrence of NO cycling in goat milk was largely confirmed. The increase in the NO-derived stress during subclinical infection was not associated with significant increase in oxidatively modified substances, 3-nitrotyrosine, and carbonyls on proteins, but with increased levels of peroxides on fat. However, the relatively modest nitrosative stress in subclinically infected glands was associated with significant reduction in total antioxidant capacity and vitamin C levels in milk. We concluded that subclinical mastitis in goats caused by coagulase-negative staphylococci imposes negative changes in milk yield, milk quality for cheese production, and negatively affects the nutritional value of milk as food. Thus, subclinical mastitis in goats should be considered as a serious economic burden both by farmers and by the dairy industry. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Effect of storage levels of nitric oxide derivatives in blood components [v1; ref status: indexed, http://f1000r.es/WDkFtz

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    Melissa A Qazi

    2012-10-01

    Full Text Available Background: Potential deleterious effects of red blood cell (RBC transfusions, especially from blood kept at length, have been ascribed to biochemical changes during storage, including those of nitric oxide (NO metabolism. Study methods and design: In this study, NO metabolites, nitrite and nitrate, were quantified in RBCs and whole blood with time of storage. Whole blood (WB, leukoreduced (LR, and non-leukoreduced (NLR components were obtained from healthy volunteer donors and stored in polyvinyl chloride bags for 42 days. Nitrite and nitrate were measured using reductive gas-phase chemiluminescence. Results: Nitrite concentrations initially decreased rapidly from about 150nmol/L, but stabilized at about 44nmol/L in room air for up to 42 days. Nitrate concentrations remained stable during storage at about 35µmol/L. Cells from bags maintained in an argon chamber showed decreased nitrite levels compared to those maintained in room air. Inhibition of enzymes implicated in the NO cycle did not alter nitrite levels. Conclusion: As erythrocytes may contribute to the control of blood flow and oxygen delivery through reduction of nitrite to NO under hypoxic conditions, the present findings provide insight into possible effects of blood transfusion. These measurements may explain some adverse effects of RBC transfusion and suggest ways of optimizing the preservation of stored blood.

  5. Nitric oxide and reactive oxygen species in plant biotic interactions.

    Science.gov (United States)

    Scheler, Claudia; Durner, Jörg; Astier, Jeremy

    2013-08-01

    Nitric oxide (NO) and reactive oxygen species (ROS) are important signaling molecules in plants. Recent progress has been made in defining their role during plant biotic interactions. Over the last decade, their function in disease resistance has been highlighted and focused a lot of investigations. Moreover, NO and ROS have recently emerged as important players of defense responses after herbivore attacks. Besides their role in plant adaptive response development, NO and ROS have been demonstrated to be involved in symbiotic interactions between plants and microorganisms. Here we review recent data concerning these three sides of NO and ROS functions in plant biotic interactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Reactive Oxygen Species and Nitric Oxide in Cutaneous Leishmaniasis

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    Maria Fátima Horta

    2012-01-01

    Full Text Available Cutaneous leishmaniasis affects millions of people around the world. Several species of Leishmania infect mouse strains, and murine models closely reproduce the cutaneous lesions caused by the parasite in humans. Mouse models have enabled studies on the pathogenesis and effector mechanisms of host resistance to infection. Here, we review the role of nitric oxide (NO, reactive oxygen species (ROS, and peroxynitrite (ONOO− in the control of parasites by macrophages, which are both the host cells and the effector cells. We also discuss the role of neutrophil-derived oxygen and nitrogen reactive species during infection with Leishmania. We emphasize the role of these cells in the outcome of leishmaniasis early after infection, before the adaptive Th-cell immune response.

  7. Nitric oxide and reactive oxygen species in the nucleus revisited.

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    Provost, Chantale; Choufani, Faten; Avedanian, Levon; Bkaily, Ghassan; Gobeil, Fernand; Jacques, Danielle

    2010-03-01

    Recent work from our group showed that the nuclear envelope membranes contain several G protein-coupled receptors, including prostaglandin E2 (EP3R) and endothelin-1 (ET-1) receptors. Activation of EP3R increased endothelial nitric oxide synthase (eNOS) RNA expression in nuclei. eNOS and inducible NOS (iNOS) are reported to also be present at the nuclear level. Furthermore, reactive oxygen species (ROS) were also localized at the nuclear level. In this review, we show that stimulation with NO donor sodium nitroprusside results in an increase of intranuclear calcium that was dependent on guanylate cyclase activation, but independent of MAPK. This increase in nuclear calcium correlated with an increase in nuclear transcription of iNOS. H2O2 and ET-1 increase both cytosolic and nuclear ROS in human endocardial endothelial cells and in human aortic vascular smooth muscle cells. This increase in ROS levels by H2O2 and ET-1 was reversed by the antioxidant glutathione. In addition, our results strongly suggest that cytosolic signalization is not only transmitted to the nucleus but is also generated by the nucleus. Furthermore, we demonstrate that oxidative stress can be sensed by the nucleus. These results highly suggest that ROS formation is also generated directly by the nucleus and that free radicals may contribute to ET-1 regulation of nuclear Ca2+ homeostasis.

  8. Nitric oxide and reactive oxygen species in limb vascular function

    DEFF Research Database (Denmark)

    Gliemann, Lasse; Nyberg, Michael Permin; Hellsten, Ylva

    2014-01-01

    , the extent of enzymatic and non-enzymatic formation of NO and on the other hand, removal of NO, which in part is dependent on the reaction of NO with reactive oxygen species (ROS). The presence of ROS is dependent on the extent of ROS formation via mitochondria and/or enzymes such as NAD(P)H oxidase...... the bioavailability of NO but may also cause cellular damage in the cardiovascular system. Physical activity has been shown to greatly improve cardiovascular function, in part through improved bioavailability of NO, enhanced endogenous antioxidant defense and a lowering of the expression of ROS forming enzymes...

  9. Reactive oxygen species and nitric oxide mediate plasticity of neuronal calcium signaling

    Science.gov (United States)

    Yermolaieva, Olena; Brot, Nathan; Weissbach, Herbert; Heinemann, Stefan H.; Hoshi, Toshinori

    2000-01-01

    Reactive oxygen species (ROS) and nitric oxide (NO) are important participants in signal transduction that could provide the cellular basis for activity-dependent regulation of neuronal excitability. In young rat cortical brain slices and undifferentiated PC12 cells, paired application of depolarization/agonist stimulation and oxidation induces long-lasting potentiation of subsequent Ca2+ signaling that is reversed by hypoxia. This potentiation critically depends on NO production and involves cellular ROS utilization. The ability to develop the Ca2+ signal potentiation is regulated by the developmental stage of nerve tissue, decreasing markedly in adult rat cortical neurons and differentiated PC12 cells.

  10. Interaction between Mitochondrial Reactive Oxygen Species, Heme Oxygenase, and Nitric Oxide Synthase Stimulates Phagocytosis in Macrophages

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    Andrea Müllebner

    2018-01-01

    Full Text Available BackgroundMacrophages are cells of the innate immune system that populate every organ. They are required not only for defense against invading pathogens and tissue repair but also for maintenance of tissue homeostasis and iron homeostasis.AimThe aim of this study is to understand whether heme oxygenase (HO and nitric oxide synthase (NOS contribute to the regulation of nicotinamide adenine dinucleotide phosphate oxidase (NOX activity and phagocytosis, two key components of macrophage function.MethodsThis study was carried out using resting J774A.1 macrophages treated with hemin or vehicle. Activity of NOS, HO, or NOX was inhibited using specific inhibitors. Reactive oxygen species (ROS formation was determined by Amplex® red assay, and phagocytosis was measured using fluorescein isothiocyanate-labeled bacteria. In addition, we analyzed the fate of the intracellular heme by using electron spin resonance.ResultsWe show that both enzymes NOS and HO are essential for phagocytic activity of macrophages. NOS does not directly affect phagocytosis, but stimulates NOX activity via nitric oxide-triggered ROS production of mitochondria. Treatment of macrophages with hemin results in intracellular accumulation of ferrous heme and an inhibition of phagocytosis. In contrast to NOS, HO products, including carbon monoxide, neither clearly affect NOX activity nor clearly affect phagocytosis, but phagocytosis is accelerated by HO-mediated degradation of heme.ConclusionBoth enzymes contribute to the bactericidal activity of macrophages independently, by controlling different pathways.

  11. Antioxidant, antityrosinase, anticholinesterase, and nitric oxide inhibition activities of three malaysian macaranga species.

    Science.gov (United States)

    Mazlan, Nor Aishah; Mediani, Ahmed; Abas, Faridah; Ahmad, Syahida; Shaari, Khozirah; Khamis, Shamsul; Lajis, N H

    2013-01-01

    The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.

  12. Antioxidant, Antityrosinase, Anticholinesterase, and Nitric Oxide Inhibition Activities of Three Malaysian Macaranga Species

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    Nor Aishah Mazlan

    2013-01-01

    Full Text Available The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE/100 g and free radical scavenging activity (IC50 = 0.063 mg/mL. All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%. The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp. of the acetylcholinesterase enzyme (AChE, while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE. Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.. These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.

  13. Emissions of nitric oxide from 79 plant species in response to simulated nitrogen deposition.

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    Chen, Juan; Wu, Fei-Hua; Liu, Ting-Wu; Chen, Lei; Xiao, Qiang; Dong, Xue-Jun; He, Jun-Xian; Pei, Zhen-Ming; Zheng, Hai-Lei

    2012-01-01

    To assess the potential contribution of nitric oxide (NO) emission from the plants grown under the increasing nitrogen (N) deposition to atmospheric NO budget, the effects of simulated N deposition on NO emission and various leaf traits (e.g., specific leaf area, leaf N concentration, net photosynthetic rate, etc.) were investigated in 79 plant species classified by 13 plant functional groups. Simulated N deposition induced the significant increase of NO emission from most functional groups, especially from conifer, gymnosperm and C(3) herb. Moreover, the change rate of NO emission was significantly correlated with the change rate of various leaf traits. We conclude that the plants grown under atmospheric N deposition, especially in conifer, gymnosperm and C(3) herb, should be taken into account as an important biological source of NO and potentially contribute to atmospheric NO budget. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Involvement of reactive oxygen species and nitric oxide radicals in activation and proliferation of rat hepatic stellate cells

    NARCIS (Netherlands)

    Svegliati-Baroni, G; Saccomanno, S; van Goor, H; Jansen, P; Benedetti, A; Moshage, H

    Background/Aims: Reactive oxygen species (ROS) induce HSCs activation, proliferation and collagen gene expression in vitro. Nitric oxide (NO) represents a reactive molecule that reacts with ROS, yielding peroxynitrite. We thus verified the effect of NO on ROS-induced HSCs proliferation in vitro and

  15. New insights into reactive oxygen species and nitric oxide signalling under low oxygen in plants.

    Science.gov (United States)

    Pucciariello, Chiara; Perata, Pierdomenico

    2017-04-01

    Plants produce reactive oxygen species (ROS) when exposed to low oxygen (O 2 ). Much experimental evidence has demonstrated the existence of an oxidative burst when there is an O 2 shortage. This originates at various subcellular sites. The activation of NADPH oxidase(s), in complex with other proteins, is responsible for ROS production at the plasma membrane. Another source of low O 2 -dependent ROS is the mitochondrial electron transport chain, which misfunctions when low O 2 limits its activity. Arabidopsis mutants impaired in proteins playing a role in ROS production display an intolerant phenotype to anoxia and submergence, suggesting a role in acclimation to stress. In rice, the presence of the submergence 1A (SUB1A) gene for submergence tolerance is associated with a higher capacity to scavenge ROS. Additionally, the destabilization of group VII ethylene responsive factors, which are involved in the direct O 2 sensing mechanism, requires nitric oxide (NO). All this evidence suggests the existence of a ROS and NO - low O 2 mechanism interplay which likely includes sensing, anaerobic metabolism and acclimation to stress. In this review, we summarize the most recent findings on this topic, formulating hypotheses on the basis of the latest advances. © 2016 John Wiley & Sons Ltd.

  16. Nitric Oxide and Reactive Oxygen Species in the Pathogenesis of Preeclampsia

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    Keiichi Matsubara

    2015-03-01

    Full Text Available Preeclampsia (PE is characterized by disturbed extravillous trophoblast migration toward uterine spiral arteries leading to increased uteroplacental vascular resistance and by vascular dysfunction resulting in reduced systemic vasodilatory properties. Its pathogenesis is mediated by an altered bioavailability of nitric oxide (NO and tissue damage caused by increased levels of reactive oxygen species (ROS. Furthermore, superoxide (O2− rapidly inactivates NO and forms peroxynitrite (ONOO−. It is known that ONOO− accumulates in the placental tissues and injures the placental function in PE. In addition, ROS could stimulate platelet adhesion and aggregation leading to intravascular coagulopathy. ROS-induced coagulopathy causes placental infarction and impairs the uteroplacental blood flow in PE. The disorders could lead to the reduction of oxygen and nutrients required for normal fetal development resulting in fetal growth restriction. On the other hand, several antioxidants scavenge ROS and protect tissues against oxidative damage. Placental antioxidants including catalase, superoxide dismutase (SOD, and glutathione peroxidase (GPx protect the vasculature from ROS and maintain the vascular function. However, placental ischemia in PE decreases the antioxidant activity resulting in further elevated oxidative stress, which leads to the appearance of the pathological conditions of PE including hypertension and proteinuria. Oxidative stress is defined as an imbalance between ROS and antioxidant activity. This review provides new insights about roles of oxidative stress in the pathophysiology of PE.

  17. Mechanisms of hypoxic signal transduction regulated by reactive nitrogen species.

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    Sumbayev, V V; Yasinska, I M

    2007-05-01

    Recent reports devoted to the field of oxygen sensing outline that signalling molecules such as nitric oxide/nitric oxide derived species as well as cytokines and other inflammatory mediators participate in hypoxic signal transduction. In the present review, we summarize the current knowledge about the role of nitric oxide and reactive nitrogen species (RNS) derived from it in hypoxic signal transduction and particularly in accumulation/de-accumulation of hypoxia inducible factor 1 alpha (HIF-1alpha) protein, which is critical not only for cellular adaptation to low oxygen availability but also for generation of inflammatory and innate immune responses. After brief description of nitric oxide and other RNS as multifunctional messengers we analyse and discuss the RNS-dependent accumulation of HIF-1alpha protein under normoxia followed by discussion of the mechanisms of nitric oxide (NO)-dependent enzyme-regulated degradation of HIF-1alpha protein under low oxygen availability.

  18. Nitric oxide and reactive oxygen species mediate metabolic changes in barley seed embryo during germination

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    Zhenguo eMa

    2016-02-01

    Full Text Available The levels of nitric oxide (NO and reactive oxygen species (ROS, ATP/ADP ratios, reduction levels of ascorbate and glutathione, expression of the genes encoding proteins involved in metabolism of NO and activities of the enzymes involved in fermentation and in metabolism of NO and ROS were studied in the embryos of germinating seeds of two barley (Hordeum vulgare L. cultivars differing in dormancy level. The level of NO production continuously increased after imbibition while the level of nitrosylated SH-groups in proteins increased. This corresponded to the decrease of free SH-groups in proteins. At early stage of germination (0-48 h postimbibition the genes encoding class 1 phytoglobin (the protein scavenging NO and S-nitrosoglutathione reductase (scavenging S-nitrosoglutathione were markedly expressed. More dormant cultivar exhibited lower ATP/ADP and ascorbate/dehydroascorbate ratios and lower lactate and alcohol dehydrogenase activities, while the production of NO and nitrosylation of proteins was higher as compared to the non-dormant cultivar. The obtained data indicate that at the onset of germination NO is actively generated causing nitrosylation of SH-groups and a switch from respiration to fermentation. After radicle protrusion the metabolism changes in a more reducing type as recorded by ratio of reduced and oxidized glutathione and ascorbate. The turnover of NO by the scavenging systems (phytoglobin, S-nitrosoglutathione reductase and interaction with ROS might contribute to the maintenance of redox and energy balance of germinating seeds and lead to alleviation of dormancy.

  19. Oleic acid increases mitochondrial reactive oxygen species production and decreases endothelial nitric oxide synthase activity in cultured endothelial cells.

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    Gremmels, Hendrik; Bevers, Lonneke M; Fledderus, Joost O; Braam, Branko; van Zonneveld, Anton Jan; Verhaar, Marianne C; Joles, Jaap A

    2015-03-15

    Elevated plasma levels of free fatty acids (FFA) are associated with increased cardiovascular risk. This may be related to FFA-induced elevation of oxidative stress in endothelial cells. We hypothesized that, in addition to mitochondrial production of reactive oxygen species, endothelial nitric oxide synthase (eNOS)-mediated reactive oxygen species production contributes to oleic acid (OA)-induced oxidative stress in endothelial cells, due to eNOS uncoupling. We measured reactive oxygen species production and eNOS activity in cultured endothelial cells (bEnd.3) in the presence of OA bound to bovine serum albumin, using the CM-H2DCFDA assay and the L-arginine/citrulline conversion assay, respectively. OA induced a concentration-dependent increase in reactive oxygen species production, which was inhibited by the mitochondrial complex II inhibitor thenoyltrifluoroacetone (TTFA). OA had little effect on eNOS activity when stimulated by a calcium-ionophore, but decreased both basal and insulin-induced eNOS activity, which was restored by TTFA. Pretreatment of bEnd.3 cells with tetrahydrobiopterin (BH4) prevented OA-induced reactive oxygen species production and restored inhibition of eNOS activity by OA. Elevation of OA levels leads to both impairment in receptor-mediated stimulation of eNOS and to production of mitochondrial-derived reactive oxygen species and hence endothelial dysfunction. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Nitric oxide increases tolerance responses to moderate water deficit in leaves of Phaseolus vulgaris and Vigna unguiculata bean species.

    Science.gov (United States)

    Zimmer-Prados, Lucas Martins; Moreira, Ana Sílvia Franco Pinheiro; Magalhaes, Jose Ronaldo; França, Marcel Giovanni Costa

    2014-07-01

    Drought stress is one of the most intensively studied and widespread constraints, and nitric oxide (NO) is a key signaling molecule involved in the mediation of abiotic stresses in plants. We demonstrated that a sprayed solution of NO from donor sodium nitroprusside increased drought stress tolerance responses in both sensitive (Phaseolus vulgaris) and tolerant (Vigna unguiculata) beans. In intact plants subjected to halting irrigation, NO increased the leaf relative water content and stomatal conductance in both species. After cutting leaf discs and washing them, NO induced increased electrolyte leakage, which was more evident in the tolerant species. These leaf discs were then subjected to different water deficits, simulating moderate and severe drought stress conditions through polyethylene glycol solutions. NO supplied at moderate drought stress revealed a reduced membrane injury index in sensitive species. In hydrated discs and at this level of water deficit, NO increased the electron transport rate in both species, and a reduction of these rates was observed at severe stress levels. Taken together, it can be shown that NO has an effective role in ameliorating drought stress effects, activating tolerance responses at moderate water deficit levels and in both bean species which present differential drought tolerance.

  1. Dandelion (Taraxacum officinale) flower extract suppresses both reactive oxygen species and nitric oxide and prevents lipid oxidation in vitro.

    Science.gov (United States)

    Hu, C; Kitts, D D

    2005-08-01

    Flavonoids and coumaric acid derivatives were identified from dandelion flower (Taraxacum officinale). Characteristics of chain-breaking antioxidants, such as extended lag phase and reduced propagation rate, were observed in oxidation of linoleic acid emulsion with the addition of dandelion flower extract (DFE). DFE suppressed both superoxide and hydroxyl radical, while the latter was further distinguished by both site-specific and non-specific hydroxyl radical inhibition. DPPH-radical-scavenging activity and a synergistic effect with alpha-tocopherol were attributed to the reducing activity derived from phenolic content of DFE. A significant (p < 0.05) and concentration-dependent, reduced nitric oxide production from acterial-lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells was observed with the addition of DFE. Moreover, peroxyl-radical-induced intracellular oxidation of RAW264.7 cells was inhibited significantly (p < 0.05) by the addition of DFE over a range of concentrations. These results showed that the DFE possessed marked antioxidant activity in both biological and chemical models. Furthermore, the efficacy of DFE in inhibiting both reactive oxygen species and nitric oxide were attributed to its phenolic content.

  2. A Brief Overview of Nitric Oxide and Reactive Oxygen Species Signaling in Hypoxia-Induced Pulmonary Hypertension.

    Science.gov (United States)

    Jaitovich, Ariel; Jourd'heuil, David

    2017-01-01

    Pulmonary hypertension (PH) is characterized by increased vasoconstriction and smooth muscle cell hyperplasia driving pathological vascular remodeling of arterial vessels. In this short review, we discuss the primary source of reactive oxygen species (ROS) and nitric oxide (NO) relevant to PH and the mechanism by which dysregulation of their production contributes to PH. Specifically, hypoxia-induced PH is associated with diminished endothelial nitric oxide synthase (eNOS)-derived NO production and increased production of superoxide (O 2 •- ) through eNOS uncoupling and defective mitochondrial respiration. This drives the inhibition of the NO/soluble guanylate cyclase (sGC) pathway and activation of the transcription factor hypoxia-inducible factor-1α (HIF-1α) with consequential dysregulation of the pulmonary vasculature. Therapeutics aimed at increasing NO or cGMP bioavailabilities are amenable to hypoxia disease-induced PH. Similarly, strategies targeting HIF-1α are now considered. Overall, pulmonary hypertension including hypoxia-induced PH offers unique opportunities for the rational development of therapeutics centered on modulating redox signaling.

  3. Corrosion behavior of stainless steel and zirconium in nitric acid containing highly oxidizing species

    International Nuclear Information System (INIS)

    Mayuzumi, Masami; Fujita, Tomonari

    1994-01-01

    Corrosion behavior of 304ELC, 310Nb stainless steels and Zirconium was investigated in the simulated dissolver solution of a reprocessing plant to obtain fundamental data for life prediction. Corrosion of heat transfer surface was also investigated in nitric acid solutions containing Ce ion. The results obtained are as follows: (1) Stainless steels showed intergranular corrosion in the simulated dissolver solution. The corrosion rate increased with time and reached to a constant value after several hundred hours of immersing time. The constant corrosion rate changed depending on potential suggesting that corrosion potential dominates the corrosion process. 310Nb showed superior corrosion resistance to 304ELC. (2) Corrosion rate of stainless steels increased in the heat transfer condition. The causes of corrosion enhancement are estimated to be higher corrosion potential and higher temperature of heat transfer surface. (3) Zirconium showed perfect passivity in all the test conditions employed. (author)

  4. Expression of inducible and endothelial nitric oxide synthases, formation of peroxynitrite and reactive oxygen species in human chronic renal transplant failure

    NARCIS (Netherlands)

    Albrecht, EWJA; Stegeman, CA; Tiebosch, ATMG; Tegzess, Adam; van Goor, H

    Nitric oxide (NO.) is produced by NO syntheses (NOS) and can interact with reactive oxygen species (ROS) to form peroxynitrite, which induces protein damage by formation of nitrotyrosine. NO. has a promotional effect on acute rejection. To investigate the role of NO. during chronic renal transplant

  5. Scavenging reactive oxygen species using tempol in the acute phase of renal ischemia/reperfusion and its effects on kidney oxygenation and nitric oxide levels

    NARCIS (Netherlands)

    Aksu, Ugur; Ergin, Bulent; Bezemer, Rick; Kandil, Asli; Milstein, Dan M. J.; Demirci-Tansel, Cihan; Ince, Can

    2015-01-01

    Renal ischemia/reperfusion (I/R) injury is commonly seen in kidney transplantation and affects the allograft survival rates. We aimed to test our hypothesis that scavenging reactive oxygen species (ROS) with tempol would protect renal oxygenation and nitric oxide (NO) levels in the acute phase of

  6. Peroxynitrite Chemistry Derived from Nitric Oxide Reaction with a Cu(II)-OOH Species and a new Copper Mediated NO Reductive Coupling Reaction

    Science.gov (United States)

    Kim, Sunghee; Siegler, Maxime A.; Karlin, Kenneth D.

    2014-01-01

    New peroxynitrite-copper chemistry ensues via addition of nitric oxide (•NO(g)) to a CuII-hydroperoxo species. In characterizing the system, the ligand-Cu(I) complex was shown to effect •NO(g) reductive coupling, a new reaction type. Biological implications are discussed. PMID:24322625

  7. Peroxynitrite chemistry derived from nitric oxide reaction with a Cu(II)-OOH species and a copper mediated NO reductive coupling reaction.

    Science.gov (United States)

    Kim, Sunghee; Siegler, Maxime A; Karlin, Kenneth D

    2014-03-18

    New peroxynitrite-copper chemistry ensues via addition of nitric oxide (˙NO(g)) to a Cu(II)-hydroperoxo species. In characterizing the system, the ligand-Cu(i) complex was shown to effect a seldom observed ˙NO(g) reductive coupling reaction. Biological implications are discussed.

  8. Chemistry of extractable nitrosyl ruthenium species in the system nitric acid-tributyl phosphate-dodecane

    International Nuclear Information System (INIS)

    Maya, L.

    1981-01-01

    Fission product ruthenium is present in solutions resulting from the dissolution of spent nuclear fuel in the form of nitro and nitrato complexes of nitrosyl ruthenium. A fraction of the ruthenium, mostly higher nitrato complexes, is extracted into the organic solvent phase in the Purex process. Stripping tests reveal a component in the solvent phase that cannot be readily transferred to the aqueous phase. Experiments were performed to determine whether the retained fraction is a highly extractable species originally present in the aqueous phase or if it is the product of a reaction between the extracted species and the solvent. A chromatographic procedure was developed to separate the species in the aqueous phase. This revealed a species more extractable than the tetranitrato complex; however, since the separation process involved TBP, the ambiguity regarding the origin of this species could not be resolved. On the other hand, in a separate series of experiments evidence was found showing that the retained species result from a reversible reaction in the solvent phase. The equilibrium concentration of this species is dependent on the temperature and the tributyl phosphate activity. This complex apparently results from the substitution of aquo ligands in the extracted species by tributyl phosphate. (author)

  9. Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition

    International Nuclear Information System (INIS)

    Mousset, F.

    2004-12-01

    purpose a dissolution mechanism of RuO 2 ,xH 2 O species in nitric acid as well as quantify, thanks to the determination of oxidation and volatilization apparent constants, the baneful effect of nitrous acid on the electro-volatilization process. An explanation of the low yield of ruthenium electro-volatilization from irradiated fuel solutions has been proposed. (author)

  10. The effect of lipid peroxidation products on reactive oxygen species formation and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages

    Czech Academy of Sciences Publication Activity Database

    Ambrožová, Gabriela; Pekarová, Michaela; Lojek, Antonín

    2011-01-01

    Roč. 25, č. 1 (2011), s. 145-152 ISSN 0887-2333 R&D Projects: GA MŠk(CZ) OC08058; GA ČR(CZ) GA524/08/1753 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : lipid peroxidation products * reactive oxygen species * nitric oxide Subject RIV: BO - Biophysics Impact factor: 2.775, year: 2011

  11. The Role of Reactive Oxygen and Nitrogen Species in the Expression and Splicing of Nitric Oxide Receptor.

    Science.gov (United States)

    Sharina, Iraida G; Martin, Emil

    2017-01-20

    Nitric oxide (NO)-dependent signaling is critical to many cellular functions and physiological processes. Soluble guanylyl cyclase (sGC) acts as an NO receptor and mediates the majority of NO functions. The signaling between NO and sGC is strongly altered by reactive oxygen and nitrogen species. Recent Advances: Besides NO scavenging, sGC is affected by oxidation/loss of sGC heme, oxidation, or nitrosation of cysteine residues and phosphorylation. Apo-sGC or sGC containing oxidized heme is targeted for degradation. sGC transcription and the stability of sGC mRNA are also affected by oxidative stress. Studies cited in this review suggest the existence of compensatory processes that adapt cellular processes to diminished sGC function under conditions of short-term or moderate oxidative stress. Alternative splicing of sGC transcripts is discussed as a mechanism with the potential to both enhance and reduce sGC function. The expression of α1 isoform B, a functional and stable splice variant of human α1 sGC subunit, is proposed as one of such compensatory mechanisms. The expression of dysfunctional splice isoforms is discussed as a contributor to decreased sGC function in vascular disease. Targeting the process of sGC splicing may be an important approach to maintain the composition of sGC transcripts that are expressed in healthy tissues under normal conditions. Emerging new strategies that allow for targeted manipulations of RNA splicing offer opportunities to use this approach as a preventive measure and to control the composition of sGC splice isoforms. Rational management of expressed sGC splice forms may be a valuable complementary treatment strategy for existing sGC-directed therapies. Antioxid. Redox Signal. 26, 122-136.

  12. Nitric oxide and reactive oxygen species coordinately regulate the germination of Puccinia striiformis f. sp. tritici urediniospores

    Directory of Open Access Journals (Sweden)

    Shuining eYin

    2016-02-01

    Full Text Available Nitric oxide (NO and reactive oxygen species (ROS function as signaling molecules in a number of critical signal transduction pathways in plants, including plant biotic interactions. In addition to the role of plant-derived NO and ROS in plant resistance, which has been well documented, pathogen-produced NO and ROS have recently emerged as important players in fungal development and pathogenesis. However, the effects of pathogenic fungi-derived NO and ROS on signaling pathways during fungal pre-infection development remain unknown. Here, using a combination of pharmacological approaches and confocal microscopy, we investigated the roles of NO and ROS during the germination of Puccinia striiformis Westend f. sp. tritici (Pst the wheat stripe rust pathogen. Both NO and ROS have a crucial role in uredinial germination. The scavengers of NO and ROS delayed spore germination and decreased the lengths of germ tubes. A similar phenotype was produced after treatment with the promoter. However, the spores germinated and grew normally when the levels of NO and ROS were simultaneously elevated by the application of a promoter of NO and a donor of ROS. Confocal laser microscopy indicated that both NO and ROS preferentially localized at the germ pores and apexes of growing germ tubes when the ROS/NO ratio in the spores was maintained in a specific range. We concluded that both NO and ROS are critical signaling molecules in the pre-infection development of Pst and that the polar growth of the germ tube is coordinately regulated by NO and ROS.

  13. Reactive oxygen species mediate nitric oxide production through ERK/JNK MAPK signaling in HAPI microglia after PFOS exposure

    International Nuclear Information System (INIS)

    Wang, Cheng; Nie, Xiaoke; Zhang, Yan; Li, Ting; Mao, Jiamin; Liu, Xinhang; Gu, Yiyang; Shi, Jiyun; Xiao, Jing; Wan, Chunhua; Wu, Qiyun

    2015-01-01

    Perfluorooctane sulfonate (PFOS), an emerging persistent contaminant that is commonly encountered during daily life, has been shown to exert toxic effects on the central nervous system (CNS). However, the molecular mechanisms underlying the neurotoxicity of PFOS remain largely unknown. It has been widely acknowledged that the inflammatory mediators released by hyper-activated microglia play vital roles in the pathogenesis of various neurological diseases. In the present study, we examined the impact of PFOS exposure on microglial activation and the release of proinflammatory mediators, including nitric oxide (NO) and reactive oxidative species (ROS). We found that PFOS exposure led to concentration-dependent NO and ROS production by rat HAPI microglia. We also discovered that there was rapid activation of the ERK/JNK MAPK signaling pathway in the HAPI microglia following PFOS treatment. Moreover, the PFOS-induced iNOS expression and NO production were attenuated after the inhibition of ERK or JNK MAPK by their corresponding inhibitors, PD98059 and SP600125. Interestingly, NAC, a ROS inhibitor, blocked iNOS expression, NO production, and activation of ERK and JNK MAPKs, which suggested that PFOS-mediated microglial NO production occurs via a ROS/ERK/JNK MAPK signaling pathway. Finally, by exposing SH-SY5Y cells to PFOS-treated microglia-conditioned medium, we demonstrated that NO was responsible for PFOS-mediated neuronal apoptosis. - Highlights: • PFOS exposure induced expression of iNOS and production of NO in HAPI microglia. • PFOS induced the production of ROS in HAPI microglia. • ERK/JNK MAPK pathways were activated following PFOS exposure in HAPI microglia. • NO released by HAPI microglia participated in the apoptosis of SH-SY5Y cells.

  14. The effect of lipid peroxidation products on reactive oxygen species formation and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages.

    Science.gov (United States)

    Ambrozova, Gabriela; Pekarova, Michaela; Lojek, Antonin

    2011-02-01

    Lipid peroxidation induced by oxidants leads to the formation of highly reactive metabolites. These can affect various immune functions, including reactive oxygen species (ROS) and nitric oxide (NO) production. The aim of the present study was to investigate the effects of lipid peroxidation products (LPPs) - acrolein, 4-hydroxynonenal, and malondialdehyde - on ROS and NO production in RAW 264.7 macrophages and to compare these effects with the cytotoxic properties of LPPs. Macrophages were stimulated with lipopolysaccharide (0.1 μg/ml) and treated with selected LPPs (concentration range: 0.1-100 μM). ATP test, luminol-enhanced chemiluminescence, Griess reaction, Western blotting analysis, amperometric and total peroxyl radical-trapping antioxidant parameter assay were used for determining the LPPs cytotoxicity, ROS and NO production, inducible nitric oxide synthase expression, NO scavenging, and antioxidant properties of LPPs, respectively. Our study shows that the cytotoxic action of acrolein and 4-hydroxynonenal works in a dose- and time-dependent manner. Further, our results imply that acrolein, 4-hydroxynonenal, and malondialdehyde can inhibit, to a different degree, ROS and NO production in stimulated macrophages, partially independently of their toxic effect. Also, changes in enzymatic pathways (especially NADPH-oxidase and nitric oxide synthase inhibition) and NO scavenging properties are included in the downregulation of reactive species formation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. The development of a method for the simultaneous measurement of cerium (IV) and chromium (VI) species in nitric acid media - 16124

    International Nuclear Information System (INIS)

    Nickson, Ian D.; Boxall, Colin; Jackson, Angela; Whillock, Guy O.H.

    2009-01-01

    The corrosion of stainless steel in nitric acid media is a major concern for the nuclear industry. Several reprocessing schemes such as PUREX (Plutonium Uranium Reduction Extraction) and UREX (Uranium Reduction Extraction) utilise nitric acid media, and an understanding of the behaviour of key chemical species in these process streams is vital if their effect on associated corrosion reactions and their rates is to be accurately assessed and quantified. This will allow for more accurate prediction of the working lifetime of any stainless steel surface in contact with the process stream in question. Two such key species that are found in nuclear process streams are cerium as Ce (IV) and chromium as Cr(VI), both of which may act as corrosion accelerants. The redox chemistry of cerium and chromium in highly active liquor (HAL) will depend on nitrous acid concentration, temperature, acidity, total nitrate and possibly the influence of other dissolved species and hence an analytical technique for the on-line measurement of these quantities would be useful for lifetime prediction and corrosion prevention. As a result of this, a strategy for the simultaneous measurement of both Ce(IV) and Cr(VI) species in the presence of other ions typically found in process streams (such as Iron, Magnesium Neodymium and Aluminium) has been developed. The work presented will discuss the design and implementation of the electrochemical techniques that we have used in the development of this strategy and in the measurement of the species in question. (authors)

  16. Insulin Reverses D-Glucose–Increased Nitric Oxide and Reactive Oxygen Species Generation in Human Umbilical Vein Endothelial Cells

    Science.gov (United States)

    González, Marcelo; Rojas, Susana; Avila, Pía; Cabrera, Lissette; Villalobos, Roberto; Palma, Carlos; Aguayo, Claudio; Peña, Eduardo; Gallardo, Victoria; Guzmán-Gutiérrez, Enrique; Sáez, Tamara; Salsoso, Rocío; Sanhueza, Carlos; Pardo, Fabián; Leiva, Andrea; Sobrevia, Luis

    2015-01-01

    Vascular tone is controlled by the L-arginine/nitric oxide (NO) pathway, and NO bioavailability is strongly affected by hyperglycaemia-induced oxidative stress. Insulin leads to high expression and activity of human cationic amino acid transporter 1 (hCAT-1), NO synthesis and vasodilation; thus, a protective role of insulin on high D-glucose–alterations in endothelial function is likely. Vascular reactivity to U46619 (thromboxane A2 mimetic) and calcitonin gene related peptide (CGRP) was measured in KCl preconstricted human umbilical vein rings (wire myography) incubated in normal (5 mmol/L) or high (25 mmol/L) D-glucose. hCAT-1, endothelial NO synthase (eNOS), 42 and 44 kDa mitogen-activated protein kinases (p42/44mapk), protein kinase B/Akt (Akt) expression and activity were determined by western blotting and qRT-PCR, tetrahydrobiopterin (BH4) level was determined by HPLC, and L-arginine transport (0–1000 μmol/L) was measured in response to 5–25 mmol/L D-glucose (0–36 hours) in passage 2 human umbilical vein endothelial cells (HUVECs). Assays were in the absence or presence of insulin and/or apocynin (nicotinamide adenine dinucleotide phosphate-oxidase [NADPH oxidase] inhibitor), tempol or Mn(III)TMPyP (SOD mimetics). High D-glucose increased hCAT-1 expression and activity, which was biphasic (peaks: 6 and 24 hours of incubation). High D-glucose–increased maximal transport velocity was blocked by insulin and correlated with lower hCAT-1 expression and SLC7A1 gene promoter activity. High D-glucose–increased transport parallels higher reactive oxygen species (ROS) and superoxide anion (O2•–) generation, and increased U46619-contraction and reduced CGRP-dilation of vein rings. Insulin and apocynin attenuate ROS and O2•– generation, and restored vascular reactivity to U46619 and CGRP. Insulin, but not apocynin or tempol reversed high D-glucose–increased NO synthesis; however, tempol and Mn(III)TMPyP reversed the high D-glucose–reduced BH4

  17. Transcriptome sequencing of three Pseudo-nitzschia species reveals comparable gene sets and the presence of Nitric Oxide Synthase genes in diatoms.

    Science.gov (United States)

    Di Dato, Valeria; Musacchia, Francesco; Petrosino, Giuseppe; Patil, Shrikant; Montresor, Marina; Sanges, Remo; Ferrante, Maria Immacolata

    2015-07-20

    Diatoms are among the most diverse eukaryotic microorganisms on Earth, they are responsible for a large fraction of primary production in the oceans and can be found in different habitats. Pseudo-nitzschia are marine planktonic diatoms responsible for blooms in coastal and oceanic waters. We analyzed the transcriptome of three species, Pseudo-nitzschia arenysensis, Pseudo-nitzschia delicatissima and Pseudo-nitzschia multistriata, with different levels of genetic relatedness. These species have a worldwide distribution and the last one produces the neurotoxin domoic acid. We were able to annotate about 80% of the sequences in each transcriptome and the analysis of the relative functional annotations allowed comparison of the main metabolic pathways, pathways involved in the biosynthesis of isoprenoids (MAV and MEP pathways), and pathways putatively involved in domoic acid synthesis. The search for homologous transcripts among the target species and other congeneric species resulted in the discovery of a sequence annotated as Nitric Oxide Synthase (NOS), found uniquely in Pseudo-nitzschia multistriata. The predicted protein product contained all the domains of the canonical metazoan sequence. Putative NOS sequences were found in other available diatom datasets, supporting a role for nitric oxide as signaling molecule in this group of microalgae.

  18. Annato extract and β-carotene modulate the production of reactive oxygen species/nitric oxide in neutrophils from diabetic rats

    Science.gov (United States)

    Rossoni-Júnior, Joamyr Victor; Araújo, Glaucy Rodrigues; Pádua, Bruno da Cruz; Chaves, Míriam Martins; Pedrosa, Maria Lúcia; Silva, Marcelo Eustáquio; Costa, Daniela Caldeira

    2012-01-01

    Annatto has been identified as carotenoids that have antioxidative effects. It is well known that one of the key elements in the development of diabetic complications is oxidative stress. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen species and reactive nitrogen species as part of the body’s defense mechanisms to destroy invading pathogens. Reactive oxygen species/reactive nitrogen species are excessively produced by active peripheral neutrophils, and may damage essential cellular components, which in turn can cause vascular complications in diabetes. The present study was undertaken to evaluate the possible protective effects of annatto on the reactive oxygen species and nitric oxide (NO) inhibition in neutrophils from alloxan-induced diabetic rats. Adult female rats were divided into six groups based on receiving either a standard diet with or without supplementation of annatto extract or beta carotene. All animals were sacrificed 30 days after treatment and the neutrophils were isolated using two gradients of different densities. The reactive oxygen species and NO were quantified by a chemiluminescence and spectrophotometric assays, respectively. Our results show that neutrophils from diabetic animals produce significantly more reactive oxygen species and NO than their respective controls and that supplementation with beta carotene and annatto is able to modulate the production of these species. Annatto extract may have therapeutic potential for modulation of the balance reactive oxygen species/NO induced by diabetes. PMID:22573917

  19. Annato extract and β-carotene modulate the production of reactive oxygen species/nitric oxide in neutrophils from diabetic rats.

    Science.gov (United States)

    Rossoni-Júnior, Joamyr Victor; Araújo, Glaucy Rodrigues; Pádua, Bruno da Cruz; Chaves, Míriam Martins; Pedrosa, Maria Lúcia; Silva, Marcelo Eustáquio; Costa, Daniela Caldeira

    2012-05-01

    Annatto has been identified as carotenoids that have antioxidative effects. It is well known that one of the key elements in the development of diabetic complications is oxidative stress. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen species and reactive nitrogen species as part of the body's defense mechanisms to destroy invading pathogens. Reactive oxygen species/reactive nitrogen species are excessively produced by active peripheral neutrophils, and may damage essential cellular components, which in turn can cause vascular complications in diabetes. The present study was undertaken to evaluate the possible protective effects of annatto on the reactive oxygen species and nitric oxide (NO) inhibition in neutrophils from alloxan-induced diabetic rats. Adult female rats were divided into six groups based on receiving either a standard diet with or without supplementation of annatto extract or beta carotene. All animals were sacrificed 30 days after treatment and the neutrophils were isolated using two gradients of different densities. The reactive oxygen species and NO were quantified by a chemiluminescence and spectrophotometric assays, respectively. Our results show that neutrophils from diabetic animals produce significantly more reactive oxygen species and NO than their respective controls and that supplementation with beta carotene and annatto is able to modulate the production of these species. Annatto extract may have therapeutic potential for modulation of the balance reactive oxygen species/NO induced by diabetes.

  20. Scavenging reactive oxygen species using tempol in the acute phase of renal ischemia/reperfusion and its effects on kidney oxygenation and nitric oxide levels

    OpenAIRE

    Aksu, Ugur; Ergin, Bulent; Bezemer, Rick; Kandil, Asli; Milstein, Dan M J; Demirci-Tansel, Cihan; Ince, Can

    2015-01-01

    Background Renal ischemia/reperfusion (I/R) injury is commonly seen in kidney transplantation and affects the allograft survival rates. We aimed to test our hypothesis that scavenging reactive oxygen species (ROS) with tempol would protect renal oxygenation and nitric oxide (NO) levels in the acute phase of renal I/R. Methods Rats were randomly divided: (1) no I/R, no tempol; (2) no I/R, but with tempol; (3) I/R without tempol; and (4) I/R with tempol. I/R was induced by 30-min clamping of th...

  1. Nitric Oxide is Required for Homeostasis of Oxygen and Reactive Oxygen Species in Barley Roots under Aerobic Conditions

    DEFF Research Database (Denmark)

    Gupta, Kapuganti J; Hebelstrup, Kim; Kruger, Nicholas J

    2014-01-01

    Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation...... of mitochondrial metabolism under most conditions, root tissues often suffer oxygen deprivation during normal development due to the lack of an endogenous supply and isolation from atmospheric oxygen. Since changes in oxygen concentration have multiple effects on metabolism and energy production (Geigenberger......, 2003), tight control of oxygen consumption and homeostasis is likely to be particularly important in underground tissues such as roots. Nitric oxide (NO) is involved in many plant processes (Mur et al., 2013) and, under hypoxia, there is good evidence that nitric oxide (NO) contributes to the recycling...

  2. ReaxFF molecular dynamics simulations of intermediate species in dicyanamide anion and nitric acid hypergolic combustion

    International Nuclear Information System (INIS)

    Weismiller, Michael R; Junkermeier, Chad E; Russo, Michael F Jr; Van Duin, Adri C T; Salazar, Michael R; Bedrov, Dmitry

    2015-01-01

    Ionic liquids based on the dicyanamide anion (DCA) are of interest as replacements for current hypergolic fuels, which are highly toxic. To better understand the reaction dynamics of these ionic liquid fuels, this study reports the results of molecular dynamics simulations performed for two predicted intermediate compounds in DCA-based ionic liquids/nitric acid (HNO 3 ) combustion, i.e. protonated DCA (DCAH) and nitro-dicyanamide-carbonyl (NDC). Calculations were performed using a ReaxFF reactive force field. Single component simulations show that neat NDC undergo exothermic decomposition and ignition. Simulations with HNO 3 were performed at both a low (0.25 g ml −1 ) and high (1.00 g ml −1 ) densities, to investigate the reaction in a dense vapor and liquid phase, respectively. Both DCAH and NDC react hypergolically with HNO 3 , and increased density led to shorter times for the onset of thermal runaway. Contrary to a proposed mechanism for DCA combustion, neither DCAH nor NDC are converted to 1,5-Dinitrobiuret (DNB) before thermal runaway. Details of reaction pathways for these processes are discussed. (paper)

  3. Reactive Oxygen Species-Reducing Strategies Improve Pulmonary Arterial Responses to Nitric Oxide in Piglets with Chronic Hypoxia-Induced Pulmonary Hypertension

    Science.gov (United States)

    Dikalova, Anna; Slaughter, James C.; Kaplowitz, M.R.; Zhang, Y.; Aschner, Judy L.

    2013-01-01

    Abstract Aims: There are no effective treatments for chronic pulmonary hypertension in infants with cardiopulmonary disorders associated with hypoxia, such as those with chronic lung disease. These patients often have poor or inconsistent pulmonary dilator responses to inhaled nitric oxide (iNO) therapy for unknown reasons. One possible explanation for poor responsiveness to iNO is reduced NO bioavailability caused by interactions between reactive oxygen species (ROS) and NO. Our major aim was to determine if strategies to reduce ROS improve dilator responses to the NO donor, S-nitroso-N-acetyl-penicillamine (SNAP), in resistance pulmonary arteries (PRAs) from a newborn piglet model of chronic pulmonary hypertension. Results: The dilation to SNAP was significantly impaired in PRAs from piglets with chronic hypoxia-induced pulmonary hypertension. ROS scavengers, including cell-permeable and impermeable agents to degrade hydrogen peroxide (H2O2), improved dilation to SNAP in PRAs from chronically hypoxic piglets. Treatment with agents to inhibit nitric oxide synthase and NADPH oxidase, potential enzymatic sources of ROS, also improved dilation to SNAP in PRAs from hypoxic piglets. Innovation: Our studies are the first to utilize a newborn model of chronic pulmonary hypertension to evaluate the impact of a number of potential therapeutic strategies for ROS removal on responses to exogenous NO in the vessels most relevant to the regulation of pulmonary vascular resistance (PRA). Conclusions: Strategies aimed at reducing ROS merit further evaluation and consideration as therapeutic approaches to improve responses to iNO in infants with chronic pulmonary hypertension. Antioxid. Redox Signal. 18, 1727–1738. PMID:23244497

  4. Effect of chronic apocynin treatment on nitric oxide and reactive oxygen species production in borderline and spontaneous hypertension

    Czech Academy of Sciences Publication Activity Database

    Pecháňová, Olga; Jendeková, L.; Vranková, S.

    2009-01-01

    Roč. 61, č. 1 (2009), s. 116-122 ISSN 1734-1140 Grant - others:VEGA(SK) 2/0178/09; APVV(SK) 0538-07; VEGA(SK) 1/0142/09; APVT(SK) 51-017902; APVV(SK) 0586-06 Institutional research plan: CEZ:AV0Z50110509 Keywords : NO synthase * rective oxygen species * apocynin Subject RIV: ED - Physiology Impact factor: 2.086, year: 2009

  5. Reactive oxygen species up-regulate CD11b in microglia via nitric oxide: Implications for neurodegenerative diseases

    OpenAIRE

    Roy, Avik; Jana, Arundhati; Yatish, Kavitha; Freidt, Matthew B.; Fung, Yiu K.; Martinson, Jeffrey A.; Pahan, Kalipada

    2008-01-01

    Microglial activation is considered as a hallmark of several neurodegenerative disorders. During microglial activation, the expression of CD11b, the beta-integrin marker of microglia, is increased. However, the molecular mechanism behind increased microglial CD11b expression is poorly understood. The present study was undertaken to explore the role of reactive oxygen species (ROS) in the expression of CD11b in microglial cells. Bacterial lipopolysaccharide (LPS) stimulated the expression of C...

  6. Differentiation of cGMP-dependent and -independent nitric oxide effects on platelet apoptosis and reactive oxygen species production using platelets lacking soluble guanylyl cyclase.

    Science.gov (United States)

    Rukoyatkina, N; Walter, U; Friebe, A; Gambaryan, S

    2011-11-01

    Platelet activation is an irreversible process resulting in platelet apoptosis and necrosis, and circulating platelets contain many components of the apoptotic machinery. Cyclic guanosine monophosphate (cGMP) generated by nitric oxide (NO) activated soluble guanylyl cyclase (sGC) plays a crucial role in preventing platelet activation. However, in addition to activation of sGC, cGMP-independent NO effects in platelets have been described. To differentiate between cGMP-dependent and -independent NO effects on platelet apoptosis and reactive oxygen species (ROS) production, we generated platelet-specific sGC-deficient mice (PS-GCKO). Platelet apoptosis was induced by a combination of thrombin/convulxin (Thr/Cvx) and assessed by phosphatidylserine (PS) surface exposure, and loss of the mitochondrial membrane potential. NO-induced inhibition of PS externalisation was mediated only by cGMP-dependent mechanisms. Inhibition of the mitochondrial membrane potential decrease at low NO concentration was also cGMP-dependent but became cGMP-independent at high NO concentrations. In contrast, inhibition of ROS formation at any NO concentration was mediated by cGMP-independent mechanisms, very likely due to direct radical scavenging. NO inhibits platelet apoptosis by cGMP-dependent mechanisms and ROS production by cGMP-independent mechanisms. The PS-GCKO mouse model is an important tool for the differentiation of cGMP-dependent and -independent NO effects on platelets.

  7. Enhanced production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in very long chain saturated fatty acid-accumulated macrophages

    Directory of Open Access Journals (Sweden)

    Kiyanagi Takashi

    2008-11-01

    Full Text Available Abstract Background Deterioration of peroxisomal β-oxidation activity causes an accumulation of very long chain saturated fatty acids (VLCSFA in various organs. We have recently reported that the levels of VLCSFA in the plasma and/or membranes of blood cells were significantly higher in patients with metabolic syndrome and in patients with coronary artery disease than the controls. The aim of the present study is to investigate the effect of VLCSFA accumulation on inflammatory and oxidative responses in VLCSFA-accumulated macrophages derived from X-linked adrenoleukodystrophy (X-ALD protein (ALDP-deficient mice. Results Elevated levels of VLCSFA were confirmed in macrophages from ALDP-deficient mice. The levels of nitric oxide (NO production stimulated by lipopolysaccharide (LPS and interferon-γ (IFN-γ, intracellular reactive oxygen species (ROS, and pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α, interluekin-6 (IL-6, and interleukin-12p70 (IL-12p70, were significantly higher in macrophages from ALDP-deficient mice than in those from wild-type mice. The inducible NO synthase (iNOS mRNA expression also showed an increase in macrophages from ALDP-deficient mice. Conclusion These results suggested that VLCSFA accumulation in macrophages may contribute to the pathogenesis of inflammatory diseases through the enhancement of inflammatory and oxidative responses.

  8. Scavenging reactive oxygen species using tempol in the acute phase of renal ischemia/reperfusion and its effects on kidney oxygenation and nitric oxide levels.

    Science.gov (United States)

    Aksu, Ugur; Ergin, Bulent; Bezemer, Rick; Kandil, Asli; Milstein, Dan M J; Demirci-Tansel, Cihan; Ince, Can

    2015-12-01

    Renal ischemia/reperfusion (I/R) injury is commonly seen in kidney transplantation and affects the allograft survival rates. We aimed to test our hypothesis that scavenging reactive oxygen species (ROS) with tempol would protect renal oxygenation and nitric oxide (NO) levels in the acute phase of renal I/R. Rats were randomly divided: (1) no I/R, no tempol; (2) no I/R, but with tempol; (3) I/R without tempol; and (4) I/R with tempol. I/R was induced by 30-min clamping of the renal artery. Tempol (200 μmol/kg/h/i.v) was administered 15 min prior to I/R. I/R without tempol led to a significant decrease in renal oxygen delivery and microvascular oxygenation. Tempol, however, protected renal oxygenation after I/R. At R90, the creatinine clearance rate was lower in the I/R-subjected group that did not receive tempol compared to that in the other groups. I/R injury without tempol treatment led to a significant increase in tissue malondialdehyde levels and a significant decrease in tissue NO levels. Tempol administration before I/R could prevent oxidative stress and altered tissue NO levels. This underscores that unbalance between oxygen, NO, and ROS forms an important component of the pathogenesis of I/R-induced AKI and should therefore be taken into account when designing a prevention/treatment strategy for renal I/R injury in transplantation.

  9. Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy.

    Science.gov (United States)

    Allen, David G; Whitehead, Nicholas P; Froehner, Stanley C

    2016-01-01

    Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca(2+)-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca(2+) entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease. Copyright © 2016 the American Physiological Society.

  10. When Bad Guys Become Good Ones: The Key Role of Reactive Oxygen Species and Nitric Oxide in the Plant Responses to Abiotic Stress

    Science.gov (United States)

    Farnese, Fernanda S.; Menezes-Silva, Paulo E.; Gusman, Grasielle S.; Oliveira, Juraci A.

    2016-01-01

    The natural environment of plants is composed of a complex set of abiotic stresses and their ability to respond to these stresses is highly flexible and finely balanced through the interaction between signaling molecules. In this review, we highlight the integrated action between reactive oxygen species (ROS) and reactive nitrogen species (RNS), particularly nitric oxide (NO), involved in the acclimation to different abiotic stresses. Under stressful conditions, the biosynthesis transport and the metabolism of ROS and NO influence plant response mechanisms. The enzymes involved in ROS and NO synthesis and scavenging can be found in different cells compartments and their temporal and spatial locations are determinant for signaling mechanisms. Both ROS and NO are involved in long distances signaling (ROS wave and GSNO transport), promoting an acquired systemic acclimation to abiotic stresses. The mechanisms of abiotic stresses response triggered by ROS and NO involve some general steps, as the enhancement of antioxidant systems, but also stress-specific mechanisms, according to the stress type (drought, hypoxia, heavy metals, etc.), and demand the interaction with other signaling molecules, such as MAPK, plant hormones, and calcium. The transduction of ROS and NO bioactivity involves post-translational modifications of proteins, particularly S-glutathionylation for ROS, and S-nitrosylation for NO. These changes may alter the activity, stability, and interaction with other molecules or subcellular location of proteins, changing the entire cell dynamics and contributing to the maintenance of homeostasis. However, despite the recent advances about the roles of ROS and NO in signaling cascades, many challenges remain, and future studies focusing on the signaling of these molecules in planta are still necessary. PMID:27148300

  11. When bad guys become good ones: the key role of reactive oxygen species and nitric oxide in the plant responses to abiotic stress

    Directory of Open Access Journals (Sweden)

    Fernanda Dos Santos Farnese

    2016-04-01

    Full Text Available The natural environment of plants is composed of a complex set of abiotic stresses and their ability to respond to these stresses is highly flexible and finely balanced through the interaction between signaling molecules. In this review, we highlight the integrated action between reactive oxygen species (ROS and reactive nitrogen species (RNS, particularly nitric oxide (NO, involved in the acclimation to different abiotic stresses. Under stressful conditions, the biosynthesis transport and the metabolism of ROS and NO influence plant response mechanisms. The enzymes involved in ROS and NO synthesis and scavenging can be found in different cells compartments and their temporal and spatial locations are determinant for signaling mechanisms. Both ROS and NO are involved in long distances signaling (ROS wave and GSNO transport, promoting an acquired systemic acclimation to abiotic stresses. The mechanisms of abiotic stresses response triggered by ROS and NO involve some general steps, as the enhancement of antioxidant systems, but also stress-specific mechanisms, according to the stress type (drought, hypoxia, heavy metals, etc, and demand the interaction with other signaling molecules, such as MAPK, plant hormones and calcium. The transduction of ROS and NO bioactivity involves post-translational modifications of proteins, particularly S-glutathionylation for ROS, and S-nitrosylation for NO. These changes may alter the activity, stability, and interaction with other molecules or subcellular location of proteins, changing the entire cell dynamics and contributing to the maintenance of homeostasis. However, despite the recent advances about the roles of ROS and NO in signaling cascades, many challenges remain, and future studies focusing on the signaling of these molecules in planta are still necessary.

  12. When Bad Guys Become Good Ones: The Key Role of Reactive Oxygen Species and Nitric Oxide in the Plant Responses to Abiotic Stress.

    Science.gov (United States)

    Farnese, Fernanda S; Menezes-Silva, Paulo E; Gusman, Grasielle S; Oliveira, Juraci A

    2016-01-01

    The natural environment of plants is composed of a complex set of abiotic stresses and their ability to respond to these stresses is highly flexible and finely balanced through the interaction between signaling molecules. In this review, we highlight the integrated action between reactive oxygen species (ROS) and reactive nitrogen species (RNS), particularly nitric oxide (NO), involved in the acclimation to different abiotic stresses. Under stressful conditions, the biosynthesis transport and the metabolism of ROS and NO influence plant response mechanisms. The enzymes involved in ROS and NO synthesis and scavenging can be found in different cells compartments and their temporal and spatial locations are determinant for signaling mechanisms. Both ROS and NO are involved in long distances signaling (ROS wave and GSNO transport), promoting an acquired systemic acclimation to abiotic stresses. The mechanisms of abiotic stresses response triggered by ROS and NO involve some general steps, as the enhancement of antioxidant systems, but also stress-specific mechanisms, according to the stress type (drought, hypoxia, heavy metals, etc.), and demand the interaction with other signaling molecules, such as MAPK, plant hormones, and calcium. The transduction of ROS and NO bioactivity involves post-translational modifications of proteins, particularly S-glutathionylation for ROS, and S-nitrosylation for NO. These changes may alter the activity, stability, and interaction with other molecules or subcellular location of proteins, changing the entire cell dynamics and contributing to the maintenance of homeostasis. However, despite the recent advances about the roles of ROS and NO in signaling cascades, many challenges remain, and future studies focusing on the signaling of these molecules in planta are still necessary.

  13. Mechanical strain stimulates vasculogenesis and expression of angiogenesis guidance molecules of embryonic stem cells through elevation of intracellular calcium, reactive oxygen species and nitric oxide generation.

    Science.gov (United States)

    Sharifpanah, Fatemeh; Behr, Sascha; Wartenberg, Maria; Sauer, Heinrich

    2016-12-01

    Differentiation of embryonic stem (ES) cells may be regulated by mechanical strain. Herein, signaling molecules underlying mechanical stimulation of vasculogenesis and expression of angiogenesis guidance cues were investigated in ES cell-derived embryoid bodies. Treatment of embryoid bodies with 10% static mechanical strain using a Flexercell strain system significantly increased CD31-positive vascular structures and the angiogenesis guidance molecules plexinB1, ephrin B2, neuropilin1 (NRP1), semaphorin 4D (sem4D) and robo4 as well as vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2) and platelet-derived growth factor-BB (PDGF-BB) as evaluated by Western blot and real time RT-PCR. In contrast ephrin type 4 receptor B (EphB4) expression was down-regulated upon mechanical strain, indicating an arterial-type differentiation. Robo1 protein expression was modestly increased with no change in mRNA expression. Mechanical strain increased intracellular calcium as well as reactive oxygen species (ROS) and nitric oxide (NO). Mechanical strain-induced vasculogenesis was abolished by the NOS inhibitor L-NAME, the NADPH oxidase inhibitor VAS2870, upon chelation of intracellular calcium by BAPTA as well as upon siRNA inactivation of ephrin B2, NRP1 and robo4. BAPTA blunted the strain-induced expression of angiogenic growth factors, the increase in NO and ROS as well as the expression of NRP1, sem4D and plexinB1, whereas ephrin B2, EphB4 as well as robo1 and robo4 expression were not impaired. Mechanical strain stimulates vasculogenesis of ES cells by the intracellular messengers ROS, NO and calcium as well as by upregulation of angiogenesis guidance molecules and the angiogenic growth factors VEGF, FGF-2 and PDGF-BB. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Probing the Active Surface Sites for CO Reduction on Oxide-Derived Copper Electrocatalysts

    DEFF Research Database (Denmark)

    Verdaguer Casadevall, Arnau; Li, Christina W.; Johansson, Tobias Peter

    2015-01-01

    CO electroreduction activity on oxide-derived Cu (OD-Cu) was found to correlate with metastable surface features that bind CO strongly. OD-Cu electrodes prepared by H-2 reduction of Cu2O precursors reduce CO to acetate and ethanol with nearly 50% Faradaic efficiency at moderate overpotential. Tem...

  15. Role of reactive nitrogen species generated via inducible nitric oxide synthase in vesicant-induced lung injury, inflammation and altered lung functioning

    Energy Technology Data Exchange (ETDEWEB)

    Sunil, Vasanthi R., E-mail: sunilvr@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy Piscataway, NJ (United States); Shen, Jianliang; Patel-Vayas, Kinal; Gow, Andrew J. [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy Piscataway, NJ (United States); Laskin, Jeffrey D. [Department of Environmental and Occupational Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Laskin, Debra L. [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy Piscataway, NJ (United States)

    2012-05-15

    Pulmonary toxicity induced by sulfur mustard and related vesicants is associated with oxidative stress. In the present studies we analyzed the role of reactive nitrogen species (RNS) generated via inducible nitric oxide synthase (iNOS) in lung injury and inflammation induced by vesicants using 2-chloroethyl ethyl sulfide (CEES) as a model. C57Bl/6 (WT) and iNOS −/− mice were sacrificed 3 days or 14 days following intratracheal administration of CEES (6 mg/kg) or control. CEES intoxication resulted in transient (3 days) increases in bronchoalveolar lavage (BAL) cell and protein content in WT, but not iNOS −/− mice. This correlated with expression of Ym1, a marker of oxidative stress in alveolar macrophages and epithelial cells. In contrast, in iNOS −/− mice, Ym1 was only observed 14 days post-exposure in enlarged alveolar macrophages, suggesting that they are alternatively activated. This is supported by findings that lung tumor necrosis factor and lipocalin Lcn2 expression, mediators involved in tissue repair were also upregulated at this time in iNOS −/− mice. Conversely, CEES-induced increases in the proinflammatory genes, monocyte chemotactic protein-1 and cyclooxygenase-2, were abrogated in iNOS −/− mice. In WT mice, CEES treatment also resulted in increases in total lung resistance and decreases in compliance in response to methacholine, effects blunted by loss of iNOS. These data demonstrate that RNS, generated via iNOS play a role in the pathogenic responses to CEES, augmenting oxidative stress and inflammation and suppressing tissue repair. Elucidating inflammatory mechanisms mediating vesicant-induced lung injury is key to the development of therapeutics to treat mustard poisoning. -- Highlights: ► Lung injury, inflammation and oxidative stress are induced by the model vesicant CEES ► RNS generated via iNOS are important in the CEES-induced pulmonary toxicity ► iNOS −/− mice are protected from CEES-induced lung toxicity and

  16. Role of reactive nitrogen species generated via inducible nitric oxide synthase in vesicant-induced lung injury, inflammation and altered lung functioning

    International Nuclear Information System (INIS)

    Sunil, Vasanthi R.; Shen, Jianliang; Patel-Vayas, Kinal; Gow, Andrew J.; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-01-01

    Pulmonary toxicity induced by sulfur mustard and related vesicants is associated with oxidative stress. In the present studies we analyzed the role of reactive nitrogen species (RNS) generated via inducible nitric oxide synthase (iNOS) in lung injury and inflammation induced by vesicants using 2-chloroethyl ethyl sulfide (CEES) as a model. C57Bl/6 (WT) and iNOS −/− mice were sacrificed 3 days or 14 days following intratracheal administration of CEES (6 mg/kg) or control. CEES intoxication resulted in transient (3 days) increases in bronchoalveolar lavage (BAL) cell and protein content in WT, but not iNOS −/− mice. This correlated with expression of Ym1, a marker of oxidative stress in alveolar macrophages and epithelial cells. In contrast, in iNOS −/− mice, Ym1 was only observed 14 days post-exposure in enlarged alveolar macrophages, suggesting that they are alternatively activated. This is supported by findings that lung tumor necrosis factor and lipocalin Lcn2 expression, mediators involved in tissue repair were also upregulated at this time in iNOS −/− mice. Conversely, CEES-induced increases in the proinflammatory genes, monocyte chemotactic protein-1 and cyclooxygenase-2, were abrogated in iNOS −/− mice. In WT mice, CEES treatment also resulted in increases in total lung resistance and decreases in compliance in response to methacholine, effects blunted by loss of iNOS. These data demonstrate that RNS, generated via iNOS play a role in the pathogenic responses to CEES, augmenting oxidative stress and inflammation and suppressing tissue repair. Elucidating inflammatory mechanisms mediating vesicant-induced lung injury is key to the development of therapeutics to treat mustard poisoning. -- Highlights: ► Lung injury, inflammation and oxidative stress are induced by the model vesicant CEES ► RNS generated via iNOS are important in the CEES-induced pulmonary toxicity ► iNOS −/− mice are protected from CEES-induced lung toxicity and

  17. Nitric oxide supersensitivity

    DEFF Research Database (Denmark)

    Olesen, J; Iversen, Helle Klingenberg; Thomsen, L L

    1993-01-01

    Nitroglycerin, which may be regarded as a prodrug for nitric oxide, induces a mild to moderate headache in healthy subjects. In order to study whether migraine patients are more sensitive to nitric oxide than non-migrainous subjects, four different doses of intravenous nitroglycerin were given...... previously shown a similar supersensitivity to histamine which in human cerebral arteries activates endothelial H1 receptors and causes endothelial production of nitric oxide. Migraine patients are thus supersensitive to exogenous nitric oxide from nitroglycerin as well as to endothelially produced nitric...... oxide. It is suggested that nitric oxide may be partially or completely responsible for migraine pain....

  18. Endothelial Nitric Oxide Synthase Phosphorylation at Threonine 495 and Mitochondrial Reactive Oxygen Species Formation in Response to a High H2O2 Concentration

    DEFF Research Database (Denmark)

    Guterbaum, Thomas Jeremy; Braunstein, Thomas Hartig; Fossum, A

    2013-01-01

    Hydrogen peroxide (H₂O₂) is produced in vessels during ischemia/reperfusion and during inflammation, both leading to vascular dysfunction. We investigated cellular pathways involved in endothelial nitric oxide synthase (eNOS) phosphorylation at Threonine 495 (Thr(495)) in human umbilical vein end...

  19. Expression of TGF-betas and their receptors is differentially modulated by reactive oxygen species and nitric oxide in human articular chondrocytes.

    Science.gov (United States)

    Ayache, N; Boumediene, K; Mathy-Hartert, M; Reginster, J-Y; Henrotin, Y; Pujol, J-P

    2002-05-01

    To study the effects exerted by two antioxidants, N-monomethyl-L-arginine (L-NMMA), as an inhibitor of nitric oxide (NO) synthesis, and N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, on the expression of the major growth factor involved in cartilage repair, TGF-beta, under the three isoforms beta1, beta2 and beta3, and the receptors I and II of this factor, using lipopolysaccharide (LPS)-treated human chondrocytes in culture. Suspension cultures of human chondrocytes derived from the knee of osteoarthritic patients were treated for 48 h with lipopolysaccharide (LPS) (10 microg/ml), L-NMMA (0.5 mM) or NAC (1 mM). Nitrite levels were assayed on the culture media using the Griess spectrophotometric method. After total RNA extraction, the expression of inducible NO synthase (iNOS), TGF-beta1, TGF-beta2, TGF-beta3, TGF-beta receptors I and II, was determined by semi-quantitative polymerase chain-reaction (RT-PCR). LPS induced a dramatic increase of both NO production and iNOS mRNA level. The addition of L-NMMA (0.5 mM) abolished NO production without affecting iNOS mRNA levels. In contrast NAC (1 mM) strongly synergized with LPS to stimulate NO synthesis. LPS treatment did not significantly alter TGF-beta1 expression whereas L-NMMA inhibited its production. TGF-beta2 mRNA level was decreased by LPS and was not changed in the presence of L-NMMA. On the other hand, NAC was capable of counteracting the LPS-induced inhibition of TGF-beta2 expression. TGFbeta3 mRNA level was markedly reduced by LPS alone, or with both L-NMMA and NAC. Finally, the expression of TGF-betaRI was slightly increased in the presence of combined LPS and L-NMMA or NAC whereas that of TGFbeta-RII was reduced in the same conditions. The modulation of TGF-beta system was found to be differentially controlled by NO and ROS productions. Indeed, the control exerted on TGF-beta expression varied according to the isoform: TGF-beta1 mRNA level depends on NO whereas that of TGF-beta2 is

  20. The oxidation of trichloroethylene over different mixed oxides derived from hydrotalcites

    OpenAIRE

    BLANCH RAGA, NEUS; Palomares Gimeno, Antonio Eduardo; Martínez Triguero, Luis Joaquín; Puche Panadero, Marta; Fetter, Geolar; Bosch, Pedro

    2014-01-01

    The activity of different Mg(Fe/Al), Ni(Fe/Al) and Co(Fe/Al) mixed oxides based on hydrotalcite-like compounds have been studied for the catalytic oxidation of trichloroethylene. It has been shown that the Co catalysts are more active than the Ni catalyst, being the Mg catalysts the less active ones. The activity of all the catalysts improves when iron is substituted by aluminum in the catalyst composition. The best results have been obtained with the CoAl mixed oxide derived from...

  1. Indazole N-oxide derivatives as antiprotozoal agents: synthesis, biological evaluation and mechanism of action studies.

    Science.gov (United States)

    Gerpe, Alejandra; Aguirre, Gabriela; Boiani, Lucía; Cerecetto, Hugo; González, Mercedes; Olea-Azar, Claudio; Rigol, Carolina; Maya, Juan D; Morello, Antonio; Piro, Oscar E; Arán, Vicente J; Azqueta, Amaia; de Ceráin, Adela López; Monge, Antonio; Rojas, María Antonieta; Yaluff, Gloria

    2006-05-15

    A series of indazole N-oxide derivatives have been synthesized and their antichagasic and leishmanocidal properties studied. 3-Cyano-2-(4-iodophenyl)-2H-indazole N1-oxide exhibited interesting antichagasic activity on the two parasitic strains and the two parasitic stages evaluated. Furthermore, besides its trypanocidal activity, 3-cyano-2-(4-nitrophenyl)-2H-indazole N1-oxide showed leishmanocidal activity in the three parasitic strains evaluated. To gain insight into the mechanism of action, electrochemical behaviour, ESR experiment, inhibition of parasitic respiration and QSAR were performed.

  2. Annato extract and β-carotene modulate the production of reactive oxygen species/nitric oxide in neutrophils from diabetic rats

    OpenAIRE

    Rossoni-Júnior, Joamyr Victor; Araújo, Glaucy Rodrigues; Pádua, Bruno da Cruz; Chaves, Míriam Martins; Pedrosa, Maria Lúcia; Silva, Marcelo Eustáquio; Costa, Daniela Caldeira

    2011-01-01

    Annatto has been identified asecarotenoids that havetantioxidative effects. It is well known that one of the key elements in the development of diabetic complications is oxidative stress. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen species and reactive nitrogen species as part of the body’s defense mechanisms to destroy invading pathogens. Reactive oxygen species/reactive nitrogen species are excessivel...

  3. Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper

    Science.gov (United States)

    Li, Christina W.; Ciston, Jim; Kanan, Matthew W.

    2014-04-01

    The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel are not available at present. Although many catalysts can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H+ source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products. Here we show that nanocrystalline Cu prepared from Cu2O (`oxide-derived Cu') produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (-0.25 volts to -0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

  4. Ethylene promotes germination of Arabidopsis seed under salinity by decreasing reactive oxygen species: evidence for the involvement of nitric oxide simulated by sodium nitroprusside.

    Science.gov (United States)

    Lin, Yingchao; Yang, Lei; Paul, Matthew; Zu, Yuangang; Tang, Zhonghua

    2013-12-01

    Both ethylene and nitric oxide (NO) are involved in modulating seed germination in adverse environments. However, the mechanisms by which they interact and affect germination have not been explained. In this study, the relationship between ethylene and NO during germination of Arabidopsis seed under salinity was analysed. Application of exogenous 1-aminocyclopropane-1-carboxylate (ACC, a precursor of ethylene biosynthesis) or sodium nitroprusside (SNP, an NO donor) largely overcame the inhibition of germination induced by salinity. The effects of ACC and SNP were decreased by 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (cPTIO), a specific NO scavenger, or by aminoisobutyric acid (AIB), an inhibitor of ethylene biosynthesis, indicating that ethylene and NO interact during germination under salinity. Further, we demonstrated that ACC increased NO production and that SNP greatly induced the expression of the ACS2 gene involved in ethylene synthesis in Arabidopsis seeds germinating under salinity stress, suggesting that each substance influences the production of the other. Application of exogenous ACC increased germination under oxidative stress induced by hydrogen peroxide (H2O2) while SNP had a much smaller effect on wild-type Arabidopsis (Col-0) and no effect on the ethylene insensitive mutant (ein3-1) seeds, respectively. This shows that NO increased germination under salinity indirectly through H2O2 acting via the ethylene pathway. The endogenous concentration of H2O2 was increased by salinity in germinating seeds but was decreased by exogenous ACC, which stimulated germination ultimately. To explain all these results and the regulation of germination of Arabidopsis seed under salinity we propose a model involving ethylene, NO and H2O2 interaction. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  5. Both the stimulation and inhibition of root hair growth induced by extracellular nucleotides in Arabidopsis are mediated by nitric oxide and reactive oxygen species.

    Science.gov (United States)

    Clark, Greg; Wu, Michael; Wat, Noel; Onyirimba, James; Pham, Trieu; Herz, Niculin; Ogoti, Justin; Gomez, Delmy; Canales, Arinda A; Aranda, Gabriela; Blizard, Misha; Nyberg, Taylor; Terry, Anne; Torres, Jonathan; Wu, Jian; Roux, Stanley J

    2010-11-01

    Root hairs secrete ATP as they grow, and extracellular ATP and ADP can trigger signaling pathways that regulate plant cell growth. In several plant tissues the level of extracellular nucleotides is limited in part by ectoapyrases (ecto-NTPDases), and the growth of these tissues is strongly influenced by their level of ectoapyrase expression. Both chemical inhibition of ectoapyrase activity and suppression of the expression of two ectoapyrase enzymes by RNAi in Arabidopsis resulted in inhibition of root hair growth. As assayed by a dose-response curve, different concentrations of the poorly hydrolysable nucleotides, ATPγS and ADPβS, could either stimulate (at 7.5-25 μM) or inhibit (at ≥ 150 μM) the growth rate of root hairs in less than an hour. Equal amounts of AMPS, used as a control, had no effect on root hair growth. Root hairs of nia1nia2 mutants, which are suppressed in nitric oxide (NO) production, and of atrbohD/F mutants, which are suppressed in the production of H(2)O(2), did not show growth responses to applied nucleotides, indicating that the growth changes induced by these nucleotides in wild-type plants were likely transduced via NO and H(2)O(2) signals. Consistent with this interpretation, treatment of root hairs with different concentrations of ATPγS induced different accumulations of NO and H(2)O(2) in root hair tips. Two mammalian purinoceptor antagonists also blocked the growth responses induced by extracellular nucleotides, suggesting that they were initiated by a receptor-based mechanism.

  6. Transcriptome sequencing of three Pseudo-nitzschia species reveals comparable gene sets and the presence of Nitric Oxide Synthase genes in diatoms

    OpenAIRE

    Di Dato, Valeria; Musacchia, Francesco; Petrosino, Giuseppe; Patil, Shrikant; Montresor, Marina; Sanges, Remo; Ferrante, Maria Immacolata

    2015-01-01

    Diatoms are among the most diverse eukaryotic microorganisms on Earth, they are responsible for a large fraction of primary production in the oceans and can be found in different habitats. Pseudo-nitzschia are marine planktonic diatoms responsible for blooms in coastal and oceanic waters. We analyzed the transcriptome of three species, Pseudo-nitzschia arenysensis, Pseudo-nitzschia delicatissima and Pseudo-nitzschia multistriata, with different levels of genetic relatedness. These species hav...

  7. (4+2)-cycloaddition of nitroalkenes with ynamines; formation of a 4H-1,2-oxazine 2-oxide derivative

    NARCIS (Netherlands)

    Pennings, M.L.M.; Reinhoudt, David

    1980-01-01

    The formation of a thermally unstable (4+2)-cycloadduct, a 4H-1,2-oxazine 2-oxide derivative ( ), from the reaction of 1-nitrocyclopentene with 1-phenyl-2-(1-pyrrolidinyl)acetylene has been proven by the structure elucidation of isoxazole derivative which results from thermal rearrangement and by

  8. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide-Derived Copper

    DEFF Research Database (Denmark)

    Bertheussen, Erlend; Verdaguer Casadevall, Arnau; Ravasio, Davide

    2016-01-01

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor...

  9. Sublethal concentrations of salicylic acid decrease the formation of reactive oxygen species but maintain an increased nitric oxide production in the root apex of the ethylene-insensitive never ripe tomato mutants.

    Science.gov (United States)

    Tari, Irma; Poór, Péter; Gémes, Katalin

    2011-09-01

    The pattern of salicylic acid (SA)-induced production of reactive oxygen species (ROS) and nitric oxide (NO) were different in the apex of adventitious roots in wild-type and in the ethylene-insensitive never ripe (Nr) mutants of tomato (Solanum lycopersicum L. cv Ailsa Craig). ROS were upregulated, while NO remained at the control level in apical root tissues of wildtype plants exposed to sublethal concentrations of SA. In contrast, Nr plants expressing a defective ethylene receptor displayed a reduced level of RO S and a higher NO content in the apical root cells. In wild-type plants NO production seems to be RO S(H2O2)-dependent at cell death-inducing concentrations of SA, indicating that ROS and NO may interact to trigger oxidative cell death. In the absence of significant RO S accumulation, the increased NO production caused moderate reduction in cell viability in root apex of Nr plants exposed to 10(-3) M SA. This suggests that a functional ethylene signaling pathway is necessary for the control of ROS and NO production induced by SA.

  10. Mixed oxides derived from layered double hydroxides as novel catalysts for phenol photodegradation

    Science.gov (United States)

    Puscasu, C. M.; Carja, G.; Mureseanu, M.; Zaharia, C.

    2017-08-01

    The removal of organic pollutants is nowadays a very challenging aspect of the environmental research. There are strong interests to develop novel semiconducting photocatalysts able to efficiently promote advanced oxidation reactions. The development of photocatalysts based on the mixtures of mixed oxides derived from layered double hydroxides (LDHs) - a family of naturally occurring anionic clays - might offer novel environmental-friendly solutions for the cost effective removal of organic pollutants. This work presents ZnO/ZnAl2O4, ZnO/Zn2TiO4 and ZnO/ZnCr2O4 as novel photocatalytic formulations for phenol degradation under UV irradiation. They were obtained by the controlled thermal treatment of the layered double hydroxides matrices (LDHs), as precursors materials, type ZnM-LDH (M = Al3+, Cr3+ or Ti4+). The LDHs were synthesized by the co-precipitation method at a constant pH. Controlled calcination at 650°C gives rise to solutions of mixed metal oxides. The structural and nanoarchitectonics characteristics of the studied catalysts were described by: XRD, SEM/TEM and TG/DTG techniques. Results show that in the photocatalytic process of the phenol degradation from aqueous solutions, ZnO/ZnCr2O4 and ZnO/ZnAl2O4 showed the best performance degrading ∼98% of phenol after 3.5 hs and 5 hs, respectively; while ZnO/Zn2TiO4 has degraded almost 80 % after 7.5 hs of UV irradiation. These results open new opportunities in the development of new cost effective photoresponsive formulations able to facilitate the photo-degradation of the organic pollution as “green” solution for removal of dangerous pollutants.

  11. Radiation, nitric oxide and cellular death

    International Nuclear Information System (INIS)

    Dubner, D.; Perez, M.R. Del; Michelin, S.C.; Gisone, P.A.

    1997-01-01

    The mechanisms of radiation induced cellular death constitute an objective of research ever since the first biological effects of radiation were first observed. The explosion of information produced in the last 20 years calls for a careful analysis due to the apparent contradictory data related to the cellular system studied and the range of doses used. This review focuses on the role of the active oxygen species, in particular the nitric oxides, in its relevance as potential mediator of radiation induced cellular death

  12. Bilirubin inhibits the up-regulation of inducible nitric oxide synthase by scavenging reactive oxygen species generated by the toll-like receptor 4-dependent activation of NADPH oxidase

    Directory of Open Access Journals (Sweden)

    Gila Idelman

    2015-08-01

    Full Text Available It has been previously shown that bilirubin prevents the up-regulation of inducible nitric oxide synthase (iNOS in response to LPS. The present study examines whether this effect is exerted through modulation of Toll-Like Receptor-4 (TLR4 signaling. LPS-stimulated iNOS and NADPH oxidase (Nox activity in RAW 264.7 murine macrophages was assessed by measuring cellular nitrate and superoxide (O2− production, respectively. The generation of both nitrate and O2− in response to LPS was suppressed by TLR4 inhibitors, indicating that activation of iNOS and Nox is TLR4-dependent. While treatment with superoxide dismutase (SOD and bilirubin effectively abolished LPS-mediated O2− production, hydrogen peroxide and nitrate release were inhibited by bilirubin and PEG-catalase, but not SOD, supporting that iNOS activation is primarily dependent upon intracellular H2O2. LPS treatment increased nuclear translocation of the redox-sensitive transcription factor Hypoxia Inducible Factor-1α (HIF-1α, an effect that was abolished by bilirubin. Cells transfected with murine iNOS reporter constructs in which the HIF-1α-specific hypoxia response element was disrupted exhibited a blunted response to LPS, supporting that HIF-1α mediates Nox-dependent iNOS expression. Bilirubin, but not SOD, blocked the cellular production of interferon-β, while interleukin-6 production remained unaffected. These data support that bilirubin inhibits the TLR4-mediated up-regulation of iNOS by preventing activation of HIF-1α through scavenging of Nox-derived reactive oxygen species. Bilirubin also suppresses interferon-β release via a ROS-independent mechanism. These findings characterize potential mechanisms for the anti-inflammatory effects of bilirubin.

  13. Bilirubin inhibits the up-regulation of inducible nitric oxide synthase by scavenging reactive oxygen species generated by the toll-like receptor 4-dependent activation of NADPH oxidase.

    Science.gov (United States)

    Idelman, Gila; Smith, Darcey L H; Zucker, Stephen D

    2015-08-01

    It has been previously shown that bilirubin prevents the up-regulation of inducible nitric oxide synthase (iNOS) in response to LPS. The present study examines whether this effect is exerted through modulation of Toll-Like Receptor-4 (TLR4) signaling. LPS-stimulated iNOS and NADPH oxidase (Nox) activity in RAW 264.7 murine macrophages was assessed by measuring cellular nitrate and superoxide ( [Formula: see text] ) production, respectively. The generation of both nitrate and [Formula: see text] in response to LPS was suppressed by TLR4 inhibitors, indicating that activation of iNOS and Nox is TLR4-dependent. While treatment with superoxide dismutase (SOD) and bilirubin effectively abolished LPS-mediated [Formula: see text] production, hydrogen peroxide and nitrate release were inhibited by bilirubin and PEG-catalase, but not SOD, supporting that iNOS activation is primarily dependent upon intracellular H2O2. LPS treatment increased nuclear translocation of the redox-sensitive transcription factor Hypoxia Inducible Factor-1α (HIF-1α), an effect that was abolished by bilirubin. Cells transfected with murine iNOS reporter constructs in which the HIF-1α-specific hypoxia response element was disrupted exhibited a blunted response to LPS, supporting that HIF-1α mediates Nox-dependent iNOS expression. Bilirubin, but not SOD, blocked the cellular production of interferon-β, while interleukin-6 production remained unaffected. These data support that bilirubin inhibits the TLR4-mediated up-regulation of iNOS by preventing activation of HIF-1α through scavenging of Nox-derived reactive oxygen species. Bilirubin also suppresses interferon-β release via a ROS-independent mechanism. These findings characterize potential mechanisms for the anti-inflammatory effects of bilirubin. Copyright © 2015. Published by Elsevier B.V.

  14. A plasma needle generates nitric oxide

    International Nuclear Information System (INIS)

    Stoffels, E; Gonzalvo, Y Aranda; Whitmore, T D; Seymour, D L; Rees, J A

    2006-01-01

    Generation of nitric oxide (NO) by a plasma needle is studied by means of mass spectrometry. The plasma needle is an atmospheric glow generated by a radio-frequency excitation in a mixture of helium and air. This source is used for the treatment of living tissues, and nitric oxide may be one of the most important active agents in plasma therapy. Efficient NO generation is of particular importance in the treatment of cardiovascular diseases. Mass spectrometric measurements have been performed under various plasma conditions; gas composition in the plasma and conversion of feed gases (nitrogen and oxygen) into other species has been studied. Up to 30% of the N 2 and O 2 input is consumed in the discharge, and NO has been identified as the main conversion product

  15. Nitric Oxide: The Wonder Molecule

    Indian Academy of Sciences (India)

    Nitric Oxide: The Wonder Molecule. Kushal Chakraborty is a doctoral student at. Department of Life. Sciences and Biology at. Jadavpur University. Presently he is working on the stimulatory effects of various kinds of NSAIDs on different kinds of cells and isolation of that protein from those cells. Keywords. Nitric oxide ...

  16. Biological nitric oxide signalling: chemistry and terminology

    Science.gov (United States)

    Heinrich, Tassiele A; da Silva, Roberto S; Miranda, Katrina M; Switzer, Christopher H; Wink, David A; Fukuto, Jon M

    2013-01-01

    Biological nitrogen oxide signalling and stress is an area of extreme clinical, pharmacological, toxicological, biochemical and chemical research interest. The utility of nitric oxide and derived species as signalling agents is due to their novel and vast chemical interactions with a variety of biological targets. Herein, the chemistry associated with the interaction of the biologically relevant nitrogen oxide species with fundamental biochemical targets is discussed. Specifically, the chemical interactions of nitrogen oxides with nucleophiles (e.g. thiols), metals (e.g. hemeproteins) and paramagnetic species (e.g. dioxygen and superoxide) are addressed. Importantly, the terms associated with the mechanisms by which NO (and derived species) react with their respective biological targets have been defined by numerous past chemical studies. Thus, in order to assist researchers in referring to chemical processes associated with nitrogen oxide biology, the vernacular associated with these chemical interactions is addressed. PMID:23617570

  17. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M

    2014-01-01

    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed......-nitroso-N-acetylpenicillamine (SNAP) (1) confirmed denitrification as the main NO consumption pathway, with N2O as its major product, (2) showed that denitrification combines one free NO molecule with one NO molecule formed from nitrite to produce N2O, and (3) suggested that NO inhibits N2O reduction....

  18. 49 CFR 173.158 - Nitric acid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nitric acid. 173.158 Section 173.158... Nitric acid. (a) Nitric acid exceeding 40 percent concentration may not be packaged with any other material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as...

  19. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide-Derived Copper

    DEFF Research Database (Denmark)

    Bertheussen, Erlend; Verdaguer Casadevall, Arnau; Ravasio, Davide

    2016-01-01

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor...... product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at −0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline...... solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results represent an important step towards understanding the CO reduction mechanism on OD-Cu electrodes....

  20. Synthesis of quinoxaline 1,4-di-n-oxide derivatives on solid support using room temperature and microwave-assisted solvent-free procedures

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Caro, Lilia C.; Sanchez-Sanchez, Mario; Bocanegra-Garcia, Virgilio; Rivera, Gildardo [Universidad Autonoma de Tamaulipas, Reynosa (Mexico). Dept. de Farmacia y Quimica Medicinal; Monge, Antonio [Universidad de Navarra, Pamplona (Spain). Centro de Investigacion en Farmacobiologia Aplicada. Unidad de Investigacion y Desarrollo de Medicamentos

    2011-07-01

    We describe the synthesis of 12 new ethyl and methyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives on solid supports with room temperature and microwave-assisted solvent-free procedures. Results show that solid supports have good catalytic activity in the formation of quinoxaline 1,4-di-N-oxide derivatives. We found that florisil and montmorillonite KSF and K10 could be used as new, easily available, inexpensive alternatives of catalysts. Additionally, room temperature and microwave-irradiation solvent-free synthesis was more efficient than a conventional procedure (Beirut reaction), reducing reaction time and increasing yield. (author)

  1. Nonenzymatic Reactions above Phospholipid Surfaces of Biological Membranes: Reactivity of Phospholipids and Their Oxidation Derivatives

    Science.gov (United States)

    Solís-Calero, Christian; Ortega-Castro, Joaquín; Frau, Juan; Muñoz, Francisco

    2015-01-01

    Phospholipids play multiple and essential roles in cells, as components of biological membranes. Although phospholipid bilayers provide the supporting matrix and surface for many enzymatic reactions, their inherent reactivity and possible catalytic role have not been highlighted. As other biomolecules, phospholipids are frequent targets of nonenzymatic modifications by reactive substances including oxidants and glycating agents which conduct to the formation of advanced lipoxidation end products (ALEs) and advanced glycation end products (AGEs). There are some theoretical studies about the mechanisms of reactions related to these processes on phosphatidylethanolamine surfaces, which hypothesize that cell membrane phospholipids surface environment could enhance some reactions through a catalyst effect. On the other hand, the phospholipid bilayers are susceptible to oxidative damage by oxidant agents as reactive oxygen species (ROS). Molecular dynamics simulations performed on phospholipid bilayers models, which include modified phospholipids by these reactions and subsequent reactions that conduct to formation of ALEs and AGEs, have revealed changes in the molecular interactions and biophysical properties of these bilayers as consequence of these reactions. Then, more studies are desirable which could correlate the biophysics of modified phospholipids with metabolism in processes such as aging and diseases such as diabetes, atherosclerosis, and Alzheimer's disease. PMID:25977746

  2. Nitrogen isotope exchange between nitric oxide and nitric acid

    International Nuclear Information System (INIS)

    Axente, D.; Abrudean, M.; Baldea, A.

    1996-01-01

    The rate of nitrogen isotope exchange between NO and HNO 3 has been measured as a function of nitric acid concentration of 1.5-4M x 1 -1 . The exchange rate law is shown to be R=k[HNO 3 ] 2 [N 2 O 3 ] and the measured activation energy is E=67.78 kJ x M -1 (16.2 kcal x M -1 ). It is concluded that N 2 O 3 participates in 15 N/ 14 N exchange between NO and HNO 3 at nitric acid concentrations higher than 1.5M x 1 -1 . (author). 7 refs., 3 figs., 4 tabs

  3. Mechanism for excitation-dependent photoluminescence from graphene quantum dots and other graphene oxide derivates: consensus, debates and challenges

    Science.gov (United States)

    Gan, Zhixing; Xu, Hao; Hao, Yanling

    2016-04-01

    Luminescent nanomaterials, with wide applications in biosensing, bioimaging, illumination and display techniques, have been consistently garnering enormous research attention. In particular, those with wavelength-controllable emissions could be highly beneficial. Carbon nanostructures, including graphene quantum dots (GQDs) and other graphene oxide derivates (GODs), with excitation-dependent photoluminescence (PL), which means their fluorescence color could be tuned simply by changing the excitation wavelength, have attracted lots of interest. However the intrinsic mechanism for the excitation-dependent PL is still obscure and fiercely debated presently. In this review, we attempt to summarize the latest efforts to explore the mechanism, including the quantum confinement effect, surface traps model, giant red-edge effect, edge states model and electronegativity of heteroatom model, as well as the newly developed synergistic model, to seek some clues to unravel the mechanism. Meanwhile the controversial difficulties for each model are further discussed. Besides this, the challenges and potential influences of the synthetic methodology and development of the materials are illustrated extensively to elicit more thought and constructive attempts toward their application.

  4. Isoxazole derivatives as new nitric oxide elicitors in plants

    Directory of Open Access Journals (Sweden)

    Anca Oancea

    2017-04-01

    Full Text Available Several 3,5-disubstituted isoxazoles were obtained in good yields by regiospecific 1,3-dipolar cycloaddition reactions between aromatic nitrile oxides, generated in situ from the corresponding hydroxyimidoyl chlorides, with non-symmetrical activated alkynes in the presence of catalytic amounts of copper(I iodide. Effects of 3,5-disubstituted isoxazoles on nitric oxide and reactive oxygen species generation in Arabidopsis tissues was studied using specific diaminofluoresceine dyes as fluorescence indicators.

  5. Anti-Trypanosoma cruzi and anti-leishmanial activity by quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives.

    Science.gov (United States)

    Villalobos-Rocha, Juan Carlos; Sánchez-Torres, Luvia; Nogueda-Torres, Benjamín; Segura-Cabrera, Aldo; García-Pérez, Carlos A; Bocanegra-García, Virgilio; Palos, Isidro; Monge, Antonio; Rivera, Gildardo

    2014-06-01

    In this work, a novel series of ethyl and methyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives were evaluated in vitro on Trypanosoma cruzi trypomastigotes and Leishmania mexicana promastigotes, and cytotoxicity activity in murine macrophages was tested. In silico molecular docking simulations of trypanothione reductase were also done. Three compounds of 33 quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives showed better anti-T. cruzi activity than nifurtimox and beznidazole; two compounds had better anti-leishmanial activity that amphotericin-B, and two compounds showed better activity against both parasites than reference drugs. Compounds M2, M7, M8 and E5, showed low cytotoxic activity on the host cell. The in silico studies suggest that compound M2 is a potential trypanothione reductase inhibitor.

  6. Does Nitric Acid Dissociate at the Aqueous Solution Surface?

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tanza; Winter, Berndt; Stern, Abraham C.; Baer, Marcel D.; Mundy, Christopher J.; Tobias, Douglas J.; Hemminger, J. C.

    2011-11-03

    Nitric acid is a prevalent component of atmospheric aerosols, and the extent of nitric acid dissociation at aqueous interfaces is relevant to its role in heterogeneous atmospheric chemistry. Several experimental and theoretical studies have suggested that the extent of dissociation of nitric acid near aqueous interfaces is less than in bulk solution. Here, dissociation of HNO3 at the surface of aqueous nitric acid is quantified using X-ray photoelectron spectroscopy of the nitrogen local electronic structure. The relative amounts of undissociated HNO3(aq) and dissociated NO3-(aq) are identified by the distinguishable N1s core-level photoelectron spectra of the two species, and we determine the degree of dissociation, αint, in the interface (the first ~3 layers of solution) as a function of HNO3 concentration. Our measurements show that dissociation is decreased by approximately 20% near the solution interface compared with bulk, and furthermore that dissociation occurs even in the top-most solution layer. The experimental results are supported by first-principles MD simulations, which show that hydrogen-bonds between HNO3 and water molecules at the solution surface stabilize the molecular form at low concentration, in analogy to the stabilization of molecular HNO3 that occurs in bulk solution at high concentration. This work was supported by the U.S. Department of Energy's (DOE) Office of Basic Energy Sciences, Chemical Sciences program. The Pacific Northwest National Laboratory is operated by Battelle for DOE.

  7. Dissolution of unirradiated UO2-pellets in nitric acid

    International Nuclear Information System (INIS)

    Herrmann, B.

    1984-02-01

    Cinetics of dissolution of UO 2 -pellets in nitric acid and the gaseous reaction products, N 2 O, NO, NO 2 are determined for different temperatures and acid concentrations. NO 2 :NO ratio increases with temperature and nitrate concentration. The amount of N 2 O formed increases with temperature and acid concentration. At 90 0 C and dissolution in 12 m nitric acid 1l weight-% of UO 2 are dissolved forming N 2 O. The oxidation of UO 2 takes place on the crystal surface or at the interface UO 2 /HNO 3 . U(IV)-ions cannot be detected in the solution. The nitrous acid resulting from reduction of HNO 3 or the species which is in equilibrium with nitrous acid e.g. the nitrosyl-ion is responsible for UO 2 -oxidation. (orig./PW) [de

  8. Nitric oxide and hypoxia signaling.

    Science.gov (United States)

    Jeffrey Man, H S; Tsui, Albert K Y; Marsden, Philip A

    2014-01-01

    Nitric oxide (NO) production is catalyzed by three distinct enzymes, namely, neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). The production of NO by vascular endothelium relies mainly on eNOS. Curiously, iNOS and nNOS also are relevant for vascular NO production in certain settings. By relaxing vascular smooth muscle, the classical view is that NO participates in O2 homeostasis by increasing local blood flow and O2 delivery. It is now appreciated that NO has an even more fundamental role in cellular oxygen sensing at the cellular and physiological level. A key component of cellular oxygen sensing is the hypoxia-inducible factor (HIF) that activates a transcriptional program to promote cellular survival under conditions of inadequate oxygen supply. Important new insights demonstrate that HIF protein is stabilized by two parallel pathways: (1) a decrease in the O2-dependent prolyl hydroxylation of HIF and (2) NO-dependent S-nitrosylation of HIF pathway components including HIF-α. The need for these two complementary pathways to HIF activation arises because decreased oxygen delivery can occur not only by decreased ambient oxygen but also by decreased blood oxygen-carrying capacity, as with anemia. In turn, NO production is tightly linked to O2 homeostasis. O2 is a key substrate for the generation of NO and impacts the enzymatic activity and expression of the enzymes that catalyze the production of NO, the nitric oxide synthases. These relationships manifest in a variety of clinical settings ranging from the unique situation of humans living in hypoxic environments at high altitudes to the common scenario of anemia and the use of therapeutics that can bind or release NO. © 2014 Elsevier Inc. All rights reserved.

  9. Tobacco Xenobiotics Release Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Lam EWN

    2003-09-01

    Full Text Available Abstract Many xenobiotic compounds exert their actions through the release of free radicals and related oxidants 12, bringing about unwanted biological effects 3. Indeed, oxidative events may play a significant role in tobacco toxicity from cigarette smoke. Here, we demonstrate the direct in vitro release of the free radical nitric oxide (•NO from extracts and components of smokeless tobacco, including nicotine, nitrosonornicotine (NNN and 4-(methyl-N-nitrosamino-1-(3-pyridyl-1-butanone (NNK in phosphate buffered saline and human saliva using electron spin resonance and chemiluminescence detection. Our findings suggest that tobacco xenobiotics represent as yet unrecognized sources of •NO in the body.

  10. [Nitric oxide and human aging].

    Science.gov (United States)

    Barbararsh, N A; Kuvshinov, D Iu; Chichilenko, M V; Kolesnikov, A O

    2011-01-01

    More than in 500 17-21-year-old medical students stress reactivity (SR), biological age (BA), arterial pressure (AP) and nitric oxide (NO) metabolites excretion to the alveolar air [nitrates and nitrites concentration (NNC) in alveolar condensate] were determined in rest and before examinations during 1995-2204. AP, BA and NNC were measured in various trimesters of individual year (IY, the period from one person's birthday to another). During this period girls' AP changes insignificantly. The AP of youths is higher than in girls and increases during IV-IY trimester (10-12 months after birthday). The youths NNC decreases from the II to the IV-IY trimesters, but in girls there is a tendency to NNC increase during the IV-IY trimester their NNC negatively correlates (r = -0,34) with their systolic AP Among youths and girls with equal AP, NNC is significantly higher in girls. NNC decreases with the SR rise; this decrease develops during the examination stress too, but in girls NNC decrease is less. BA in youths is higher than in girls and increases during the IV-IY trimester. In youths BA negatively correlates (r = -0,60) with NNC. Taking into mind the "stress theory" of aging (P. Parsons, 1995) our data may be a basis to assumption that nitric oxide is a "molecule of anti-aging".

  11. Relationship between endothelial nitric oxide synthase gene ...

    African Journals Online (AJOL)

    Introduction: Endothelial nitric oxide synthase (eNOS), the enzyme in charge of nitric oxide production, plays a crucial role in vascular biology. However, the impact of single nucleotide polymorphisms (SNPs) affecting the gene encoding for eNOS (eNOS) on coronary artery diseases remains under debate and no data were ...

  12. Resveratrol and Endothelial Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Ning Xia

    2014-10-01

    Full Text Available Nitric oxide (NO derived from the endothelial NO synthase (eNOS has antihypertensive, antithrombotic, anti-atherosclerotic and antiobesogenic properties. Resveratrol is a polyphenol phytoalexin with multiple cardiovascular and metabolic effects. Part of the beneficial effects of resveratrol are mediated by eNOS. Resveratrol stimulates NO production from eNOS by a number of mechanisms, including upregulation of eNOS expression, stimulation of eNOS enzymatic activity and reversal of eNOS uncoupling. In addition, by reducing oxidative stress, resveratrol prevents oxidative NO inactivation by superoxide thereby enhancing NO bioavailability. Molecular pathways underlying these effects of resveratrol involve SIRT1, AMPK, Nrf2 and estrogen receptors.

  13. Analytical Chemistry of Nitric Oxide

    Science.gov (United States)

    Hetrick, Evan M.

    2013-01-01

    Nitric oxide (NO) is the focus of intense research, owing primarily to its wide-ranging biological and physiological actions. A requirement for understanding its origin, activity, and regulation is the need for accurate and precise measurement techniques. Unfortunately, analytical assays for monitoring NO are challenged by NO’s unique chemical and physical properties, including its reactivity, rapid diffusion, and short half-life. Moreover, NO concentrations may span pM to µM in physiological milieu, requiring techniques with wide dynamic response ranges. Despite such challenges, many analytical techniques have emerged for the detection of NO. Herein, we review the most common spectroscopic and electrochemical methods, with special focus on the fundamentals behind each technique and approaches that have been coupled with modern analytical measurement tools or exploited to create novel NO sensors. PMID:20636069

  14. Nitric oxide and chronic colitis

    Directory of Open Access Journals (Sweden)

    Matthew B Grisham

    1996-01-01

    Full Text Available Nitric oxide (NO is thought to play an important role in modulating the inflammatory response by virtue of its ability to affect bloodflow, leukocyte function and cell viability. The objective of this study was to assess the role that NO may play in mediating the mucosal injury and inflammation in a model of chronic granulomatous colitis using two pharmacologically different inhibitors of nitric oxide synthase (NOS. Chronic granulomatous colitis with liver and spleen inflammation was induced in female Lewis rats via the subserosal (intramural injection of peptidoglycan/polysaccharide (PG/PS derived from group A streptococci. Chronic NOS inhibition by oral administration of NG-nitro-L-arginine methyl ester (L-NAME (15 µmol/kg/day or amino-guanidine (AG (15 µmol/ kg/day was found to attenuate the PG/PS-induced increases in macroscopic colonic inflammation scores and colonic myeloperoxidase activity. Only AG -- not L-NAME – attenuated the PG/PS-induced increases in colon dry weight. Both L-NAME and AG significantly attenuated the PG/PS-induced increases in spleen weight whereas neither was effective at significantly attenuating the PG/PS-induced increases in liver weight. Although both L-NAME and AG inhibited NO production in vivo, as measured by decreases in plasma nitrite and nitrate levels, only AG produced significantly lower values (38±3 versus 83±8 µM, respectively, P<0.05. Finally, L-NAME, but not AG, administration significantly increased mean arterial pressure from 83 mmHg in colitic animals to 105 mmHg in the PG/PS+ L-NAME-treated animals (P<0.05. It is concluded that NO may play an important role in mediating some of the pathophysiology associated with this model of chronic granulomatous colitis.

  15. Nitric oxide signaling in hypoxia.

    Science.gov (United States)

    Ho, J J David; Man, H S Jeffrey; Marsden, Philip A

    2012-03-01

    Endothelial-derived nitric oxide (NO) is classically viewed as a regulator of vasomotor tone. NO plays an important role in regulating O(2) delivery through paracrine control of vasomotor tone locally and cardiovascular and respiratory responses centrally. Very soon after the cloning and functional characterization of the endothelial nitric oxide synthase (eNOS), studies on the interaction between O(2) and NO made the paradoxical finding that hypoxia led to decreases in eNOS expression and function. Why would decreases in O(2) content in tissues elicit a loss of a potent endothelial-derived vasodilator? We now know that restricting our view of NO as a regulator of vasomotor tone or blood pressure limited deeper levels of mechanistic insight. Exciting new studies indicate that functional interactions between NO and O(2) exhibit profound complexity and are relevant to diseases states, especially those associated with hypoxia in tissues. NOS isoforms catalytically require O(2). Hypoxia regulates steady-state expression of the mRNA and protein abundance of the NOS enzymes. Animals genetically deficient in NOS isoforms have perturbations in their ability to adapt to changes in O(2) supply or demand. Most interestingly, the intracellular pathways for O(2) sensing that evolved to ensure an appropriate balance of O(2) delivery and utilization intersect with NO signaling networks. Recent studies demonstrate that hypoxia-inducible factor (HIF) stabilization and transcriptional activity is achieved through two parallel pathways: (1) a decrease in O(2)-dependent prolyl hydroxylation of HIF and (2) S-nitrosylation of HIF pathway components. Recent findings support a role for S-nitrosothiols as hypoxia-mimetics in certain biological and/or disease settings, such as living at high altitude, exposure to small molecules that can bind NO, or anemia.

  16. Decomposition of N2O in the nitric acid industry

    International Nuclear Information System (INIS)

    Van den Brink, R.W.; Pieterse, J.A.Z.; Melian-Cabrera, I.; Mul, G.; Kapteijn, F.; Moulijn, J.A.

    2005-03-01

    The nitric acid industry is one of the major sources of the greenhouse gas N2O, which is 310 times more effective than CO2 in trapping heat in the atmosphere. One of the most promising techniques is direct decomposition of N2O in the tail gases of nitric acid plants. The state-of-the-art catalysts are only active at temperatures above 400C, which means that they can be used only in a limited number of plants. The aim of this research is to develop a catalyst that lowers the temperature for N2O decomposition to below 350C. This will increase the number of plants that can use the direct decomposition technique for N2O removal and will improve the cost efficiency for plants with a higher temperature. Many researchers have investigated iron-zeolites in recent years. They are active for N2O decomposition, show a high stability in the tail gases of nitric acid plants and are promoted by the presence of NOx in the tail gases (2,3). Noble metal catalysts for N2O decomposition have been studied less thoroughly than iron zeolites. They show high N2O decomposition activity in in diluted N2O streams, but are inhibited by the oxygen, water and NOx present in nitric acid plant tail gases (4). This paper defines relationships between the structure of iron-zeolite and noble metal catalysts and their activity for N2O decomposition. Several parameters of preparation and post-modification were evaluated for their importance in the formation of active species. Based on the knowledge of the structure activity relations, novel catalysts were found with a higher activity for N2O decomposition than the state-of-the-art catalysts

  17. Mechanisms of neptunium redox reactions in nitric acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sayandev; Bryan, Samuel A.; Casella, Amanda J.; Peterson, James M.; Levitskaia, Tatiana G.

    2017-01-01

    First transuranium element neptunium (Np) exhibits complicated behavior in acidic solutions because it can adopt wide range of oxidation states typically from +3 to +6 and coordinate large variety of ligands. In particular, accurate determination of Np redox potentials in nitric acid solutions is challenging due to overlapping chemical and electrochemical reactions leading to significant experimental uncertainties. Furthermore, over past decades spectrophotometry has been extensively applied to identify and characterize Np solution species in different oxidation states. However, relevant spectral database of Np in nitric acid solutions that can serve for the reference purposes has yet to be established due to the experimental difficulty to isolate and stabilize Np species in pure oxidation states without compromising solution optical properties. This work demonstrates that combination of voltammetry and controlled-potential in situ thin-layer spectropotentiometry overcomes these challenges so that Np species in pure +3, +4, +5, or +6 oxidation states were electrochemically generated in the systematically varied 0.1 – 5 M nitric acid solutions, and corresponding vis-NIR spectral signatures were obtained. In situ optical monitoring of the interconversion between adjacent Np oxidation states resulted in elucidation of the mechanisms of the involved redox reactions, in-depth understanding of the relative stability of the Np oxidation states, and allowed benchmarking of the redox potentials of the NpO22+/NpO2+, NpO2+/Np4+ and Np4+/Np3+ couples. Notably, the NpO2+/Np4+ couple was distinguished from the proximal Np4+/Np3+ process overcoming previous concerns and challenges encountered in accurate determination of the respective potentials.

  18. Extraction and Separation of Lanthanum (III) and Neodymium (III) from Nitric acid by Aliquat-336 in Kerosene

    International Nuclear Information System (INIS)

    Ahmed, M.I.; Ali, M.I.; EI-Dessouky, S.I.; Daoud, J.A.; Aly, H.F.; Abd EI-Rehim, S.S.

    2010-01-01

    Aliquat-336 (tricapryl methyl ammonium chloride) in kerosene was used as an extractant for La (Ill) and Nd (Ill) from nitric acid medium. The different parameters affecting the extraction of the investigated metal ions such as hydrogen ion concentration, nitric acid, Aliquat-336 concentration, metal ion, loading capacity as well as temperature were separately investigated. The extraction of both cations was found to increase with increasing Aliquat-336, metal ion, nitrate and nitric acid concentration, while it decreases slightly with hydrogen ion concentration. The stoichiometry of the extracted metal species investigated was found to be M (NO 3 ) - 4 L + for both cations. The thermodynamic functions were determined and discussed. The stripping of the extracted metal species by nitric, sulphuric, hydrochloric acids and sodium hydroxide were carried out. The difference in the extraction and stripping conditions was used for the separation of La (III) and Nd (Ill) from aqueous nitrate medium.

  19. [Higher nitric oxide levels are associated with disease activity in Egyptian rheumatoid arthritis patients].

    Science.gov (United States)

    Ali, Adel Mahmoud; Habeeb, Reem Abdelmonem; El-Azizi, Noran Osama; Khattab, Dina Aziz; Abo-Shady, Rania Ahmed; Elkabarity, Rania Hamdy

    2014-01-01

    Oxidative stress generated within inflammatory joints can produce autoimmune phenomena and joint destruction. Radical species with oxidative activity, including reactive nitrogen species, represent mediators of inflammation and cartilage damage. To assess serum nitric oxide as a marker of oxidative stress in Egyptian patients with rheumatoid arthritis and its relation to disease activity. 80 patients with rheumatoid arthritis were divided into 2 groups, according to the DAS-28 score: Group I: 42 patients with disease activity, and Group II: 38 patients with no disease activity. Forty age- and sex-matched individuals were included as control group (Group III). Routine laboratory investigations were done, and nitric oxide was measured using Elisa. Hand plain radiographies were done for radiological status scoring using the Sharp method. A comparison between nitric oxide in all three groups showed a highly significant difference (p < 0.001), significantly higher levels were obtained among rheumatoid arthritis patients in comparison to controls, and higher levels were obtained in patients with active disease (mean±SD 82.38±20.46) in comparison to patients without active disease (35.53±7.15). Nitric oxide in Group I showed a significant positive correlation with morning stiffness (r=0.45), arthritis (r=0.43), platelet count (r=0.46), erythrocyte sedimentation rate (r=0.83), C-reactive protein (r=0.76) and Disease Activity Score (r=0.85). Nitric oxide showed a significant positive correlation (r=0.43) with hand radiographies (Sharp score) in Group I. There are increased levels of nitric oxide in the serum of patients with rheumatoid arthritis. Nitric oxide correlates significantly with disease activity, inflammatory markers and radiological joint status. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  20. Increasing the Fungicidal Action of Amphotericin B by Inhibiting the Nitric Oxide-Dependent Tolerance Pathway

    Directory of Open Access Journals (Sweden)

    Kim Vriens

    2017-01-01

    Full Text Available Amphotericin B (AmB induces oxidative and nitrosative stresses, characterized by production of reactive oxygen and nitrogen species, in fungi. Yet, how these toxic species contribute to AmB-induced fungal cell death is unclear. We investigated the role of superoxide and nitric oxide radicals in AmB’s fungicidal activity in Saccharomyces cerevisiae, using a digital microfluidic platform, which enabled monitoring individual cells at a spatiotemporal resolution, and plating assays. The nitric oxide synthase inhibitor L-NAME was used to interfere with nitric oxide radical production. L-NAME increased and accelerated AmB-induced accumulation of superoxide radicals, membrane permeabilization, and loss of proliferative capacity in S. cerevisiae. In contrast, the nitric oxide donor S-nitrosoglutathione inhibited AmB’s action. Hence, superoxide radicals were important for AmB’s fungicidal action, whereas nitric oxide radicals mediated tolerance towards AmB. Finally, also the human pathogens Candida albicans and Candida glabrata were more susceptible to AmB in the presence of L-NAME, pointing to the potential of AmB-L-NAME combination therapy to treat fungal infections.

  1. Physiological responses of lichens to factorial fumigations with nitric acid and ozone

    Science.gov (United States)

    J. Riddell; P.E. Padgett; T. Nash

    2012-01-01

    This paper addresses the effects of gaseous nitric acid (HNO3) and ozone (O3), two important air pollutants, on six lichen species with different morphological, ecological, and biological characteristics. The treatment chambers were set up in a factorial design consisting of control chambers, chambers fumigated with HNO

  2. Nitric Oxide Gene Therapy for Prostate Cancer

    National Research Council Canada - National Science Library

    Armour, Elwood

    1999-01-01

    .... One approach to therapy is over-production of inducible nitric oxide synthase (iNOS) within the tumor by injecting replication defective adenovirus containing the DNA sequences for iNOS into prostate tumors...

  3. Flavonoids as scavengers of nitric oxide radical.

    NARCIS (Netherlands)

    van Acker, S.A.B.E.; Tromp, M.N.J.L.; Haenen, G.R.M.M.; van der Vijgh, W.J.F.; Bast, A.

    1995-01-01

    Flavonoids are a group of naturally occurring compounds used, e.g., in the treatment of vascular endothelial damage. They are known to be excellent scavengers of oxygen free radicals. Since the nitric oxide radical (

  4. Image analysis of epicuticular damage to foliage caused by dry deposition of the air pollutant nitric acid.

    Science.gov (United States)

    Padgett, Pamela E; Parry, Sally D; Bytnerowicz, Andrzej; Heath, Robert L

    2009-01-01

    Nitric acid vapor is produced by the same photochemical processes that produce ozone. In the laboratory, concentrated nitric acid is a strong acid and a powerful oxidant. In the environment, where the concentrations are much lower, it is an innocuous source of plant nitrogen. As an air pollutant, which mode of action does dry deposition of nitric acid follow? We investigated the effects of dry deposition of nitric acid on the foliage of four tree species native to the western United States. A novel controlled environment, fumigation system enabled a four-week exposure at concentrations consistent with ambient diurnal patterns. Scanning electron microscopy and automated image analysis revealed changes in the epicuticular wax layer during fumigation. Exposure to nitric acid resulted in a reproducible suite of damage symptoms that increased with increasing dose. Each tree species tested exhibited a unique set of damage features, including cracks, lesions, and conformation changes to epicuticular crystallite structures. Dry deposition of atmospheric nitric acid caused substantial perturbation to the epicuticular surface of all four tree species investigated, consistent with the chemical oxidation of epicuticular waxes. Automated image analysis eliminated many biases that can trouble microscopy studies. Trade names and commercial enterprises or products are mentioned solely for information. No endorsements by the U.S. Department of Agriculture are implied.

  5. Electro-volatilization of ruthenium in nitric medium: influences of ruthenium species nature and models solutions composition; Electro-volatilisation du ruthenium en milieu nitrique: influence de la nature des formes chimiques du ruthenium et de la composition des solutions modeles de dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Mousset, F

    2004-12-15

    extent, an electro-eater behaviour as well as Pu{sup 4+} and Cr{sup 3+} according to the thermodynamics data. These results allow one to purpose a dissolution mechanism of RuO{sub 2},xH{sub 2}O species in nitric acid as well as quantify, thanks to the determination of oxidation and volatilization apparent constants, the baneful effect of nitrous acid on the electro-volatilization process. An explanation of the low yield of ruthenium electro-volatilization from irradiated fuel solutions has been proposed. (author)

  6. Studies on the solvent extraction behaviour of Pu(IV) from nitric acid, nitric-perchloric acid and hydrochloric acids, by di,2-ethylhexyl phosphoric acid (HDEHP)

    International Nuclear Information System (INIS)

    Phal, D.G.; Kannan, S.K.; Ramakrishna, V.V.

    1994-01-01

    Extraction of plutonium (IV) from aqueous nitric acid, nitric-perchloric acid and hydrochloric acids by di,2-ethylhexyl phosphoric acid, the dimeric form of which is represented as H 2 Y 2 , in different diluents (dodecane, toluene and chloroform) was investigated. The composition of the extracted Pu(IV) species were found to be Pu(NO 3 ) 2 (HY) 2 , Pu(NO 3 )(ClO 4 )(HY 2 ) 2 , PuClY(HY 2 ) 2 and PuCl 2 (HY 2 ) 2 from nitric, nitric-perchloric and hydrochloric acids respectively, the last one being pre-dominant at high aqueous acidities (i.e. 5M HCl). Synergic enhancement in the extraction of Pu(IV) from different aqueous media, by the addition of thenoyltrifluoroacetone (HTTA) to HDEHP was also investigated and was attributed to the formation and extraction of the species PuX(TTA)(HY 2 ) 2 , and Pu(TTA) 2 (HY 2 ) 2 where X=Cl - or NO 3 - . The addition of the neutral extractant TOPO to H 2 Y 2 also resulted in synergism. The possible equilibria in these systems were inferred and the corresponding equilibrium constants determined. (author). 24 refs., 10 figs., 10 tabs

  7. THE ESTROGENS / CHROMIUM INTERACTION IN THE NITRIC OXIDE GENERATION.

    Science.gov (United States)

    Sawicka, Ewa; Piwowar, Agnieszka; Musiala, Tomasz; Dlugosz, Anna

    2017-05-01

    The interaction of estrogens with environmental toxins in free radicals generation: reactive oxygen species (ROS) or reactive nitrogen species (RNS) which participates in cancerogenesis is not yet recognized. Chromium(VI) is widely present in environment. One of its toxicity pathway is free radicals generation. Estrogens have the ability to scavenge free radicals, but may also act as prooxidants. Both chromium(VI) and estrogens are classified by International Agency for Research on Cancer (IARC) as carcinogens, so synergistic effect seems very dangerous. The interaction of chromium and estrogens in ROS generation are partly described but there are no reports on estrogen/chromium interaction on nitric oxide (NO) generation. The aim of the study was to examine the interaction of chromium(VI) and 17-p-estradiol (E2) on NO level in human blood as well as the role of E2 metabolites: 4-hydroxyestradiol (4-OHE2) and 16a-hydroxyestrone (16α-OHE1) in these processes. The NO level was estimated with the diagnostic kit (Nitric Oxide Colorimetric Detection Kit from Arbor Assays) in human blood in vitm. The results showed that Cr(VI) in used concentration (0.5; 1.0 and 5.0 gg/mL) decreases significantly NO level in blood, acting antagonistically to E2 and 4-OHE2. Estrogens (E2, 4-OHE2 and 16α-OHEI) do not protect against inhibiting effect of Cr(VI) on nitric oxide generation in blood because after combined exposure the decreased production of NO in blood was noted. In conclusion, presented results provide the information about the character of estrogen/Cr(VI) interaction in NO level in human blood. It is important knowledge for cardio protected effect e.g., hormone replacement therapy in environmental or occupational exposure to Cr(VI), chromium supplementation, also important for cancer risk evaluation.

  8. Nitric oxide in cancer metastasis.

    Science.gov (United States)

    Cheng, Huiwen; Wang, Lei; Mollica, Molly; Re, Anthony T; Wu, Shiyong; Zuo, Li

    2014-10-10

    Cancer metastasis is the spread and growth of tumor cells from the original neoplasm to further organs. This review analyzes the role of nitric oxide (NO), a signaling molecule, in the regulation of cancer formation, progression, and metastasis. The action of NO on cancer relies on multiple factors including cell type, metastasis stage, and organs involved. Various chemotherapy drugs cause cells to release NO, which in turn induces cytotoxic death of breast, liver, and skin tumors. However, NO has also been clinically connected to a poor cancer prognosis because of its role in angiogenesis and intravasation. This supports the claim that NO can be characterized as both pro-metastatic and anti-metastatic, depending on specific factors. The inhibition of cell proliferation and anti-apoptosis pathways by NO donors has been proposed as a novel therapy to various cancers. Studies suggest that NO-releasing non-steroidal anti-inflammatory drugs act on cancer cells in several ways that may make them ideal for cancer therapy. This review summarizes the biological significance of NO in each step of cancer metastasis, its controversial effects for cancer progression, and its therapeutic potential. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. The extraction thermodynamics of uranium (VI) from nitric acid solution by N-octanoyl piperidine

    International Nuclear Information System (INIS)

    Bao Borong; Shao Hua; Han Jingtian; Yang Yonghui; Sun Sixiu

    2002-01-01

    The extraction thermodynamics of uranium (VI) from nitric acid solution by N-octanoyl piperidine in toluene was investigated. The results showed that two extracted species of UO 2 (NO 3 ) 2 (OP) and UO 2 (NO 3 ) 2 (OP) 2 were formed, and the equilibrium constants were K ex1 = 0.538 and K ex2 = 4.230 respectively. Through considering the sub-reaction of extraction, the equilibrium constant of extracting nitric acid with N-octanoyl piperidine were obtained to be K HNO 3 = 0.097

  10. Nitric oxide in cerebral vasospasm: theories, measurement, and treatment.

    Science.gov (United States)

    Siuta, Michael; Zuckerman, Scott L; Mocco, J

    2013-01-01

    In recent decades, a large body of research has focused on the role of nitric oxide (NO) in the development of cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH). Literature searches were therefore conducted regarding the role of NO in cerebral vasospasm, specifically focusing on NO donors, reactive nitrogen species, and peroxynitrite in manifestation of vasospasm. Based off the assessment of available evidence, two competing theories are reviewed regarding the role of NO in vasospasm. One school of thought describes a deficiency in NO due to scavenging by hemoglobin in the cisternal space, leading to an NO signaling deficit and vasospastic collapse. A second hypothesis focuses on the dysfunction of nitric oxide synthase, an enzyme that synthesizes NO, and subsequent generation of reactive nitrogen species. Both theories have strong experimental evidence behind them and hold promise for translation into clinical practice. Furthermore, NO donors show definitive promise for preventing vasospasm at the angiographic and clinical level. However, NO augmentation may also cause systemic hypotension and worsen vasospasm due to oxidative distress. Recent evidence indicates that targeting NOS dysfunction, for example, through erythropoietin or statin administration, also shows promise at preventing vasospasm and neurotoxicity. Ultimately, the role of NO in neurovascular disease is complex. Neither of these theories is mutually exclusive, and both should be considered for future research directions and treatment strategies.

  11. Nitric Oxide in Cerebral Vasospasm: Theories, Measurement, and Treatment

    Directory of Open Access Journals (Sweden)

    Michael Siuta

    2013-01-01

    Full Text Available In recent decades, a large body of research has focused on the role of nitric oxide (NO in the development of cerebral vasospasm (CV following subarachnoid hemorrhage (SAH. Literature searches were therefore conducted regarding the role of NO in cerebral vasospasm, specifically focusing on NO donors, reactive nitrogen species, and peroxynitrite in manifestation of vasospasm. Based off the assessment of available evidence, two competing theories are reviewed regarding the role of NO in vasospasm. One school of thought describes a deficiency in NO due to scavenging by hemoglobin in the cisternal space, leading to an NO signaling deficit and vasospastic collapse. A second hypothesis focuses on the dysfunction of nitric oxide synthase, an enzyme that synthesizes NO, and subsequent generation of reactive nitrogen species. Both theories have strong experimental evidence behind them and hold promise for translation into clinical practice. Furthermore, NO donors show definitive promise for preventing vasospasm at the angiographic and clinical level. However, NO augmentation may also cause systemic hypotension and worsen vasospasm due to oxidative distress. Recent evidence indicates that targeting NOS dysfunction, for example, through erythropoietin or statin administration, also shows promise at preventing vasospasm and neurotoxicity. Ultimately, the role of NO in neurovascular disease is complex. Neither of these theories is mutually exclusive, and both should be considered for future research directions and treatment strategies.

  12. Changes in the level of cytosolic calcium, nitric oxide and nitric oxide ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR G

    and its prolongation by aspirin; Blood 34 204–215. Moncada S, Palmer R M and Higgs E A 1991 Nitric oxide: physiology, pathophysiology and pharmacology; Pharmacol. Rev. 43 109–142. Ni Z, Wang X Q and Vaziri N D 1998 Nitric oxide metabolism in erythropoietin-induced hypertension: effect of calcium channel.

  13. Expression of the nos gene and Firefly Flashing: A Test of the Nitric-Oxide-Mediated Flash Control Model

    OpenAIRE

    Ohtsuki, Hajime; Yokoyama, Jun; Ohba, Nobuyoshi; Ohmiya, Yoshihiro; Kawata, Masakado

    2014-01-01

    Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and populations of the same species. Their lights are assumed to be biological properties that play important ecological and evolutionary roles. Some species in the Lampyridae emit periodic luminescence, the patterns of which are characterized by species-specific intervals. In previous work, it was predicted that the nitric oxide (NO) regulates the oxygen supply required for the bioluminescence reaction o...

  14. Nitric oxide and mitochondrial respiration.

    Science.gov (United States)

    Brown, G C

    1999-05-05

    Nitric oxide (NO) and its derivative peroxynitrite (ONOO-) inhibit mitochondrial respiration by distinct mechanisms. Low (nanomolar) concentrations of NO specifically inhibit cytochrome oxidase in competition with oxygen, and this inhibition is fully reversible when NO is removed. Higher concentrations of NO can inhibit the other respiratory chain complexes, probably by nitrosylating or oxidising protein thiols and removing iron from the iron-sulphur centres. Peroxynitrite causes irreversible inhibition of mitochondrial respiration and damage to a variety of mitochondrial components via oxidising reactions. Thus peroxynitrite inhibits or damages mitochondrial complexes I, II, IV and V, aconitase, creatine kinase, the mitochondrial membrane, mitochondrial DNA, superoxide dismutase, and induces mitochondrial swelling, depolarisation, calcium release and permeability transition. The NO inhibition of cytochrome oxidase may be involved in the physiological regulation of respiration rate, as indicated by the finding that isolated cells producing NO can regulate cellular respiration by this means, and the finding that inhibition of NO synthase in vivo causes a stimulation of tissue and whole body oxygen consumption. The recent finding that mitochondria may contain a NO synthase and can produce significant amounts of NO to regulate their own respiration also suggests this regulation may be important for physiological regulation of energy metabolism. However, definitive evidence that NO regulation of mitochondrial respiration occurs in vivo is still missing, and interpretation is complicated by the fact that NO appears to affect tissue respiration by cGMP-dependent mechanisms. The NO inhibition of cytochrome oxidase may also be involved in the cytotoxicity of NO, and may cause increased oxygen radical production by mitochondria, which may in turn lead to the generation of peroxynitrite. Mitochondrial damage by peroxynitrite may mediate the cytotoxicity of NO, and may be

  15. Thermodynamic and kinetic modelling of the reduction of concentrated nitric acid

    International Nuclear Information System (INIS)

    Sicsic, David

    2011-01-01

    This research thesis aimed at determining and quantifying the different stages of the reduction mechanism in the case of concentrated nitric acid. After having reported the results of a bibliographical study on the chemical and electrochemical behaviour of concentrated nitric media (generalities, chemical equilibriums, NOx reactivity, electrochemical reduction of nitric acid), the author reports the development and discusses the results of a thermodynamic simulation of a nitric environment at 25 C. This allowed the main species to be identified in the liquid and gaseous phases of nitric acid solutions. The author reports an experimental electrochemical investigation coupled with analytic techniques (infrared and UV-visible spectroscopy) and shows that the reduction process depends on the cathodic overvoltage, and identifies three potential areas. A kinetic modelling of the stationary state and of the impedance is then developed in order to better determine, discuss and quantify the reduction process. The application of this kinetic model to the preliminary results of an electrochemical study performed on 304 L steel is then discussed [fr

  16. Curcumin overcomes the inhibitory effect of nitric oxide on Leishmania.

    Science.gov (United States)

    Chan, Marion Man-Ying; Adapala, Naga Suresh; Fong, Dunne

    2005-04-01

    Upon Leishmania infection, macrophages are activated to produce nitrogen and oxygen radicals simultaneously. It is well established that the infected host cells rely on nitric oxide (NO) as the major weapon against the intracellular parasite. In India where leishmaniasis is endemic, the spice turmeric is used prolifically in food and for insect bites. Curcumin, the active principle of turmeric, is a scavenger of NO. This report shows that curcumin protects promastigotes and amastigotes of the visceral species, Leishmania donovani, and promastigotes of the cutaneous species, L. major, against the actions of S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETANONOate, which release NO, 3-morpholino-sydnonimine hydrochloride (SIN-1), which releases NO and superoxide, and peroxynitrite, which is formed from the reaction of NO with superoxide. Thus, curcumin, as an antioxidant, is capable of blocking the action of both NO and NO congeners on the Leishmania parasite.

  17. Physiological responses of lichens to factorial fumigations with nitric acid and ozone

    International Nuclear Information System (INIS)

    Riddell, J.; Padgett, P.E.; Nash, T.H.

    2012-01-01

    This paper addresses the effects of gaseous nitric acid (HNO 3 ) and ozone (O 3 ), two important air pollutants, on six lichen species with different morphological, ecological, and biological characteristics. The treatment chambers were set up in a factorial design consisting of control chambers, chambers fumigated with HNO 3 , with O 3 , and with HNO 3 and O 3 , together. Each species showed a different sensitivity to the fumigations, reflecting the physiological variation among species. Our results clearly indicate that HNO 3 is a strong phytotoxin to many lichens, and that O 3 alone has little effect on the measured parameters. The combined fumigation effects of HNO 3 and O 3 were not significantly different from HNO 3 alone. - Highlights: ► We fumigated 6 lichen species with factorial combinations of nitric acid (HNO 3 ) and ozone (O 3 ). ► Some species were highly sensitive to HNO 3 while others were tolerant. ► No species responded significantly to O 3 . ► The combined fumigation effects of HNO 3 and O 3 were not significantly different from HNO 3 alone. ► HNO 3 may play an important role in lichen community composition in areas with high HNO 3 pollution. - Nitric acid can be highly toxic to lichens through several physiological mechanisms. Ozone is relatively non-toxic to fumigated lichens.

  18. N,N,N',N'-tetrabutyladipicamide as a new extractant in toluene of nitric acid and uranium(VI)

    International Nuclear Information System (INIS)

    Wang, Y.S.; Tan, X.F.; Shen, C.H.; Bao, B.R.

    1999-01-01

    N,N,N',N'-Tetrabutyladipicamide (TBAA) was used for the extraction of nitric acid and uranyl(II) ion from nitric acid media into toluene. The effects of nitric acid, uranyl(II) ion, and extractant concentration, temperature and back extraction on the distribution coefficient of uranyl(II) ion have been studied. The main adduct of TBAA and HNO 3 is TBAA-HNO 3 in 1.0 mol/l nitric acid solution. The 1:2:2 complex of uranyl(II) ion, nitrate ion and TBAA as extracted species is further confirmed by IR spectra of the extraction of uranyl(II) ion with TBAA. The values of the thermodynamic parameters have also been calculated. (author)

  19. Corrosion mechanism of Z3 CN18.10 stainless steel in the presence of nitric acid condensates

    International Nuclear Information System (INIS)

    Balbaud, Fanny

    1998-01-01

    In installations handling concentrated boiling nitric acid, a severe intergranular corrosion can sometimes occur in condensation zones constituted of non-sensitized Z3 CN 18.10 stainless steel. Corrosion tests in reactors and in a specific loop, CIRCE, allowed to specify the conditions of occurrence of this type of corrosion and showed the similitude with the corrosion in non-renewed liquid nitric acid: the specific parameters linked to the condensate phase are the high ratio metallic surface area to volume of condensate and the low renewing rate which induce a concentration of oxidation products of the metal and of reduction products of nitric acid. The initiation of the intergranular corrosion is attributed to the increase in the reduction rate of nitric acid by an autocatalytic mechanism which was demonstrated by electrochemical measurements on platinum and on stainless steel. The reduction mechanism involves a charge transfer step where nitrous acid, the electro-active species, is reduced into nitrogen monoxide and a chemical regeneration reaction of nitrous acid. The thermodynamic study led to a representation of the chemical and electrochemical properties of nitric acid. This study allowed also to determine the Gibbs free energy of formation of nitrous acid in solution in concentrated nitric acid at 100 deg. C. The diagram, constructed in coordinates log(P O 2 ) / [-log(P HNO 3 )] or E eXperimental / [-log(P HNO 3 )], shows that the final reduction product of nitric acid depends on the concentration of nitric acid: at 100 deg. C, NO is obtained for concentrations lower than 8 mol.L -1 and NO 2 is obtained for higher concentrations. All these results allowed to propose a corrosion mechanism of Z3 CN 18.10 stainless steel in the presence of nitric acid condensates. [fr

  20. Selective toxicity of a quinoxaline 1,4-di-N-oxide derivative in human tumour cell lines.

    Science.gov (United States)

    Amaia, Azquetaa; Pachón, Gisela; Cascante, Marta; Creppy, Edmond E; Monge, Antonio; López de Cerain, Adela

    2005-01-01

    The presence of hypoxic cells in human solid tumours is one of the causes of tumour resistance to conventional therapy, and is also associated with processes that promote the tumour progression. Different chemical agents have been designed in order to take advantage of the particular metabolic characteristics of hypoxic regions. These drugs, called bioreductive agents, are activated inside the hypoxic cells to give active species that, in the presence of oxygen, are oxidised back to the non-toxic parent compound. Several quinoxaline 1,4-di-N-oxides have been described as potential bioreductive agents, and among them, 7-cloro-3-[[(N,N-dimethylamino)propy]amino]-2-quinoxalinecarbonitrile 1,4-di-N-oxide hydrocloride (Q-85 HCl) appeared to be the most promising one. In the present work, the selective cytotoxicity of Q-85 HCl was studied in several human tumour cell lines of different origin (Caco2, MCF-7, HT-29 and Tk-10). Cell viability was calculated after 2 h treatment under hypoxic and well-oxygenated conditions. The potency (the concentration that gives 1% of cell survival) in hypoxia and hypoxia cytotoxicity ratio (HCR = potency in oxygenated conditions/potency in hypoxia) were calculated after a 14-day clonogenic assay. Q-85 HCl was more toxic in hypoxia than in well-oxygenated cells in all the tumour cell lines. The best profile of potency in hypoxia (0.4 micromol/L) and selectivity (HCR=155) was found in CaCo-2 cells. Altogether, these results suggest an in vitro biological profile for Q-85 HCl that makes it an interesting candidate for the development as a bioreductive agent.

  1. Nitric Oxide in Mammary Tumor Progression

    Science.gov (United States)

    1998-07-01

    vance. Ann Surg 221: 339-349, 1995 38. Edwards P, Cendan JC, Topping DB, Moldawer LL, Mackay 24. Albina JE: On the expression of nitric oxide synthase...Carcinogen 16: 20-31, 68. Kibbey MC, Grant DS, Kleinman HK: Role of SIKVAV site 1996 of laminin in promotion of angiogenesis and tumor growth: 55. Albina ...therapy on the development and progression of 77. Albina JE, Abate JA, Henry WL Jr.: Nitric oxide production spontaneous mammary tumors in C3H/HCJ mice

  2. Nitrate tolerance impairs nitric oxide-mediated vasodilation in vivo

    DEFF Research Database (Denmark)

    Laursen, Jørn Bech; Boesgaard, Søren; Poulsen, Henrik E.

    1996-01-01

    Nitrates, Nitrate tolerence, Nitric oxide, acetylcholine, N-acetylcholine, N-acetylcysteine, L-NAME, Rat, Anesthetized......Nitrates, Nitrate tolerence, Nitric oxide, acetylcholine, N-acetylcholine, N-acetylcysteine, L-NAME, Rat, Anesthetized...

  3. Implications of glial nitric oxyde in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Jose Enrique eYuste

    2015-08-01

    Full Text Available Nitric oxide (NO is a pleiotropic janus-faced molecule synthesized by nitric oxide synthases (NOS which plays a critical role in a number of physiological and pathological processes in humans. The physiological roles of NO depend on its local concentrations, as well as its availability and the nature of downstream target molecules. Its double-edged sword action has been linked to neurodegenerative disorders. Excessive NO production, as the evoked by inflammatory signals, has been identified as one of the major causative reasons for the pathogenesis of several neurodegenerative diseases. Moreover, excessive NO synthesis under neuroinflammation leads to the formation of reactive nitrogen species and neuronal cell death. There is an intimate relation between microglial activation, NO and neuroinflammation in the human brain. The role of NO in neuroinflammation has been defined in animal models where this neurotransmitter can modulate the inflammatory process acting on key regulatory pathways, such as those associated with excitotoxicity processes induced by glutamate accumulation and microglial activation. Activated glia express inducible NOS and produce NO that triggers calcium mobilization from the endoplasmic reticulum, activating the release of vesicular glutamate from astroglial cells resulting in neuronal death. This change in microglia potentially contributes to the increased age-associated susceptibility and neurodegeneration. In the current review, information is provided about the role of NO, glial activation and age-related processes in the central nervous system (CNS that may be helpful in the isolation of new therapeutic targets for aging and neurodegenerative diseases.

  4. Role of Protein Phosphatase 1 and Inhibitor of Protein Phosphatase-1 in Nitric Oxide-Dependent Inhibition of the DNA Damage Response in Pancreatic β-Cells.

    Science.gov (United States)

    Oleson, Bryndon J; Naatz, Aaron; Proudfoot, Sarah C; Yeo, Chay Teng; Corbett, John A

    2018-02-14

    Nitric oxide is produced at micromolar levels by pancreatic β-cells during exposure to proinflammatory cytokines. While classically viewed as damaging, nitric oxide also activates pathways that promote β-cell survival. We have shown that nitric oxide, in a cell type selective manner, inhibits the DNA damage response (DDR) and, in doing so, protects β-cells from DNA damage-induced apoptosis. This study explores potential mechanisms by which nitric oxide inhibits DDR signaling. We show that inhibition of DDR signaling (measured by γH2AX formation and the phosphorylation of KAP1) is selective for nitric oxide, as other forms of reactive oxygen/nitrogen species do not impair DDR signaling. The kinetics and broad range of DDR substrates that are inhibited suggest that protein phosphatase activation may be one mechanism by which nitric oxide attenuates DDR signaling in β-cells. While protein phosphatase 1 (PP1) is a primary regulator of DDR signaling and an inhibitor of protein phosphatase-1 (IPP-1) is selectively expressed only in β-cells, disruption of either IPP-1 or PP1 does not modify the inhibitory actions of nitric oxide on DDR signaling in β-cells. These findings support a PP1-independent mechanism by which nitric oxide selectively impairs DDR signaling and protects β-cells from DNA damage-induced apoptosis. © 2018 by the American Diabetes Association.

  5. Containment of Nitric Acid Solutions of Plutonium-238

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Silver, G.L.; Pansoy-Hjelvik, L.; Ramsey, K.

    1999-01-01

    The corrosion of various metals that could be used to contain nitric acid solutions of Pu-238 has been studied. Tantalum and tantalum/2.5% tungsten resisted the test solvent better than 304L stainless steel and several INCONEL alloys. The solvent used to imitate nitric acid solutions of Pu-238 contained 70% nitric acid, hydrofluoric acid, and ammonium hexanitratocerate

  6. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)

    Endothelial nitric oxide synthase (NOS3) is involved in key steps of immune response. Genetic factors predispose individuals to periodontal disease. This study's aim was to explore the association between NOS3 gene polymorphisms and clinical parameters in patients with periodontal disease. Genomic DNA was obtained ...

  7. Targeting nitric oxide in the gastrointestinal tract

    NARCIS (Netherlands)

    Dijkstra, Gerard; van Goor, Harm; Jansen, Peter L M; Moshage, Han

    This review discusses the contributions of the three nitric oxide (NO) synthase (NOS) isozymes neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS) to the function and diseases of the gastrointestinal tract. Small (nanomolar) quantities of NO produced by calcium-dependent nNOS play a

  8. Targeting nitric oxide in the gastrointestinal tract

    NARCIS (Netherlands)

    Dijkstra, Gerard; van Goor, Harry; Jansen, Peter L. M.; Moshage, Han

    2004-01-01

    This review discusses the contributions of the three nitric oxide (NO) synthase (NOS) isozymes neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS) to the function and diseases of the gastrointestinal tract. Small (nanomolar) quantities of NO produced by calcium-dependent nNOS play a

  9. ORIGINAL ARTICLE Relationship between endothelial nitric oxide ...

    African Journals Online (AJOL)

    salah

    and limits the oxidation of low-density lipoproteins, all these mechanisms be- ing strongly involved in the atherogenic process5. Moreover, as a potent vasodi- latator, NO is deeply engaged in the regulation of blood pressure. In vascular endothelium, NO is con- stitutively produced from L-arginine by endothelial nitric oxide ...

  10. Reduced arginine availability and nitric oxide production

    NARCIS (Netherlands)

    Hallemeesch, M. M.; Lamers, W. H.; Deutz, N. E. P.

    2002-01-01

    The precursor for nitric oxide (NO) synthesis is the amino acid arginine. Reduced arginine availability may limit NO production. Arginine availability for NO synthesis may be regulated by de novo arginine production from citrulline, arginine transport across the cell membrane, and arginine breakdown

  11. Nitric oxide flow tagging in unseeded air

    NARCIS (Netherlands)

    Dam, N; Klein-Douwel, RJH; Sijtsema, NM; ter Meulen, JJ

    2001-01-01

    A scheme for molecular tagging velocimetry is presented that can be used in air flows without any kind of seeding. The method is based on the local and instantaneous creation of nitric oxide (NO) molecules from Nz and O-2 in the waist region of a focused ArF excimer laser beam. This NO distribution

  12. Nitric oxide enhances osmoregulation of tobacco ( Nicotiana ...

    African Journals Online (AJOL)

    This study was carried out to investigate the effect of the intracellular signaling molecule nitric oxide (NO) on osmoregulation of tobacco cells under osmotic stress caused by phenylethanoid glycosides 6000 (PEG 6000). The results show that the PEG stress induced a specific pattern of endogenous NO production with two ...

  13. Indirect evaluation of corneal apoptosis in contact lens wearers by estimation of nitric oxide and antioxidant enzymes in tears

    Directory of Open Access Journals (Sweden)

    R P Bhatia

    2010-01-01

    Full Text Available Background : Contact lens induced trauma to the corneal epithelium results in increased release of inflammatory mediators. The keratocyte apoptosis is directly related to epithelial injury and has been correlated with increased production of nitric oxide. Potent antioxidant enzymes protect cells from oxidative damage by inactivating reactive oxygen species and thus inhibiting apoptosis. This study aims at determination of total nitric oxide and antioxidant enzymes in tears which will be an indirect criteria for assessing apoptosis. Materials and Methods : Nitric oxide and antioxidant enzymes were estimated in tears of 25 soft contact lens wearers and compared with 25 age and sex matched controls. Results : Statistically significant increase of nitric oxide (P< 0.001, superoxide dismutase (P< 0.001 and glutathione peroxidase (P< 0.001 levels was seen in tears of contact lens wearers as compared to controls. There was also statistically significant increase in the levels of antioxidant enzymes, superoxide dismutase (P< 0.05 and glutathione peroxidase (P< 0.01, with increase in the total duration of contact lens wear in years. Conclusions : Increase in the level of nitric oxide and antioxidant enzymes in tears of contact lens wearers suggested that contact lens wear suppresses the process of apoptosis. However, it was also postulated that the increased levels of nitric oxide balances the anti-apoptotic activities of increased levels of antioxidant enzymes by its pro-apoptotic activity leading to protective outcomes in contact lens wearers.

  14. Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

    Directory of Open Access Journals (Sweden)

    Bruno P. Carreira

    2015-01-01

    Full Text Available Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO. In these conditions, NO promotes proliferation of neural stem cells (NSC in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA induced seizure mouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.

  15. Isotope tracing enhancement of chemiluminescence assays for nitric oxide research.

    Science.gov (United States)

    Cornelius, Julia; Tran, Tuan; Turner, Nicole; Piazza, Abigail; Mills, Lauren; Slack, Ryan; Hauser, Sean; Alexander, J Steven; Grisham, Matthew B; Feelisch, Martin; Rodriguez, Juan

    2009-02-01

    Chemiluminescence assays are used widely for the detection of nitric oxide (NO)-derived species in biological fluids and tissues. Here, we demonstrate that these assays can be interfaced with mass-sensitive detectors for parallel determination of isotopic abundance. Results obtained with tri-iodide and ascorbic acid-based reductive assays indicate that mass spectrometric detection enables NO isotope-tracing experiments to be carried out to a limit of detectability of a few picomoles, a sensitivity similar to that of standard gas phase chemiluminescence methods. The advantage afforded by mass spectrometric detection is demonstrated using the murine macrophage cell line J774, which is shown here to reduce 15NO3- to 15NO2- under anoxic conditions. The particular combination of an analytical and cellular system described here may hold promise for future characterization of the enzymatic pathways contributing to mammalian nitrate reductase activity, without background interference from 14NO2- derived from other sources.

  16. Nitric oxide in the rat cerebellum after hypoxia/ischemia.

    Science.gov (United States)

    Rodrigo, José; Fernández, Ana Patricia; Alonso, David; Serrano, Julia; Fernández-Vizarra, Paula; Martínez-Murillo, Ricardo; Bentura, María Luisa; Martinez, Alfredo

    2004-01-01

    Nitric oxide is a regulatory biological substance and an important intracellular messenger that acts as a specific mediator of various neuropathological disorders. In mammals and invertebrates, nitric oxide is synthesized from L-arginine in the central and peripheral neural structures by the endothelial, neuronal and inducible enzymatic isoforms of nitric oxide synthase. Nitric oxide may affect the function of various neurotransmitter-specific systems, and is involved in neuromodulation, reproductive function, immune response, and regulation of the cerebral blood circulation. This makes nitric oxide the main candidate in brain responses to brain ischemia/hypoxia. The cerebellum has been reported to be the area of the brain that has the highest nitric oxide synthase activity and the highest concentration of glutamate and aspartate. By glutamate receptors and physiological action of nitric oxide, cyclic guanisine-5'-monophosphate may be rapidly increased. The cerebellum significantly differs with respect to ischemia and hypoxia, this response being directly related to the duration and intensity of the injury. The cerebellum could cover the eventual need for nitric oxide during the hypoxia, boosting the nitric oxide synthase activity, but overall ischemia would require de novo protein synthesis, activating the inducible nitric oxide synthase to cope with the new situation. The specific inhibitors of nitric oxide synthesis show neuroprotective effects.

  17. Defense gene induction in tobacco by nitric oxide, cyclic GMP, and cyclic ADP-ribose

    OpenAIRE

    Durner, Jörg; Wendehenne, David; Klessig, Daniel F.

    1998-01-01

    Reactive oxygen species are believed to perform multiple roles during plant defense responses to microbial attack, acting in the initial defense and possibly as cellular signaling molecules. In animals, nitric oxide (NO) is an important redox-active signaling molecule. Here we show that infection of resistant, but not susceptible, tobacco with tobacco mosaic virus resulted in enhanced NO synthase (NOS) activity. Furthermore, administration of NO donors or recombinant mammalian NOS to tobacco ...

  18. Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas

    OpenAIRE

    Liu, Yong-Biao; Yang, Xiangbing; Masuda, Tiffany

    2017-01-01

    Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on fresh products and procedures for residue analysis and product quality evaluation. An airtight fumigation chamber containing fresh fruit and vegetables is first flushed with nitrogen (N2) to establish an ultralow oxygen (ULO) environment followed by injection of NO. The fumigation chamber is then kept at a low temperature of 2 - 5 °C for a speci...

  19. Two state reactivity mechanism for the rearrangement of hydrogen peroxynitrite to nitric acid

    Science.gov (United States)

    Contreras, Renato; Galván, Marcelo; Oliva, Mónica; Safont, Vincent S.; Andrés, Juan; Guerra, Doris; Aizman, Arie

    2008-05-01

    For the isomerization of HOONO to nitric acid, a spin triplet reactive intermediate 3HOONO ∗ was identified on a two state reactivity (TSR) potential energy surface. This bi-radical is postulated as one of the possible activated species responsible for the potent oxidant activity attributed to H-peroxynitrite. A theoretical analysis based on spin density-dependent reactivity indices consistently explains the observed reactivity of this molecule in biological and model systems.

  20. Therapeutic strategies to address neuronal nitric oxide synthase deficiency and the loss of nitric oxide bioavailability in Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Timpani, Cara A; Hayes, Alan; Rybalka, Emma

    2017-05-25

    Duchenne Muscular Dystrophy is a rare and fatal neuromuscular disease in which the absence of dystrophin from the muscle membrane induces a secondary loss of neuronal nitric oxide synthase and the muscles capacity for endogenous nitric oxide synthesis. Since nitric oxide is a potent regulator of skeletal muscle metabolism, mass, function and regeneration, the loss of nitric oxide bioavailability is likely a key contributor to the chronic pathological wasting evident in Duchenne Muscular Dystrophy. As such, various therapeutic interventions to re-establish either the neuronal nitric oxide synthase protein deficit or the consequential loss of nitric oxide synthesis and bioavailability have been investigated in both animal models of Duchenne Muscular Dystrophy and in human clinical trials. Notably, the efficacy of these interventions are varied and not always translatable from animal model to human patients, highlighting a complex interplay of factors which determine the downstream modulatory effects of nitric oxide. We review these studies herein.

  1. Removal of fluoride from aqueous nitric acid

    International Nuclear Information System (INIS)

    Pruett, D.J.; Howerton, W.B.; Mailen, J.C.

    1981-06-01

    Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca 2+ -Al 3+ ) chemical trap-distillation system. Zirconium oxynitrate solutions were found to be superior in preventing volatilization of fluoride during distillation of the nitric acid, producing decontamination factors (DFs) on the order of 2 x 10 3 (vs approx. 500 for the Ca 2+ -Al 3+ system). Several other metal nitrate systems were tested, but they were less effective. Alumina and zirconia columns proved highly effective in removing HF from HF-HNO 3 vapors distilled through the columns; fluoride DFs on the order of 10 6 and 10 4 , respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO 3 solutions, producing a fluoride DF of approx. 10 4

  2. Metastable Nitric Acid Trihydrate in Ice Clouds.

    Science.gov (United States)

    Weiss, Fabian; Kubel, Frank; Gálvez, Óscar; Hoelzel, Markus; Parker, Stewart F; Baloh, Philipp; Iannarelli, Riccardo; Rossi, Michel J; Grothe, Hinrich

    2016-03-01

    The composition of high-altitude ice clouds is still a matter of intense discussion. The constituents in question are ice and nitric acid hydrates, but the exact phase composition of clouds and its formation mechanisms are still unknown. In this work, conclusive evidence for a long-predicted phase, alpha-nitric acid trihydrate (alpha-NAT), is presented. This phase was characterized by a combination of X-ray and neutron diffraction experiments, allowing a convincing structure solution. Furthermore, vibrational spectra (infrared and inelastic neutron scattering) were recorded and compared with theoretical calculations. A strong interaction between water ice and alpha-NAT was found, which explains the experimental spectra and the phase-transition kinetics. On the basis of these results, we propose a new three-step mechanism for NAT formation in high-altitude ice clouds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Oxygen, nitric oxide and articular cartilage

    Directory of Open Access Journals (Sweden)

    B Fermor

    2007-04-01

    Full Text Available Molecular oxygen is required for the production of nitric oxide (NO, a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O2, while the deep zone exists at less than 1% O2. Furthermore, oxygen tension can alter matrix synthesis, and the material properties of articular cartilage in vitro.The increase in nitric oxide associated with arthritis can be caused by pro-inflammatory cytokines and mechanical stress. Oxygen tension significantly alters endogenous NO production in articular cartilage, as well as the stimulation of NO in response to both mechanical loading and pro-inflammatory cytokines. Mechanical loading and pro-inflammatory cytokines also increase the production of prostaglandin E2 (PGE2. There is a complex interaction between NO and PGE2, and oxygen tension can alter this interaction. These findings suggest that the relatively low levels of oxygen within the joint may have significant influences on the metabolic activity, and inflammatory response of cartilage as compared to ambient levels. A better understanding of the role of oxygen in the production of inflammatory mediators in response to mechanical loading, or pro-inflammatory cytokines, may aid in the development of strategies for therapeutic intervention in arthritis.

  4. Cannula sensor for nitric oxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Glazier, S.A. [National Institute of Standard and Technology, Gaithersburg, MD (United States)

    1995-12-31

    Nitric oxide (NO) has received much attention because of its numerous roles in mammalian systems. It has been found in the brain and nervous system to act as a neurotransmitter, in blood vessels as a blood pressure regulator, in the immune system to act as a bactericide and tumorcide, and in other postulated roles as well. Nitric oxide is produced in mammalian cells by the enzyme nitric oxide synthetase. Once produced, NO is oxidized or reacts rapidly with components in living systems and hence has a short half-life. Only a few sensors have been constructed which can detect NO at nanomolar to micromolar levels found in these systems. We are currently examining the use of a cannula sensor employing oxyhemoglobin for NO detection. This sensor continuously draws in liquid sample at a low rate and immediately reacts it with oxyhemoglobin. The absorbance changes which accompany the reaction are monitored. The sensor has a linear response range from approximately 50 to 1000 nM of NO in aqueous solution. Its utility in monitoring NO produced by stimulated murine macrophage cells (RAW 264.7) in culture is currently being examined. The sensor design is generic in that it can also employ fluorescence and chemiluminescence detection chemistries which may allow lower detection limits to be achieved. Details of the sensor`s performance will be given.

  5. Neuroprotective properties of nitric oxide and S-nitrosoglutathione

    International Nuclear Information System (INIS)

    Rauhala, Pekka; Andoh, Tsugunobu; Chiueh, C.C.

    2005-01-01

    Oxidative stress and apoptosis may play an important role in the neurodegeneration. The present paper outlines antioxidative and antiapototic mechanisms of nitric oxide and S-nitrosothiols, which could mediate neuroprotection. Nitric oxide generated by nitric oxide synthase or released from an endogenous S-nitrosothiol, S-nitrosoglutathione may up-regulate antioxidative thioredoxin system and antiapototic Bcl-2 protein through a cGMP-dependent mechanism. Moreover, nitric oxide radicals have been shown to have direct antioxidant effect through their reaction with free radicals and iron-oxygen complexes. In addition to serving as a stabilizer and carrier of nitric oxide, S-nitrosoglutathione may have protective effect through transnitrosylation reactions. Based on these new findings, a hypothesis arises that the homeostasis of nitric oxide, S-nitrosothiols, glutathione, and thioredoxin systems is important for protection against oxidative stress, apoptosis, and related neurodegenerative disorders

  6. Decoding nitric oxide release rates of amine-based diazeniumdiolates.

    Science.gov (United States)

    Wang, Yan-Ni; Collins, Jack; Holland, Ryan J; Keefer, Larry K; Ivanic, Joseph

    2013-08-01

    Amine-based diazeniumdiolates (NONOates) have garnered widespread use as nitric oxide (NO) donors, and their potential for nitroxyl (HNO) release has more recently been realized. While NO release rates can vary significantly with the type of amine, half-lives of seconds to days under physiological conditions, there is as yet no way to determine a priori the NO or HNO production rates of a given species, and no discernible trends have manifested other than that secondary amines produce only NO (i.e., no HNO). As a step to understanding these complex systems, here we describe a procedure for modeling amine-based NONOates in water solvent that provides an excellent correlation (R(2) = 0.94) between experimentally measured dissociation rates of seven secondary amine species and their computed NO release activation energies. The significant difference in behavior of NONOates in the gas and solvent phases is also rigorously demonstrated via explicit additions of quantum mechanical water molecules. The presented results suggest that the as-yet unsynthesized simplest amine-based NONOate, the diazeniumdiolated ammonia anion [H2N-N(O)═NO(-)], could serve as an unperturbed HNO donor. These results provide a step forward toward the accurate modeling of general NO and/or HNO donors as well as for the identification of tailored prodrug candidates.

  7. Salivary contribution to exhaled nitric oxide.

    Science.gov (United States)

    Zetterquist, W; Pedroletti, C; Lundberg, J O; Alving, K

    1999-02-01

    Dietary and metabolic nitrate is distributed from the blood to the saliva by active uptake in the salivary glands, and is reduced to nitrite in the oral cavity by the action of certain bacteria. Since it has been reported that nitric oxide may be formed nonenzymatically from nitrite this study aimed to determine whether salivary nitrite could influence measurements of exhaled NO. Ten healthy subjects fasted overnight and ingested 400 mg potassium nitrate, equivalent to approximately 200 g spinach. Exhaled NO and nasal NO were regularly measured with a chemiluminescence technique up to 3 h after the ingestion. Measurements of exhaled NO were performed with a single-breath procedure, standardized to a 20-s exhalation, at a flow of 0.15 L x s(-1), and oral pressure of 8-10 cmH2O. Values of NO were registered as NO release rate (pmol x s(-1)) during the plateau of exhalation. Exhaled NO increased steadily over time after nitrate load and a maximum was seen at 120 min (77.0+/-15.2 versus 31.2+/-3.0 pmol x s(-1), pnitrite concentrations increased in parallel; at 120 min there was a four-fold increase compared with baseline (1.56+/-0.44 versus 0.37+/-0.09 mM, pnitrite-reducing conditions in the oral cavity were also manipulated by the use of different mouthwash procedures. The antibacterial agent chlorhexidine acetate (0.2%) decreased NO release by almost 50% (pnitrate loading and reduced the preload control levels by close to 30% (pnitric oxide formation contributes to nitric oxide in exhaled air and a large intake of nitrate-rich foods before the investigation might be misinterpreted as an elevated inflammatory activity in the airways. This potential source of error and the means for avoiding it should be considered in the development of a future standardized method for measurements of exhaled nitric oxide.

  8. Hypoxia tolerance, nitric oxide, and nitrite

    DEFF Research Database (Denmark)

    Fago, Angela; Jensen, Frank Bo

    2015-01-01

    survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and – in air breathing animals - redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite...... nitrite. The aim of this review is to highlight recent work illustrating the widespread roles of NO and nitrite in the tolerance to extreme oxygen deprivation, in particular in the red-eared slider turtle and crucian carp, but also in diving marine mammals. The emerging picture underscores the importance...

  9. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    Directory of Open Access Journals (Sweden)

    Nevzat Selim Gokay

    2016-01-01

    Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  10. EFFECTS OF NITRIC ACID ON CRITICALITY SAFETY ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, B.

    2011-08-18

    As nitric acid molarity is increased, there are two competing phenomena affecting the reactivity of the system. First, there is interaction between each of the 10 wells in the basket-like insert. As the molarity of the nitric acid solution is increased (it moves from 100% water to 100% HNO{sub 3}), the hydrogen atom density decreases by about 80%. However, it remains a relatively efficient moderator. The moderating ratio of nitric acid is about 90% that of water. As the media between the wells is changed from 100% water to 100% nitric acid, the density of the media increases by 50%. A higher density typically leads to a better reflector. However, when the macroscopic scattering cross sections are considered, nitric acid is a much worse reflector than water. The effectiveness of nitric acid as a reflector is about 40% that of water. Since the media between the wells become a worse reflector and still remains an effective moderator, interaction between the wells increases. This phenomenon will cause reactivity to increase as nitric acid molarity increases. The seond phenomenon is due to the moderating ratio changing in the high concentration fissile-nitric acid solution in the 10 wells. Since the wells contain relatively small volumes of high concentration solutions, a small decrease in moderating power has a large effect on reactivity. This is due to the fact that neutrons are more likely to escape the high concentration fissile solution before causing another fission event. The result of this phenomenon is that as nitric acid molarity increases, reactivity decreases. Recent studies have shown that the second phenomenon is indeed the dominating force in determining reactivity changes in relation to nitric acid molarity changes. When considering the system as a whole, as nitric acid molarity increases, reactivity decreases.

  11. Inhaled nitric oxide improves systemic microcirculation in infants with hypoxemic respiratory failure

    NARCIS (Netherlands)

    Top, Anke P. C.; Ince, Can; Schouwenberg, Patrick H. M.; Tibboel, Dick

    2011-01-01

    To investigate the effect of inhaled nitric oxide on the systemic microcirculation. We hypothesized that inhaled nitric oxide improves the systemic microcirculation. Inhaled nitric oxide improves outcome in infants with persistent pulmonary hypertension of the newborn diagnosed by improving

  12. Catalytic abatement of nitrous oxide from nitric and production

    NARCIS (Netherlands)

    Oonk, J.

    1998-01-01

    Nitric acid production is identified as a main source of nitrous oxide. Options for emission reduction however are not available. TNO and Hydro Agri studied the technological and economic feasibility of catalytic decomposition of nitrous oxide in nitric acid tail-gases. Although in literature

  13. Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 ...

    African Journals Online (AJOL)

    Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 and Lipid Peroxidation by Methanol Extract of Pericarpium Zanthoxyli. ... Production of iNOS induced by LPS was significantly (p < 0.05) inhibited by the extract, suggesting that the extract inhibits nitric oxide (NO) production by suppressing iNOS expression.

  14. Effect of nitric oxide scavengers, carboxy-PTIO on endotoxin ...

    African Journals Online (AJOL)

    Physiological changes associated with septic shock are due to an interplay of a number of inflammatory mediators which increase capillary permeability and vasodilation leading to circulatory disturbance. Research evidence shows that sepsis-associated vascular relaxation is mediated by nitric oxide. Nitric oxide formation ...

  15. Effect of nitric oxide scavengers, carboxy-PTIO on endotoxin ...

    African Journals Online (AJOL)

    values of the cardiovascular parameters considered in this study. This indicates that carboxy-PTIO is an efficient nitric oxide scavenger chemical of trapping nitric oxide immediately after its synthesis. Therefore, based on the current result, carboxy-PTIO can be used as one possible treatment agent against septic shock.

  16. Adrenoceptor-activated nitric oxide synthesis in salivary acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia; Dissing, Steen; Tritsaris, Katerina

    2000-01-01

    We investigated the cellular regulation of nitric oxide synthase (NOS) activity in isolated acinar cells from rat parotid and human labial salivary glands, using the newly developed fluorescent nitric oxide (NO) indicator, DAF-2. We found that sympathetic stimulation with norepinephrine (NE) caused...

  17. Influence of nitric oxide on histamine and carbachol – induced ...

    African Journals Online (AJOL)

    The study aimed to determine the influence of nitric oxide (NO) on the action of histamine and carbachol on acid secretion in the common African toad – Bufo regularis. Gastric acidity was determined by titration method. The acid secretion was determined when nitric oxide was absent following administration of NO synthase ...

  18. Propolis Ameliorates Tumor Nerosis Factor-α, Nitric Oxide levels ...

    African Journals Online (AJOL)

    Background: Increased nitric oxide (NO), neuronal inflammation and apoptosis have been proposed to be involved in excitotoxicity plays a part in many neurodegenerative diseases. To understand the neuro-protective effects of propolis, activities of Nitric oxide synthase (NOS) and caspase-3 along with NO and tumor ...

  19. Tropospheric Multiphase Chemistry Modeling : Sensitivity Tests Concerning The Sulfate and Nitric Acid Production In The Condensed Phases

    Science.gov (United States)

    Deguillaume, L.; Leriche, M.; Chaumerliac, N.

    Tropospheric multiphase chemistry is still poorly understood, because the interactions between trace gases and the condensed phase are quit complex (Jacob, 2000). A multi- phase chemical box model have been developed with an explicit chemistry for both gas and aqueous phase in Leriche et al. (2000) and in Leriche et al. (2001), the multiphase box model has been coupled with quasi-spectral microphysics, based upon Berry and ReinhardtSs parameterisations (1974 a, b). In these studies, chemical multiphase pro- cesses occurring during one cloudy event observed during the European Cloud Ice Mountain Experiment (CIME) held in 1997 has been investigated . The comparison of the partitioning of chemical species among the gas and condensed phases of the cloud, from model results and from measurements, displays, when collision/coalescence pro- cesses are considered, an improvement in retrieving the partitioning of soluble species, especially for nitric acid. The partitioning of nitric acid depends on the total chemical production of nitric acid both in gas and condensed phases, which is more important when microphysical processes are taken into account due to an important production in rainwater, which is comparable to the production in cloud water. The nitric acid production is related to two precursors in aqueous phase: the pernitric acid and the sulfite ion. Pernitric acid, due to its equilibrium in gas phase and its high solubility, is always available both in cloud water and in rainwater via the mass transfer from gas phase. The sulfite ion comes from the mass transfer from gas phase of the sulfur dioxide in cloud water before rain formation. When rainwater appears, it is efficiently transferred in rainwater by collision/coalescence processes. This two facts lead to an enhancement in nitric acid production when microphysics is considered which leads to a best retrieval of measured nitric acid partitioning. In this review, sensitivity tests are presented. The effect of

  20. Nitric Oxide Metabolites and Asymmetric Dimethylarginine Concentrations in Breast Milk

    Directory of Open Access Journals (Sweden)

    Hakan Öztürk

    2017-04-01

    Full Text Available Objective: Nitric oxide plays a preventive role in the development of necrotizing enterocolitis. Oral nitrite and nitrate intake has gained importance with the discovery of the conversion of nitrite to nitric oxide in acidic medium out of the synthesis of nitric oxide from L-arginine. Objective of this study was to examine the breast milk concentrations of nitric oxide and asymmetric dimethylarginine which is a competitive inhibitor of nitric oxide and to compare these concentrations in terms of gestational age and maturity of breast milk. Study Design: Forty-one women were included in the study. Milk samples were collected from 3 groups of mothers as term, late preterm and preterm on the postpartum days 3, 7 and 28. Results: When breast milk concentrations of nitric oxide were compared according to the postnatal day of the milk independently from gestational age; nitric oxide concentration was higher in the colostrum than in the transition milk and mature milk (p=0,035; p=0,001; respectively. For the comparison of asymmetric dimethylarginine concentrations among these groups and days; no statistically significant difference was observed in terms of gestational age and maturity of the milk (p=0.865, p=0.115; respectively. Conclusion: The highest nitric oxide concentration was found in the colostrum, suggesting that colostrum is a valuable food for newborns. Plasma concentrations of asymmetric dimethylarginine were negatively correlated with nitric oxide and did not show a correlation with breast milk, suggesting that asymmetric dimethylargininedoesn’t make nitric oxide inhibition in breast milk.

  1. Inducible and neuronal nitric oxide synthases exert contrasting effects during rat intestinal recovery following fasting.

    Science.gov (United States)

    Ito, Junta; Uchida, Hiroyuki; Machida, Naomi; Ohtake, Kazuo; Saito, Yuki; Kobayashi, Jun

    2017-04-01

    We investigated the effects of endogenous inducible (iNOS) and neuronal nitric oxide synthase on recovery from intestinal mucosal atrophy caused by fasting-induced apoptosis and decreased cell proliferation during refeeding in rats. Rats were divided into five groups, one of which was fed ad libitum, and four of which underwent 72 h of fasting, followed by refeeding for 0, 6, 24, and 48 h, respectively. iNOS and neuronal nitric oxide synthase mRNA and protein levels in jejunal tissues were measured, and mucosal height was histologically evaluated. Apoptotic indices, interferon-γ (IFN-γ) transcription levels, nitrite levels (as a measure of nitric oxide [NO] production),8-hydroxydeoxyguanosine formation (indicating reactive oxygen species [ROS] levels), crypt cell proliferation, and the motility indices (MI) were also estimated. Associations between mucosal height and NOS protein levels were determined using Spearman's rank correlation test. Notably, we observed significant increases in mucosal height and in neuronal nitric oxide synthase mRNA and protein expression as refeeding time increased. Indeed, there was a significant positive correlation between neuronal nitric oxide synthase protein level and mucosal height during the 48-h refeeding period ( r = 0.725, P fasting. Our finding suggests that refeeding likely repairs fasting-induced jejunal atrophy by suppressing iNOS expression and subsequently inhibiting NO, ROS, and IFN-γ as apoptosis mediators, and by promoting neuronal nitric oxide synthase production and inducing crypt cell proliferation via mechanical stimulation. Impact statement Besides providing new data confirming the involvement of iNOS and nNOS in intestinal mucosal atrophy caused by fasting, this study details their expression and function during recovery from this condition following refeeding. We demonstrate a significant negative correlation between iNOS and nNOS levels during refeeding, and associate this with cell proliferation

  2. Quantitative phosphoproteomics analysis of nitric oxide-responsive phosphoproteins in cotton leaf.

    Directory of Open Access Journals (Sweden)

    Shuli Fan

    Full Text Available Knowledge of phosphorylation events and their regulation is crucial to understanding the functional biology of plant proteins, but very little is currently known about nitric oxide-responsive phosphorylation in plants. Here, we report the first large-scale, quantitative phosphoproteome analysis of cotton (Gossypium hirsutum treated with sodium nitroprusside (nitric oxide donor by utilizing the isobaric tag for relative and absolute quantitation (iTRAQ method. A total of 1315 unique phosphopeptides, spanning 1528 non-redundant phosphorylation sites, were detected from 1020 cotton phosphoproteins. Among them, 183 phosphopeptides corresponding to 167 phosphoproteins were found to be differentially phosphorylated in response to sodium nitroprusside. Several of the phosphorylation sites that we identified, including RQxS, DSxE, TxxxxSP and SPxT, have not, to our knowledge, been reported to be protein kinase sites in other species. The phosphoproteins identified are involved in a wide range of cellular processes, including signal transduction, RNA metabolism, intracellular transport and so on. This study reveals unique features of the cotton phosphoproteome and provides new insight into the biochemical pathways that are regulated by nitric oxide.

  3. Thermal And Spectroscopic Analyses Of Next Generation Caustic Side Solvent Extraction Solvent Contacted With 3, 8, And 16 Molar Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. F.; Fink, S. D.

    2011-12-07

    A new solvent system referred to as Next Generation Solvent or NGS, has been developed at Oak Ridge National Laboratory for the removal of cesium from alkaline solutions in the Caustic Side Solvent Extraction process. The NGS is proposed for deployment at MCU{sup a} and at the Salt Waste Processing Facility. This work investigated the chemical compatibility between NGS and 16 M, 8 M, and 3 M nitric acid from contact that may occur in handling of analytical samples from MCU or, for 3 M acid, which may occur during contactor cleaning operations at MCU. This work shows that reactions occurred between NGS components and the high molarity nitric acid. Reaction rates are much faster in 8 M and 16 M nitric acid than in 3 M nitric acid. In the case of 16 M and 8 M nitric acid, the nitric acid reacts with the extractant to produce initially organo-nitrate species. The reaction also releases soluble fluorinated alcohols such as tetrafluoropropanol. With longer contact time, the modifier reacts to produce a tarry substance with evolved gases (NO{sub x} and possibly CO). Calorimetric analysis of the reaction product mixtures revealed that the organo-nitrates reaction products are not explosive and will not deflagrate.

  4. Reduction of nitric oxide by carbon monoxide over a silica supported platinum catalyst infrared and kinetic studies

    Energy Technology Data Exchange (ETDEWEB)

    Lorimer, D' Arcy Harold [Univ. of California, Berkeley, CA (United States)

    1978-07-01

    The reduction of nitric oxide by carbon monoxide over a 4.5 weight precent platinum catalyst supported on silica was studied at 300 C. Reaction rate data was obtained together with in situ infrared spectra of species on the catalyst surface. The kinetics of the system were found to exhibit two distinct trends, depending on the molar ratio of CO/NO in the reactor. For net reducing conditions (CO/NO> 1) the catalyst underwent a transient deactivation, the extent of which was dependent on the specific CO/NO ratio during reaction. Reactivation of the catalyst was obtained with both oxidizing and reducing pretreatments. For molar feed ratios of CO/NO less than one, carbon monoxide conversion was typically 95 to 100%, resulting in strongly oxidizing conditions over the catalyst. Under these conditions no deactivation was apparent. Infrared spectra recorded under reaction conditions revealed intense bands at 2075 and 2300 cm-1 , which were identified as carbon monoxide adsorbed on Pt and Si-NCO, respectively. Isocyanate bands formed under reducing conditions were more intense and exhibited greater stability than those formed under oxidizing conditions. A reaction mechanism based on the dissociation of nitric oxide as the rate-limiting step was used to correlate nitric oxide reaction rates and nitrous oxide selectivities observed under reducing conditions. As part of this mechanism it is assumed that nitrous bxide is formed via a Langmuir-Hinshelwood process in which an adsorbed nitrogen atom reacts with an adsorbed nitric oxide molecule. The nitric oxide reaction rate was found to be first order in nitric oxide partial pressure, and inverse second order in carbon monoxide partial pressure. A mechanism is proposed to qualitatively explain the deactivation process observed under reducing conditions. The essential part of this mechanism is the formation of an isocyanate species on the Pt crystallites of the catalyst and the subsequent transient diffusion of these

  5. Inhaled nitric oxide augments nitric oxide transport on sickle cell hemoglobin without affecting oxygen affinity

    OpenAIRE

    Gladwin, Mark T.; Schechter, Alan N.; Shelhamer, James H.; Pannell, Lewis K.; Conway, Deirdre A.; Hrinczenko, Borys W.; Nichols, James S.; Pease-Fye, Margaret E.; Noguchi, Constance T.; Rodgers, Griffin P.; Ognibene, Frederick P.

    1999-01-01

    Nitric oxide (NO) inhalation has been reported to increase the oxygen affinity of sickle cell erythrocytes. Also, proposed allosteric mechanisms for hemoglobin, based on S-nitrosation of β-chain cysteine 93, raise the possibilty of altering the pathophysiology of sickle cell disease by inhibiting polymerization or by increasing NO delivery to the tissue. We studied the effects of a 2-hour treatment, using varying concentrations of inhaled NO. Oxygen affinity, as measured by P50, did not respo...

  6. Physiology of nitric oxide in the respiratory system.

    Science.gov (United States)

    Antosova, M; Mokra, D; Pepucha, L; Plevkova, J; Buday, T; Sterusky, M; Bencova, A

    2017-09-22

    Nitric oxide (NO) is an important endogenous neurotransmitter and mediator. It participates in regulation of physiological processes in different organ systems including airways. Therefore, it is important to clarify its role in the regulation of both airway and vascular smooth muscle, neurotransmission and neurotoxicity, mucus transport, lung development and in the. surfactant production. The bioactivity of NO is highly variable and depends on many factors: the presence and activity of NO-producing enzymes, activity of competitive enzymes (e.g. arginase), the amount of substrate for the NO production, the presence of reactive oxygen species and others. All of these can change NO primary physiological role into potentially harmful. The borderline between them is very fragile and in many cases not entirely clear. For this reason, the research focuses on a comprehensive understanding of NO synthesis and its metabolic pathways, genetic polymorphisms of NO synthesizing enzymes and related effects. Research is also motivated by frequent use of exhaled NO monitoring in the clinical manifestations of respiratory diseases. The review focuses on the latest knowledge about the production and function of this mediator and understanding the basic physiological processes in the airways.

  7. Genetic biosensors for imaging nitric oxide in single cells.

    Science.gov (United States)

    Eroglu, Emrah; Charoensin, Suphachai; Bischof, Helmut; Ramadani, Jeta; Gottschalk, Benjamin; Depaoli, Maria R; Waldeck-Weiermair, Markus; Graier, Wolfgang F; Malli, Roland

    2018-02-01

    Over the last decades a broad collection of sophisticated fluorescent protein-based probes was engineered with the aim to specifically monitor nitric oxide (NO), one of the most important signaling molecules in biology. Here we report and discuss the characteristics and fields of applications of currently available genetically encoded fluorescent sensors for the detection of NO and its metabolites in different cell types. Because of its radical nature and short half-life, real-time imaging of NO on the level of single cells is challenging. Herein we review state-of-the-art genetically encoded fluorescent sensors for NO and its byproducts such as peroxynitrite, nitrite and nitrate. Such probes enable the real-time visualization of NO signals directly or indirectly on the level of single cells and cellular organelles and, hence, extend our understanding of the spatiotemporal dynamics of NO formation, diffusion and degradation. Here, we discuss the significance of NO detection in individual cells and on subcellular level with genetic biosensors. Currently available genetically encoded fluorescent probes for NO and nitrogen species are critically discussed in order to provide insights in the functionality and applicability of these promising tools. As an outlook we provide ideas for novel approaches for the design and application of improved NO probes and fluorescence imaging protocols. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Toluene nitration in irradiated nitric acid and nitrite solutions

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Gracy, E-mail: gracy.elias@inl.go [Idaho National Laboratory, Chemical and Radiation Measurement Department, P.O. Box 1625, Idaho Falls, ID 83415-2213 (United States); Mincher, Bruce J. [Idaho National Laboratory, Aqueous Separations and Radiochemistry Department, P.O. Box 1625, Idaho Falls, ID 83415-6180 (United States); Mezyk, Stephen P. [California State University-Long Beach, Department of Chemistry and Biochemistry, 1250 Bellflower Boulevard, Long Beach, CA 90840-3903 (United States); Muller, Jim [University of Utah, Department of Chemistry, Salt Lake City, UT 84112-0850 (United States); Martin, Leigh R. [Idaho National Laboratory, Aqueous Separations and Radiochemistry Department, P.O. Box 1625, Idaho Falls, ID 83415-6180 (United States)

    2011-04-15

    The kinetics, mechanisms, and stable products produced for the nitration of aryl alkyl mild ortho-para director toluene in irradiated nitric acid and neutral nitrite solutions were investigated using {gamma} and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection, GC-MS and LC-MS, were used to assess the stable reaction products. Free-radical based nitration reaction products were found in irradiated acidic and neutral media. In 6.0 M HNO{sub 3}, ring substitution, side chain substitution, and oxidation, produced different nitrated toluene products. For ring substitution, nitrogen oxide radicals were added mainly to cyclohexadienyl radicals, whereas for side chain substitution, these radicals were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite solutions, radiolytically-induced ring nitration products approached a statistically random distribution, suggesting a direct free-radical reaction involving addition of the {sup {center_dot}N}O{sub 2} radical.

  9. Toluene nitration in irradiated nitric acid and nitrite solutions

    Science.gov (United States)

    Elias, Gracy; Mincher, Bruce J.; Mezyk, Stephen P.; Muller, Jim; Martin, Leigh R.

    2011-04-01

    The kinetics, mechanisms, and stable products produced for the nitration of aryl alkyl mild ortho-para director toluene in irradiated nitric acid and neutral nitrite solutions were investigated using γ and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection, GC-MS and LC-MS, were used to assess the stable reaction products. Free-radical based nitration reaction products were found in irradiated acidic and neutral media. In 6.0 M HNO3, ring substitution, side chain substitution, and oxidation, produced different nitrated toluene products. For ring substitution, nitrogen oxide radicals were added mainly to cyclohexadienyl radicals, whereas for side chain substitution, these radicals were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite solutions, radiolytically-induced ring nitration products approached a statistically random distribution, suggesting a direct free-radical reaction involving addition of the rad NO2 radical.

  10. Toluene nitration in irradiated nitric acid and nitrite solution

    Energy Technology Data Exchange (ETDEWEB)

    Gracy Elias; Bruce J. Mincher; Stephen P. Mezyk; Jim Muller; Leigh R. Martin

    2011-04-01

    The kinetics, mechanisms, and stable products produced for the aryl alkyl mild ortho-para director - toluene, in irradiated nitric acid and neutral nitrite solutions were investigated using ?, and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection was primarily used to assess the stable reaction products. GC-MS and LC-MS were used to confirm the results from HPLC. Free-radical nitration reaction products were found in irradiated acidic and neutral media. In acidic medium, the ring substitution and side chain substitution and oxidation produced different nitro products. In ring substitution, nitrogen oxide radicals were added mainly to hydroxyl radical-produced cyclohexadienyl radical, and in side chain substitution they were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite toluene solution, radiolytic ring nitration products approached a statistically random distribution, suggesting a free-radical reaction involving addition of the •NO2 radical.

  11. Toluene nitration in irradiated nitric acid and nitrite solutions

    International Nuclear Information System (INIS)

    Elias, Gracy; Mincher, Bruce J.; Mezyk, Stephen P.; Muller, Jim; Martin, Leigh R.

    2011-01-01

    The kinetics, mechanisms, and stable products produced for the nitration of aryl alkyl mild ortho-para director toluene in irradiated nitric acid and neutral nitrite solutions were investigated using γ and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection, GC-MS and LC-MS, were used to assess the stable reaction products. Free-radical based nitration reaction products were found in irradiated acidic and neutral media. In 6.0 M HNO 3 , ring substitution, side chain substitution, and oxidation, produced different nitrated toluene products. For ring substitution, nitrogen oxide radicals were added mainly to cyclohexadienyl radicals, whereas for side chain substitution, these radicals were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite solutions, radiolytically-induced ring nitration products approached a statistically random distribution, suggesting a direct free-radical reaction involving addition of the · NO 2 radical.

  12. Nitric Oxide: A Multitasked Signaling Gas in Plants

    KAUST Repository

    Domingos, Patricia

    2014-12-01

    Nitric oxide (NO) is a gaseous reactive oxygen species (ROS) that has evolved as a signaling hormone in many physiological processes in animals. In plants it has been demonstrated to be a crucial regulator of development, acting as a signaling molecule present at each step of the plant life cycle. NO has also been implicated as a signal in biotic and abiotic responses of plants to the environment. Remarkably, despite this plethora of effects and functional relationships, the fundamental knowledge of NO production, sensing, and transduction in plants remains largely unknown or inadequately characterized. In this review we cover the current understanding of NO production, perception, and action in different physiological scenarios. We especially address the issues of enzymatic and chemical generation of NO in plants, NO sensing and downstream signaling, namely the putative cGMP and Ca2+ pathways, ion-channel activity modulation, gene expression regulation, and the interface with other ROS, which can have a profound effect on both NO accumulation and function. We also focus on the importance of NO in cell–cell communication during developmental processes and sexual reproduction, namely in pollen tube guidance and embryo sac fertilization, pathogen defense, and responses to abiotic stress.

  13. Citric Acid Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  14. Nitric oxide and mitochondria in metabolic syndrome

    Science.gov (United States)

    Litvinova, Larisa; Atochin, Dmitriy N.; Fattakhov, Nikolai; Vasilenko, Mariia; Zatolokin, Pavel; Kirienkova, Elena

    2015-01-01

    Metabolic syndrome (MS) is a cluster of metabolic disorders that collectively increase the risk of cardiovascular disease. Nitric oxide (NO) plays a crucial role in the pathogeneses of MS components and is involved in different mitochondrial signaling pathways that control respiration and apoptosis. The present review summarizes the recent information regarding the interrelations of mitochondria and NO in MS. Changes in the activities of different NO synthase isoforms lead to the formation of metabolic disorders and therefore are highlighted here. Reduced endothelial NOS activity and NO bioavailability, as the main factors underlying the endothelial dysfunction that occurs in MS, are discussed in this review in relation to mitochondrial dysfunction. We also focus on potential therapeutic strategies involving NO signaling pathways that can be used to treat patients with metabolic disorders associated with mitochondrial dysfunction. The article may help researchers develop new approaches for the diagnosis, prevention and treatment of MS. PMID:25741283

  15. Nitric Oxide Synthase Inhibitors as Antidepressants

    Directory of Open Access Journals (Sweden)

    Vallo Volke

    2010-01-01

    Full Text Available Affective and anxiety disorders are widely distributed disorders with severe social and economic effects. Evidence is emphatic that effective treatment helps to restore function and quality of life. Due to the action of most modern antidepressant drugs, serotonergic mechanisms have traditionally been suggested to play major roles in the pathophysiology of mood and stress-related disorders. However, a few clinical and several pre-clinical studies, strongly suggest involvement of the nitric oxide (NO signaling pathway in these disorders. Moreover, several of the conventional neurotransmitters, including serotonin, glutamate and GABA, are intimately regulated by NO, and distinct classes of antidepressants have been found to modulate the hippocampal NO level in vivo. The NO system is therefore a potential target for antidepressant and anxiolytic drug action in acute therapy as well as in prophylaxis. This paper reviews the effect of drugs modulating NO synthesis in anxiety and depression.

  16. The role of nitric oxide in melanoma.

    Science.gov (United States)

    Yarlagadda, Keerthi; Hassani, John; Foote, Isaac P; Markowitz, Joseph

    2017-12-01

    Nitric oxide (NO) is a small gaseous signaling molecule that mediates its effects in melanoma through free radical formation and enzymatic processes. Investigations have demonstrated multiple roles for NO in melanoma pathology via immune surveillance, apoptosis, angiogenesis, melanogenesis, and on the melanoma cell itself. In general, elevated levels of NO prognosticate a poor outcome for melanoma patients. However, there are processes where the relative concentration of NO in different environments may also serve to limit melanoma proliferation. This review serves to outline the roles of NO in melanoma development and proliferation. As demonstrated by multiple in vivo murine models and observations from human tissue, NO may promote melanoma formation and proliferation through its interaction via inhibitory immune cells, inhibition of apoptosis, stimulation of pro-tumorigenic cytokines, activation of tumor associated macrophages, alteration of angiogenic processes, and stimulation of melanoma formation itself. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. The role of nitric oxide in stroke

    Directory of Open Access Journals (Sweden)

    Zhou-qing Chen

    2017-01-01

    Full Text Available Stroke is considered to be an acute cerebrovascular disease, including ischemic stroke and hemorrhagic stroke. The high incidence and poor prognosis of stroke suggest that it is a highly disabling and highly lethal disease which can pose a serious threat to human health. Nitric oxide (NO, a common gas in nature, which is often thought as a toxic gas, because of its intimate relationship with the pathological processes of many diseases, especially in the regulation of blood flow and cell inflammation. However, recent years have witnessed an increased interest that NO plays a significant and positive role in stroke as an essential gas signal molecule. In view of the fact that the neuroprotective effect of NO is closely related to its concentration, cell type and time, only in the appropriate circumstances can NO play a protective effect. The purpose of this review is to summarize the roles of NO in ischemic stroke and hemorrhagic stroke.

  18. Nebivolol Ameliorates Nitric Oxide–Deficient Hypertension

    Directory of Open Access Journals (Sweden)

    L.A. Fortepiani

    2002-01-01

    Full Text Available Nebivolol is a new selective beta 1-adrenoceptor antagonist with nitric oxide (NO–releasing properties. In the present study we have analyzed whether nebivolol affects the development of the arterial hypertension that follows the chronic inhibition of nitric oxide synthesis. Nebivolol (1 mg/kg/day, 14 days was given concurrently with the NO synthesis inhibitor Nw-nitro-L-arginine methyl ester (L-NAME, 0.1, 1, and 10 mg/kg/day, 14 days to several groups of rats. Blood pressure, renal function, plasma renin activity (PRA, and NO activity and metabolites were measured at the end of the treatment period. L-NAME treatment alone increased mean arterial pressure dose dependently (103.5 ± 2.4, 110.9 ± 2.0, and 125.8 ± 2.2 mmHg, respectively. Nebivolol completely prevented the development of arterial hypertension in the groups treated with L-NAME at the doses of 0.1 and 1 mg/kg/day and reduced the increase achieved with the L-NAME dose of 10 mg/kg/day (110.3 ± 2.7. There were no differences in glomerular filtration rate or natriuresis between nebivolol-treated and -untreated rats. Plasma nitrates+nitrites and calcium-dependent NO synthase activity in the kidney also decreased dose dependently with L-NAME treatment and nebivolol did not significantly modify it. However, PRA was lower in all groups treated with nebivolol and L-NAME as compared to the rats receiving only L-NAME. These data indicate that nebivolol prevents the development of the arterial hypertension associated with chronic NO deficit and this effect seems to be dependent on the inhibition of renin-angiotensin system.

  19. Interaction and reactivity of nitric oxide and carbon monoxide on ruthenium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Quick, E.E.

    1980-03-01

    A multifaceted investigation of the reduction of nitric oxide by carbon monoxide using a ruthenium (102) single crystal catalyst in the pressure range 10/sup -3/ to 10 Torr and temperature range of 300 to 475/sup 0/C has been undertaken. Kinetic and isotopic results indicate that the reaction products CO/sub 2/ and N/sub 2/ were produced via two reaction mechanisms. Using a reducing gas mixture (low P/sub NO//P/sub CO/ ratio) a two site mechanism was operative involving NO dissociation. The carbon monoxide kinetic order varied from +1 to -3 and the nitric oxide order varied from +1 to 0. The catalyst under these conditions was determined to be metallic ruthenium with oxygen bonded within the first surface layer. The oxygen was unreactive and formed a (1 x 3)-0 LEED pattern. Under oxidizing conditions (high P/sub NO//P/sub CO/ ratio) the catalyst was ruthenium dioxide and the functional mechanism under these reaction conditions yielded a nitric oxide order of +2 to -4. Inclusion of a site poisoning mechanism under reducing conditions and an RuO/sub 2/ growth mechanism involving ruthenium cation transfer under oxidizing conditions into the kinetic rate laws led to an overall rate law which could be fit to the carbon monoxide and nitric oxide order plots. Using isotopically oxygen labelled reactants, it was observed that the three possible isotopes of carbon dioxide were produced. A ..gamma..-CO surface species is postulated as an intermediate in the exchange process. The reaction was observed to be initially surface structure insensitive and the reaction kinetics were derived using a Langmuir-Hinshelwood formalism.

  20. Nitric oxide in the psychobiology of mental disorders

    Directory of Open Access Journals (Sweden)

    Altan Eşsizoğlu

    2009-03-01

    Full Text Available Nitric oxide is in a gaseous form and is widespread in the human body. It functions by acting as a secondary messenger in the modulatory activities of neuronal functions of the central nervous system. Nitric oxide is the first identified neurotransmitter of the nontraditional neurotransmitter family.Studies conducted on experimental animals demonstrate that nitric oxide has a neuromodulatory efficacy on the secretions of other neurotransmitters and that it has an effect on learning and memory functions, and on various neuronal mechanisms. Many studies have been conducted to investigate the location of nitric oxide in the central nervous system, its effect on anxiety and depression, its relationship with other neurotransmitters, and also about its role on neurotoxicity. There are clinical studies concerning the level of nitrate, a product of nitric oxide metabolism, and also experimental studies concerning its rewarding effect of alcohol and substance use, in patients with depression and schizophrenia. However, limited studies have been conducted to investigate its relationship with stress, which is an important factor in the etiology of psychiatric disorders. These studies demonstrate that nitric oxide is closely related with stress physiology.Nitric oxide is a neuromodulator, which is frequently being mentioned about nowadays in psychiatry. Clinical and experimental studies play an important role in the psychobiology of psychiatric disorders.

  1. NO to cancer: The complex and multifaceted role of nitric oxide and the epigenetic nitric oxide donor, RRx-001☆

    Science.gov (United States)

    Scicinski, Jan; Oronsky, Bryan; Ning, Shoucheng; Knox, Susan; Peehl, Donna; Kim, Michelle M.; Langecker, Peter; Fanger, Gary

    2015-01-01

    The endogenous mediator of vasodilation, nitric oxide (NO), has been shown to be a potent radiosensitizer. However, the underlying mode of action for its role as a radiosensitizer – while not entirely understood – is believed to arise from increased tumor blood flow, effects on cellular respiration, on cell signaling, and on the production of reactive oxygen and nitrogen species (RONS), that can act as radiosensitizers in their own right. NO activity is surprisingly long-lived and more potent in comparison to oxygen. Reports of the effects of NO with radiation have often been contradictory leading to confusion about the true radiosensitizing nature of NO. Whether increasing or decreasing tumor blood flow, acting as radiosensitizer or radioprotector, the effects of NO have been controversial. Key to understanding the role of NO as a radiosensitizer is to recognize the importance of biological context. With a very short half-life and potent activity, the local effects of NO need to be carefully considered and understood when using NO as a radiosensitizer. The systemic effects of NO donors can cause extensive side effects, and also affect the local tumor microenvironment, both directly and indirectly. To minimize systemic effects and maximize effects on tumors, agents that deliver NO on demand selectively to tumors using hypoxia as a trigger may be of greater interest as radiosensitizers. Herein we discuss the multiple effects of NO and focus on the clinical molecule RRx-001, a hypoxia-activated NO donor currently being investigated as a radiosensitizer in the clinic. PMID:26164533

  2. Physiological Levels of Nitric Oxide Diminish Mitochondrial Superoxide. Potential Role of Mitochondrial Dinitrosyl Iron Complexes and Nitrosothiols

    Directory of Open Access Journals (Sweden)

    Sergey I. Dikalov

    2017-11-01

    Full Text Available Mitochondria are the major source of superoxide radicals and superoxide overproduction contributes to cardiovascular diseases and metabolic disorders. Endothelial dysfunction and diminished nitric oxide levels are early steps in the development of these pathological conditions. It is known that physiological production of nitric oxide reduces oxidative stress and inflammation, however, the precise mechanism of “antioxidant” effect of nitric oxide is not clear. In this work we tested the hypothesis that physiological levels of nitric oxide diminish mitochondrial superoxide production without inhibition of mitochondrial respiration. In order to test this hypothesis we analyzed effect of low physiological fluxes of nitric oxide (20 nM/min on superoxide and hydrogen peroxide production by ESR spin probes and Amplex Red in isolated rat brain mitochondria. Indeed, low levels of nitric oxide substantially attenuated both basal and antimycin A-stimulated production of reactive oxygen species in the presence of succinate or glutamate/malate as mitochondrial substrates. Furthermore, slow releasing NO donor DPTA-NONOate (100 μM did not change oxygen consumption in State 4 and State 3. However, the NO-donor strongly inhibited oxygen consumption in the presence of uncoupling agent CCCP, which is likely associated with inhibition of the over-reduced complex IV in uncoupled mitochondria. We have examined accumulation of dinitrosyl iron complexes and nitrosothiols in mitochondria treated with fast-releasing NO donor MAHMA NONOate (10 μM for 30 min until complete release of NO. Following treatment with NO donor, mitochondria were frozen for direct detection of dinitrosyl iron complexes using Electron Spin Resonance (ESR while accumulation of nitrosothiols was measured by ferrous-N-Methyl-D-glucamine dithiocarbamate complex, Fe(MGD2, in lysed mitochondria. Treatment of mitochondria with NO-donor gave rise to ESR signal of dinitrosyl iron complexes while ESR

  3. Dissolution behavior of PFBR MOX fuel in nitric acid

    International Nuclear Information System (INIS)

    Kelkar, Anoop; Kapoor, Y.S.; Singh, Mamta; Meena, D.L.; Pandey, Ashish; Bhatt, R.B.; Behere, P.G.

    2017-01-01

    Present paper describes the dissolution characteristics of PFBR MOX fuel (U,Pu)O 2 in nitric acid. An overview of batch dissolution experiments, studying the percentage dissolution of uranium and plutonium in (U, Pu)O 2 MOX sintered pellets with different percentage of PuO 2 with reference to time and nitric acid concentration are described. 90% of uranium and plutonium of PFBR MOX gets dissolves in 2 hrs and amount of residue increases with the decrease in nitric acid concentration. Overall variation in percentage residue in PFBR MOX fuel after dissolution test also described. (author)

  4. Alternative control techniques document: Nitric and adipic acid manufacturing plants

    International Nuclear Information System (INIS)

    Lazzo, D.W.

    1991-12-01

    The Alternative Control Techniques document describes available control techniques for reducing NOx emission levels from nitric and adipic acid manufacturing plants. The document contains information on the formation of NOx and uncontrolled NOx emissions from nitric and adipic acid plants. The following NOx control techniques for nitric acid plants are discussed: extended absorption, nonselective catalytic reduction (NSCR), and selective catalytic reduction (SCR). The following NOx control techniques for adipic acid plants are discussed: extended absorption and thermal reduction. For each control technique, achievable controlled NOx emission levels, capital and annual costs, cost effectiveness, and environmental and energy impacts are presented

  5. Alternative control techniques document: Nitric and adipic acid manufacturing plants

    Energy Technology Data Exchange (ETDEWEB)

    Lazzo, D.W.

    1991-12-01

    The Alternative Control Techniques document describes available control techniques for reducing NOx emission levels from nitric and adipic acid manufacturing plants. The document contains information on the formation of NOx and uncontrolled NOx emissions from nitric and adipic acid plants. The following NOx control techniques for nitric acid plants are discussed: extended absorption, nonselective catalytic reduction (NSCR), and selective catalytic reduction (SCR). The following NOx control techniques for adipic acid plants are discussed: extended absorption and thermal reduction. For each control technique, achievable controlled NOx emission levels, capital and annual costs, cost effectiveness, and environmental and energy impacts are presented.

  6. Leaching of sodium carbonate cakes by nitric acid

    International Nuclear Information System (INIS)

    Troyanker, L.S.; Nikonov, V.N.

    1977-01-01

    The interaction has been studied of soda cakes of fluorite-rare-earth concentrate with nitric acid. The effect of a number of factors on extraction of REE into a nitric solution has been considered: the final acidity of the pulp, the duration of leaching, and the ratio between solid and liquid phases. The effect of adding aluminium nitrate into the pulp has also been studied. It has been shown that three-stage counterflow leaching of soda cakes with nitric acid increases REE extraction approximately by 10%

  7. Two-color laser absorption near 5 μm for temperature and nitric oxide sensing in high-temperature gases

    Science.gov (United States)

    Almodovar, Christopher A.; Spearrin, R. Mitchell; Hanson, Ronald K.

    2017-12-01

    An infrared laser-absorption technique for in situ temperature and nitric oxide species sensing in high-temperature gases is presented. A pair of quantum cascade lasers in the mid-infrared near 5 μm were utilized to probe rovibrational transitions in nitric oxide's fundamental band. The line parameters of the selected transitions, including line strengths and collision broadening coefficients of nitric oxide with argon and nitrogen, were evaluated during controlled room-temperature static cell experiments and high-temperature shock tube experiments at temperatures between 1000 and 3000 K, and pressures between 1 and 5 atm. These studies provided new insights into the temperature dependence of nitric oxide collision broadening, highlighting the inadequacies of the power law over a broad temperature range. With an accurate spectroscopic model over a broad temperature range, the quantitative two-color temperature sensing strategy was demonstrated in non-reactive shock tube experiments from 1000 to 3000 K to validate thermometry and during a nitric oxide formation experiment near 1700 K and 4 atm to highlight capability for temporally-resolved species measurements at MHz rates. The technique has applicability for sensing in a broad range of flow fields that involve high-temperature air.

  8. Arylboronate ester based diazeniumdiolates (BORO/NO), a class of hydrogen peroxide inducible nitric oxide (NO) donors.

    Science.gov (United States)

    Dharmaraja, Allimuthu T; Ravikumar, Govindan; Chakrapani, Harinath

    2014-05-16

    Here, we report the design, synthesis, and evaluation of arylboronate ester based diazeniumdiolates (BORO/NO), a class of nitric oxide (NO) donors activated by hydrogen peroxide (H2O2), a reactive oxygen species (ROS), to generate NO. We provide evidence for the NO donors' ability to permeate bacteria to produce NO when exposed to H2O2 supporting possible applications for BORO/NO to study molecular mechanisms of NO generation in response to elevated ROS.

  9. Nitric oxide production, inhibitory, antioxidant and antimycobacterial activities of the fruits extract and flavonoid content of Schinus terebinthifolius

    Directory of Open Access Journals (Sweden)

    Natalia R. Bernardes

    Full Text Available The extract of the fruits from Schinus terebinthifolius Raddi, Anacardiaceae, was obtained by exhaustive extraction with methanol. Its fractions and isolated compounds were collected by fractionation with RP-2 column chromatography. The crude extract, the flavonoid fraction and the isolated compound identified as apigenin (1, were investigated regarding its inhibitory action of nitric oxide production by LPS-stimulated macrophages, antioxidant activity by DPPH and the antimycobacterial activity against Mycobacterium bovis BCG. The samples exhibited a significant inhibitory effect on the nitric oxide production (e.g., 1, IC50 19.23 ± 1.64 µg/ml and also showed antioxidant activity. In addition, S. terebinthifolius samples inhibited the mycobacterial growth ( e.g., 1, IC50 14.53 ± 1.25 µg/ml. The necessary concentration to produce 50% of the maximum response (IC50 of these activities did not elicit a significant cytotoxic effect when compared with the positive control (100% of lysis. The antioxidant and nitric oxide inhibition activity displayed by S. terebinthifolius corroborates its ethnopharmacological use of this specie as an anti-inflammatory. In addition, our results suggest that the flavonoids of S. terebinthifolius are responsible for the activities found. We, describe for the first time the activity against Mycobacterium bovis BCG and the inhibition of nitric oxide production for S. terebinthifolius.

  10. The Regulation of Nitric Oxide Synthase Isoform Expression in Mouse and Human Fallopian Tubes: Potential Insights for Ectopic Pregnancy

    Directory of Open Access Journals (Sweden)

    Junting Hu

    2014-12-01

    Full Text Available Nitric oxide (NO is highly unstable and has a half-life of seconds in buffer solutions. It is synthesized by NO-synthase (NOS, which has been found to exist in the following three isoforms: neuro nitric oxide synthase (nNOS, inducible nitric oxide synthase (iNOS, and endothelial nitric oxide synthase (eNOS. NOS activity is localized in the reproductive tracts of many species, although direct evidence for NOS isoforms in the Fallopian tubes of mice is still lacking. In the present study, we investigated the expression and regulation of NOS isoforms in the mouse and human Fallopian tubes during the estrous and menstrual cycles, respectively. We also measured isoform expression in humans with ectopic pregnancy and in mice treated with lipopolysaccharide (LPS. Our results confirmed the presence of different NOS isoforms in the mouse and human Fallopian tubes during different stages of the estrous and menstrual cycles and showed that iNOS expression increased in the Fallopian tubes of women with ectopic pregnancy and in LPS-treated mice. Elevated iNOS activity might influence ovulation, cilia beats, contractility, and embryo transportation in such a manner as to increase the risk of ectopic pregnancy. This study has provided morphological and molecular evidence that NOS isoforms are present and active in the human and mouse Fallopian tubes and suggests that iNOS might play an important role in both the reproductive cycle and infection-induced ectopic pregnancies.

  11. Nitric oxide synthase and nitric oxide alterations in chronically stressed rats: a model for nitric oxide in major depressive disorder.

    Science.gov (United States)

    Gao, Shang-Feng; Lu, Yun-Rong; Shi, Li-Gen; Wu, Xue-Yan; Sun, Bo; Fu, Xin-Yan; Luo, Jian-Hong; Bao, Ai-Min

    2014-09-01

    Nitric oxide (NO) and NO synthase-1 (NOS1) are involved in the stress response and in depression. We compared NOS-NO alterations in rats exposed to chronic unpredictable stress (CUS) with alterations in major depressive disorder (MDD) in humans. In the hypothalamus of male CUS rats we determined NOS activity, and in the paraventricular nucleus (PVN) we determined NOS1-immunoreactive (ir) cell densities and co-localization of NOS1 with stress-related neuropeptides corticotropin-releasing hormone (CRH), vasopressin (AVP) or oxytocin (OXT). We measured plasma NO levels and cortisol in male medicine-naïve MDD patients and plasma NO and corticosterone (CORT) in CUS rats. In the CUS rat total NOS activity in the hypothalamus (P=0.018) and NOS1-ir cell density in the PVN were both significantly decreased (P=0.018), while NOS1 staining was mainly expressed in OXT-ir neurons in this nucleus. Interestingly, plasma NO levels were significantly increased both in male CUS rats (P=0.001) and in male MDD patients (Pdepression. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Chemical and spectral behavior of nitric acid in aqueous sulfuric acid solutions: Absorption spectrum and molar absorption coefficient of nitronium ion

    Science.gov (United States)

    Ershov, Boris G.; Panich, Nadezhda M.

    2018-01-01

    The chemical species formed from nitric acid in aqueous solutions of sulfuric acid (up to 18.0 mol L- 1) were studied by optical spectroscopy method. The concentration region of nitronium ion formation was identified and NO2+ ion absorption spectrum was measured (λmax ≤ 190 nm and ε190 = 1040 ± 50 mol- 1 L cm- 1).

  13. Nitric oxide inhibits glycogen synthesis in isolated rat hepatocytes

    NARCIS (Netherlands)

    Sprangers, F.; Sauerwein, H. P.; Romijn, J. A.; van Woerkom, G. M.; Meijer, A. J.

    1998-01-01

    There is increasing evidence for the existence of intrahepatic regulation of glucose metabolism by Kupffer cell products. Nitric oxide (NO) is known to inhibit gluconeogenic flux through pyruvate carboxylase and phosphoenolpyruvate carboxykinase. However, NO may also influence glucose metabolism at

  14. Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of ...

    African Journals Online (AJOL)

    Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of Nuclear Factor-κB Activation in Interleukin-1β- Stimulated SW1353 Chondrosarcoma Cells. P Jia, G Chen, R Li, X Rong, G Zhou, Y Zhong ...

  15. Acute Respiratory Distress Syndrome (ARDS After Nitric Acid Inhalation

    Directory of Open Access Journals (Sweden)

    Gülay Kır

    2014-12-01

    Full Text Available Lung injury resulting from inhalation of chemical products continues to be associated with high morbidity and mortality. Concentrated nitric acids are also extremely corrosive fuming chemical liquids. Fumes of nitric acid (HNO3 and various oxides of nitrogen such as nitric oxide (NO and nitrogen dioxide (NO2 may cause fatal illnesses such as severe pulmonary edema and acute respiratory distress syndrome (ARDS when inhaled. Intensive respiratory management including mechanical ventilation with positive end expiratory pressure (PEEP, inverse ratio ventilation, replacement of surfactant and extracorporeal membrane oxygenation (ECMO, steroids and n-acetylcysteine (NAC may improve survival. In this case report we present the diagnosis and successful treatment of a 57 years old male patient who developed ARDS following pulmonary edema due to nitric acid fumes inhalation.

  16. Studies on the reaction of nitric acid and sugar

    International Nuclear Information System (INIS)

    MacDougall, C.S.; Bayne, C.K.; Roberson, R.B.

    1982-01-01

    The design of vessels and off-gas systems for denitrating acidic radioactive process solutions by reacting nitric acid with sugar requires a fairly accurate determination of the rate of the controlling step. Therefore, the reaction of sugar with concentrated nitric acid was closely examined at temperatures of 100 and 110 0 C and in the presence of low levels of iron )0 to 0.2 M Fe(III)). Efficiencies of the sugar destruction by nitric acid ranged from 2.56 to 2.93 mol of acid consumed per mole of carbon added. Product off-gases were examined throughout the reaction. Release of CO was fairly constant throughout the reaction, but amounts of CO 2 increased as the nitric acid began to attack the terminal carboxylic acids produced from the consumption of sucrose. Voluminous quantities of NO 2 were released at the beginning of the reaction, but larger relative concentrations of NO were observed toward the end

  17. Update on the Use of Inhaled Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Robert M Kacmarek

    1996-01-01

    Full Text Available A literature review on nitric oxide would identify thousands of citations on the biological implications of this molecule. From the perspective of respiratory care, the effect inhaled nitric oxide has on pulmonary vasculature is the most intriguing. Over the past five years inhaled nitric oxide has been shown to be useful in the management of oxygenation during acute respiratory distress syndrome, alternation of pulmonary vascular tone in persistent pulmonary hypertension in the newborn, and in the management of chronic pulmonary hypertension in both heart and lung transplant candidates, as well as other potential clinical uses. The key physioligical response is vasodilation of pulmonary vessels in communication with well ventilated lung units and the absence of systemic vascular effects by rapid binding to hemoglobin. Nitric oxide therapy is considered experimental. A delivery system is not commercially available. This has resulted in the development of makeshift delivery systems, many of which may have the potential for adverse effects.

  18. Adhesion Development and the Expression of Endothelial Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    David M. Svinarich

    2001-01-01

    Full Text Available Objective: This study was conducted to determine whether nitric oxide (NO, a potent vasodilator and inhibitor of thrombus formation, is involved in the formation and maintenance of adhesions.

  19. Acute chemical pneumonitis caused by nitric acid inhalation: case report

    International Nuclear Information System (INIS)

    Choe, Hyung Shim; Lee, In Jae; Ko, Eun Young; Lee, Jae Young; Kim, Hyun Beom; Hwang, Dae Hyun; Lee, Kwan Seop; Lee, Yul; Bae, Sang Hoon

    2003-01-01

    Chemical pneumonitis induced by nitric acid inhalation is a rare clinical condition. The previously reported radiologic findings of this disease include acute permeability pulmonary edema, delayed bronchiolitis obliterans, and bronchiectasis. In very few published rare radiologic reports has this disease manifested as acute alveolar injury; we report a case of acute chemical pneumonitis induced by nitric acid inhalation which at radiography manifested as bilateral perihilar consolidation and ground-glass attenuation, suggesting acute alveolar injury

  20. NITRIC OXIDE INTERFERES WITH HYPOXIA SIGNALING DURING COLONIC INFLAMMATION

    OpenAIRE

    CARIA,Cintia Rabelo e Paiva; MOSCATO,Camila Henrique; TOMÉ,Renata Bortolin Guerra; PEDRAZZOLI Jr,José; RIBEIRO,Marcelo Lima; GAMBERO,Alessandra

    2014-01-01

    Context Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs). Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. Objectives We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. Methods Colitis was induced by single (acute) or repeated (reactivated colitis) trinitrobenzenosulfonic acid administ...

  1. Formation of nitric acid hydrates - A chemical equilibrium approach

    Science.gov (United States)

    Smith, Roland H.

    1990-01-01

    Published data are used to calculate equilibrium constants for reactions of the formation of nitric acid hydrates over the temperature range 190 to 205 K. Standard enthalpies of formation and standard entropies are calculated for the tri- and mono-hydrates. These are shown to be in reasonable agreement with earlier calorimetric measurements. The formation of nitric acid trihydrate in the polar stratosphere is discussed in terms of these equilibrium constants.

  2. Acute chemical pneumonitis caused by nitric acid inhalation: case report

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Hyung Shim; Lee, In Jae; Ko, Eun Young; Lee, Jae Young; Kim, Hyun Beom; Hwang, Dae Hyun; Lee, Kwan Seop; Lee, Yul; Bae, Sang Hoon [Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of)

    2003-06-01

    Chemical pneumonitis induced by nitric acid inhalation is a rare clinical condition. The previously reported radiologic findings of this disease include acute permeability pulmonary edema, delayed bronchiolitis obliterans, and bronchiectasis. In very few published rare radiologic reports has this disease manifested as acute alveolar injury; we report a case of acute chemical pneumonitis induced by nitric acid inhalation which at radiography manifested as bilateral perihilar consolidation and ground-glass attenuation, suggesting acute alveolar injury.

  3. Nitric acid recycling and copper nitrate recovery from effluent.

    Science.gov (United States)

    Jô, L F; Marcus, R; Marcelin, O

    2014-01-01

    The recycling of nitric acid and copper nitrate contained in an industrial effluent was studied. The experiments conducted on such a medium showed that the presence of copper nitrate significantly improves nitric acid-water separation during distillation in an azeotropic medium. At the temperature of the azeotrope, however, this metal salt starts to precipitate, making the medium pasty, thus inhibiting the nitric acid extraction process. The optimisation of parameters such as column efficiency and adding water to the boiler at the azeotrope temperature are recommended in this protocol in order to collect the various components while avoiding the formation of by-products: NOx compounds. Thus, the absence of column, along with the addition of a small volume of water at a temperature of 118 °C, significantly increases the yield, allowing 94 % nitric acid to be recovered at the end of the process, along with the residual copper nitrate. The resulting distillate, however, is sufficiently dilute to not be used as is. Rectification is required to obtain concentrated nitric acid at 15 mol·l(-1), along with a weakly acidic distillate from the distillation front. This latter is quenched using potassium hydroxide and is used as a fertiliser solution for horticulture or sheltered market gardening. This process thus allows complete recycling of all the medium's components, including that of the distillate resulting from the nitric acid rectification operation.

  4. Nitric oxide synthase in ferret brain: localization and characterization.

    Science.gov (United States)

    Matsumoto, T.; Mitchell, J. A.; Schmidt, H. H.; Kohlhaas, K. L.; Warner, T. D.; Förstermann, U.; Murad, F.

    1992-01-01

    1. In the present study, we have investigated the distribution of nitric oxide synthase in the ferret brain. Nitric oxide synthase was determined biochemically and immunochemically. 2. In the rat brain, the highest nitric oxide synthase activity has been detected in the cerebellum. However, in the ferret brain, the highest activity was found in the striatum and the lowest in the cerebellum and cerebral cortex. The enzymatic activity was localized predominantly in the cytosolic fractions, it was dependent on NADPH and Ca2+, and inhibited by NG-nitro-L-arginine or NG-methyl-L-arginine. 3. Western blot analysis revealed that all regions of the ferret brain contained a 160 kD protein crossreacting with an antibody to nitric oxide synthase purified from the rat cerebellum, and the levels of relative intensity of staining by the antibody correlated with the distribution of nitric oxide synthase activity. 4. These results indicate that the ferret brain contains a nitric oxide synthase similar to the rat brain, but the distribution of enzymatic activity in the ferret brain differs markedly from the rat brain. Images Figure 1 PMID:1282076

  5. Nitric oxide negatively regulates mammalian adult neurogenesis

    Science.gov (United States)

    Packer, Michael A.; Stasiv, Yuri; Benraiss, Abdellatif; Chmielnicki, Eva; Grinberg, Alexander; Westphal, Heiner; Goldman, Steven A.; Enikolopov, Grigori

    2003-08-01

    Neural progenitor cells are widespread throughout the adult central nervous system but only give rise to neurons in specific loci. Negative regulators of neurogenesis have therefore been postulated, but none have yet been identified as subserving a significant role in the adult brain. Here we report that nitric oxide (NO) acts as an important negative regulator of cell proliferation in the adult mammalian brain. We used two independent approaches to examine the function of NO in adult neurogenesis. In a pharmacological approach, we suppressed NO production in the rat brain by intraventricular infusion of an NO synthase inhibitor. In a genetic approach, we generated a null mutant neuronal NO synthase knockout mouse line by targeting the exon encoding active center of the enzyme. In both models, the number of new cells generated in neurogenic areas of the adult brain, the olfactory subependyma and the dentate gyrus, was strongly augmented, which indicates that division of neural stem cells in the adult brain is controlled by NO and suggests a strategy for enhancing neurogenesis in the adult central nervous system.

  6. Nitric oxide bioavailability dysfunction involves in atherosclerosis.

    Science.gov (United States)

    Chen, Jing-Yi; Ye, Zi-Xin; Wang, Xiu-Fen; Chang, Jian; Yang, Mei-Wen; Zhong, Hua-Hua; Hong, Fen-Fang; Yang, Shu-Long

    2018-01-01

    The pathological characteristics of atherosclerosis (AS) include lipid accumulation, fibrosis formation and atherosclerotic plaque produced in artery intima, which leads to vascular sclerosis, lumen stenosis and irritates the ischemic changes of corresponding organs. Endothelial dysfunction was closely associated with AS. Nitric oxide (NO) is a multifunctional signaling molecule involved in the maintenance of metabolic and cardiovascular homeostasis. NO is also a potent endogenous vasodilator and enters for the key processes that suppresses the formation vascular lesion even AS. NO bioavailability indicates the production and utilization of endothelial NO in organisms, its decrease is related to oxidative stress, lipid infiltration, the expressions of some inflammatory factors and the alteration of vascular tone, which plays an important role in endothelial dysfunction. The enhancement of arginase activity and the increase in asymmetric dimethylarginine and hyperhomocysteinemia levels all contribute to AS by intervening NO bioavailability in human beings. Diabetes mellitus, obesity, chronic kidney disease and smoking, etc., also participate in AS by influencing NO bioavailability and NO level. Here, we reviewed the relationship between NO bioavailability and AS according the newest literatures. Copyright © 2017. Published by Elsevier Masson SAS.

  7. The oral microbiome and nitric oxide homoeostasis.

    Science.gov (United States)

    Hezel, M P; Weitzberg, E

    2015-01-01

    The tiny radical nitric oxide (NO) participates in a vast number of physiological functions including vasodilation, nerve transmission, host defence and cellular energetics. Classically produced by a family of specific enzymes, NO synthases (NOSs), NO signals via reactions with other radicals or transition metals. An alternative pathway for the generation of NO is the nitrate-nitrite-NO pathway in which the inorganic anions nitrate (NO(3)(-)) and nitrite (NO(2)(-)) are reduced to NO and other reactive nitrogen intermediates. Nitrate and nitrite are oxidation products from NOS-dependent NO generation but also constituents in our diet, mainly in leafy green vegetables. Irrespective of origin, active uptake of circulating nitrate in the salivary glands, excretion in saliva and subsequent reduction to nitrite by oral commensal bacteria are all necessary steps for further NO generation. This central role of the oral cavity in regulating NO generation from nitrate presents a new and intriguing aspect of the human microbiome in health and disease. In this review, we present recent advances in our understanding of the nitrate-nitrite-NO pathway and specifically highlight the importance of the oral cavity as a hub for its function. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Nitric oxide and cardiovascular risk factors

    Directory of Open Access Journals (Sweden)

    Livio Dai Cas

    2007-06-01

    Full Text Available The endothelium is a dynamic organ with many properties that takes part in the regulation of the principal mechanisms of vascular physiology. Its principal functions include the control of blood-tissue exchange and permeability, the vascular tonus, and the modulation of inflammatory or coagulatory mechanisms. Many vasoactive molecules, produced by the endothelium, are involved in the control of these functions. The most important is nitric oxide (NO, a gaseous molecule electrically neutral with an odd number of electrons that gives the molecule chemically reactive radical properties. Already known in the twentieth century, NO, sometimes considered as a dangerous molecule, recently valued as an important endogenous vasodilator factor. Recently, it was discovered that it is involved in several physiological mechanisms of endothelial protection (Tab. I. In 1992, Science elected it as “molecule of the year”; 6 yrs later three American researchers (Louis Ignarro, Robert Furchgott and Fried Murad obtained a Nobel Prize for Medicine and Physiology “for their discoveries about NO as signal in the cardiovascular system”.

  9. Arsenic triggers the nitric oxide (NO) and S-nitrosoglutathione (GSNO) metabolism in Arabidopsis

    International Nuclear Information System (INIS)

    Leterrier, Marina; Airaki, Morad; Palma, José M.; Chaki, Mounira; Barroso, Juan B.; Corpas, Francisco J.

    2012-01-01

    Environmental contamination by arsenic constitutes a problem in many countries, and its accumulation in food crops may pose health complications for humans. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are involved at various levels in the mechanism of responding to environmental stress in higher plants. Using Arabidopsis seedlings exposed to different arsenate concentrations, physiological and biochemical parameters were analyzed to determine the status of ROS and RNS metabolisms. Arsenate provoked a significant reduction in growth parameters and an increase in lipid oxidation. These changes were accompanied by an alteration in antioxidative enzymes and the nitric oxide (NO) metabolism, with a significant increase in NO content, S-nitrosoglutathione reductase (GSNOR) activity and protein tyrosine nitration as well as a concomitant reduction in glutathione and S-nitrosoglutathione (GSNO) content. Our results indicate that 500 μM arsenate (AsV) causes nitro-oxidative stress in Arabidopsis, being the glutathione reductase and the GSNOR activities clearly affected. - Highlights: ► In Arabidopsis, arsenate provokes damages in the membrane integrity of root cells. ► As induces an oxidative stress according to an increase in lipid oxidation. ► NO content and protein tyrosine nitration increases under arsenate stress. ► Arsenate provokes a reduction of GSH, GSSG and GSNO content. ► Arsenate induces a nitro-oxidative stress in Arabidopsis. - Arsenic stress affects nitric oxide (NO) and glutathione (GSH) metabolism which provokes a nitro-oxidative stress.

  10. Nitric oxide signaling in the development and evolution of language and cognitive circuits.

    Science.gov (United States)

    Funk, Owen H; Kwan, Kenneth Y

    2014-09-01

    The neocortex underlies not only remarkable motor and sensory capabilities, but also some of our most distinctly human cognitive functions. The emergence of these higher functions during evolution was accompanied by structural changes in the neocortex, including the acquisition of areal specializations such as Broca's speech and language area. The study of these evolutionary mechanisms, which likely involve species-dependent gene expression and function, represents a substantial challenge. These species differences, however, may represent valuable opportunities to understand the molecular underpinnings of neocortical evolution. Here, we discuss nitric oxide signaling as a candidate mechanism in the assembly of neocortical circuits underlying language and higher cognitive functions. This hypothesis was based on the highly specific mid-fetal pattern of nitric oxide synthase 1 (NOS1, previously nNOS) expression in the pyramidal (projection) neurons of two human neocortical areas respectively involved in speech and language, and higher cognition; the frontal operculum (FOp) and the anterior cingulate cortex (ACC). This expression is transiently present during mid-gestation, suggesting that NOS1 may be involved in the development of these areas and the assembly of their neural circuits. As no other gene product is known to exhibit such exquisite spatiotemporal expression, NOS1 represents a remarkable candidate for these functions. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  11. Starved Escherichia coli preserve reducing power under nitric oxide stress

    Energy Technology Data Exchange (ETDEWEB)

    Gowers, Glen-Oliver F. [Department of Molecular Biology, Princeton University, Princeton, NJ (United States); Robinson, Jonathan L. [Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ (United States); Brynildsen, Mark P., E-mail: mbrynild@princeton.edu [Department of Molecular Biology, Princeton University, Princeton, NJ (United States); Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ (United States)

    2016-07-15

    Nitric oxide (NO) detoxification enzymes, such as NO dioxygenase (NOD) and NO reductase (NOR), are important to the virulence of numerous bacteria. Pathogens use these defense systems to ward off immune-generated NO, and they do so in environments that contain additional stressors, such as reactive oxygen species, nutrient deprivation, and acid stress. NOD and NOR both use reducing equivalents to metabolically deactivate NO, which suggests that nutrient deprivation could negatively impact their functionality. To explore the relationship between NO detoxification and nutrient deprivation, we examined the ability of Escherichia coli to detoxify NO under different levels of carbon source availability in aerobic cultures. We observed failure of NO detoxification under both carbon source limitation and starvation, and those failures could have arisen from inabilities to synthesize Hmp (NOD of E. coli) and/or supply it with sufficient NADH (preferred electron donor). We found that when limited quantities of carbon source were provided, NO detoxification failed due to insufficient NADH, whereas starvation prevented Hmp synthesis, which enabled cells to maintain their NADH levels. This maintenance of NADH levels under starvation was confirmed to be dependent on the absence of Hmp. Intriguingly, these data show that under NO stress, carbon-starved E. coli are better positioned with regard to reducing power to cope with other stresses than cells that had consumed an exhaustible amount of carbon. -- Highlights: •Carbon source availability is critical to aerobic E. coli NO detoxification. •Carbon source starvation, under NO stress, preserves intracellular NADH levels. •Preservation of NADH depends on starvation-dependent inhibition of Hmp induction.

  12. An X-ray photoelectron spectroscopic study of a nitric acid/argon ion cleaned uranium metal surface at elevated temperature

    International Nuclear Information System (INIS)

    Paul, A.J.; Sherwood, P.M.A.

    1987-01-01

    X-ray photoelectron spectroscopy has been used to study the surface of uranium metal cleaned by nitric acid treatment and argon ion etching, followed by heating in a high vacuum. The surface is shown to contain UOsub(2-x) species over the entire temperature range studied. Heating to temperatures in the range 400-600 0 C generates a mixture of this oxide, the metal and a carbide and/or oxycarbide species. (author)

  13. Genetic responses against nitric oxide toxicity

    Directory of Open Access Journals (Sweden)

    B. Demple

    1999-11-01

    Full Text Available The threat of free radical damage is opposed by coordinated responses that modulate expression of sets of gene products. In mammalian cells, 12 proteins are induced by exposure to nitric oxide (NO levels that are sub-toxic but exceed the level needed to activate guanylate cyclase. Heme oxygenase 1 (HO-1 synthesis increases substantially, due to a 30- to 70-fold increase in the level of HO-1 mRNA. HO-1 induction is cGMP-independent and occurs mainly through increased mRNA stability, which therefore indicates a new NO-signaling pathway. HO-1 induction contributes to dramatically increased NO resistance and, together with the other inducible functions, constitutes an adaptive resistance pathway that also defends against oxidants such as H2O2. In E. coli, an oxidative stress response, the soxRS regulon, is activated by direct exposure of E. coli to NO, or by NO generated in murine macrophages after phagocytosis of the bacteria. This response is governed by the SoxR protein, a homodimeric transcription factor (17-kDa subunits containing [2Fe-2S] clusters essential for its activity. SoxR responds to superoxide stress through one-electron oxidation of the iron-sulfur centers, but such oxidation is not observed in reactions of NO with SoxR. Instead, NO nitrosylates the iron-sulfur centers of SoxR both in vitro and in intact cells, which yields a form of the protein with maximal transcriptional activity. Although nitrosylated SoxR is very stable in purified form, the spectroscopic signals for the nitrosylated iron-sulfur centers disappear rapidly in vivo, indicating an active process to reverse or eliminate them.

  14. NO to cancer: The complex and multifaceted role of nitric oxide and the epigenetic nitric oxide donor, RRx-001.

    Science.gov (United States)

    Scicinski, Jan; Oronsky, Bryan; Ning, Shoucheng; Knox, Susan; Peehl, Donna; Kim, Michelle M; Langecker, Peter; Fanger, Gary

    2015-12-01

    The endogenous mediator of vasodilation, nitric oxide (NO), has been shown to be a potent radiosensitizer. However, the underlying mode of action for its role as a radiosensitizer - while not entirely understood - is believed to arise from increased tumor blood flow, effects on cellular respiration, on cell signaling, and on the production of reactive oxygen and nitrogen species (RONS), that can act as radiosensitizers in their own right. NO activity is surprisingly long-lived and more potent in comparison to oxygen. Reports of the effects of NO with radiation have often been contradictory leading to confusion about the true radiosensitizing nature of NO. Whether increasing or decreasing tumor blood flow, acting as radiosensitizer or radioprotector, the effects of NO have been controversial. Key to understanding the role of NO as a radiosensitizer is to recognize the importance of biological context. With a very short half-life and potent activity, the local effects of NO need to be carefully considered and understood when using NO as a radiosensitizer. The systemic effects of NO donors can cause extensive side effects, and also affect the local tumor microenvironment, both directly and indirectly. To minimize systemic effects and maximize effects on tumors, agents that deliver NO on demand selectively to tumors using hypoxia as a trigger may be of greater interest as radiosensitizers. Herein we discuss the multiple effects of NO and focus on the clinical molecule RRx-001, a hypoxia-activated NO donor currently being investigated as a radiosensitizer in the clinic. Copyright © 2015. Published by Elsevier B.V.

  15. Regulation and Turnover of Nitric Oxide by Phytoglobins in Plant Cell Responses

    DEFF Research Database (Denmark)

    Igamberdiev, Abir U; Hebelstrup, Kim; Stasolla, Claudio

    2016-01-01

    The involvement of phytoglobins in the metabolism of nitric oxide (NO) and reactive nitrogen species (RNS) produced during stress, plant growth, and development is discussed. The action of phytoglobin expression upon NO leads to the maintenance of redox status, minimization of the damage from...... reactive oxygen and nitrogen species in the cytoplasm of the cell, and regulation of hormonal and stress responses. NO scavenging is achieved via phytoglobins, and it can also involve S-nitrosoglutathione reductase and a direct interaction of NO with superoxide anion followed by detoxification of formed...... to the mobility of both NO and phytohormones, plants developed strategies to regulate specific cell hormonal actions to permit differentiation during development and to respond to stress. Phytoglobins are the agents responsible for differential cellular responses to hormones that use NO as a signal transduction...

  16. Mitochondrial dysfunction associated with nitric oxide pathways in glutamate neurotoxicity.

    Science.gov (United States)

    Manucha, Walter

    Multiple mechanisms underlying glutamate-induced neurotoxicity have recently been discussed. Likewise, a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with neurodegeneration, oxidative stress, and inflammation. This article highlights nitric oxide, an atypical neurotransmitter synthesized and released on demand by the post-synaptic neurons, and has many important implications for nerve cell survival and differentiation. Consequently, synaptogenesis, synapse elimination, and neurotransmitter release, are nitric oxide-modulated. Interesting, an emergent role of nitric oxide pathways has been discussed as regards neurotoxicity from glutamate-induced apoptosis. These findings suggest that nitric oxide pathways modulation could prevent oxidative damage to neurons through apoptosis inhibition. This review aims to highlight the emergent aspects of nitric oxide-mediated signaling in the brain, and how they can be related to neurotoxicity, as well as the development of neurodegenerative diseases development. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Investigation on oxidative stress of nitric oxide synthase interacting protein from Clonorchis sinensis.

    Science.gov (United States)

    Bian, Meng; Xu, Qingxia; Xu, Yanquan; Li, Shan; Wang, Xiaoyun; Sheng, Jiahe; Wu, Zhongdao; Huang, Yan; Yu, Xinbing

    2016-01-01

    Numerous evidences indicate that excretory-secretory products (ESPs) from liver flukes trigger the generation of free radicals that are associated with the initial pathophysiological responses in host cells. In this study, we first constructed a Clonorchis sinensis (C. sinensis, Cs)-infected BALB/c mouse model and examined relative results respectively at 3, 5, 7, and 9 weeks postinfection (p.i.). Quantitative reverse transcription (RT)-PCR indicated that the transcriptional level of both endothelial nitric oxide synthase (eNOS) and superoxide dismutase (SOD) gradually decreased with lastingness of infection, while the transcriptional level of inducible NOS (iNOS) significantly increased. The level of malondialdehyde (MDA) in sera of infected mouse significantly increased versus the healthy control group. These results showed that the liver of C. sinensis-infected mouse was in a state with elevated levels of oxidation stress. Previously, C. sinensis NOS interacting protein coding gene (named CsNOSIP) has been isolated and recombinant CsNOSIP (rCsNOSIP) has been expressed in Escherichia coli, which has been confirmed to be a component present in CsESPs and confirmed to play important roles in immune regulation of the host. In the present paper, we investigated the effects of rCsNOSIP on the lipopolysaccharide (LPS)-induced activated RAW264.7, a murine macrophage cell line. We found that endotoxin-free rCsNOSIP significantly promoted the levels of nitric oxide (NO) and reactive oxygen species (ROS) after pretreated with rCsNOSIP, while the level of SOD decreased. Furthermore, rCsNOSIP could also increase the level of lipid peroxidation MDA. Taken together, these results suggested that CsNOSIP was a key molecule which was involved in the production of nitric oxide (NO) and its reactive intermediates, and played an important role in oxidative stress during C. sinensis infection.

  18. Nitric Oxide in Astrocyte-Neuron Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nianzhen [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca2+ elevations in response to neurotransmitters. A Ca2+ elevation can propagate to adjacent astrocytes as a Ca2+ wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca2+-dependent mechanism, thus modulating neuronal activity and synaptic transmission. In this dissertation, the author investigated the roles of another endogenous signal, nitric oxide (NO), in astrocyte-neuron signaling. First the author tested if NO is generated during astrocytic Ca2+ signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a natural messenger, ATP, caused a Ca2+-dependent NO production. To test the roles of NO in astrocytic Ca2+ signaling, the author applied NO to astrocyte cultures via addition of a NO donor, S-nitrosol-N-acetylpenicillamine (SNAP). NO induced an influx of external Ca2+, possibly through store-operated Ca2+ channels. The NO-induced Ca2+ signaling is cGMP-independent since 8-Br-cGMP, an agonistic analog of cGMP, did not induce a detectable Ca2+ change. The consequence of this NO-induced Ca2+ influx was assessed by simultaneously monitoring of cytosolic and internal store Ca2+ using fluorescent Ca2+ indicators x-rhod-1 and mag-fluo-4. Blockage of NO signaling with the NO scavenger PTIO significantly reduced the refilling percentage of internal stores following ATP-induced Ca2+ release, suggesting that NO modulates internal store refilling. Furthermore, locally photo-release of NO to a single astrocyte led to a Ca2+ elevation in the stimulated astrocyte and a subsequent Ca2+ wave to neighbors. Finally, the author tested the role of NO inglutamate-mediated astrocyte-neuron signaling by

  19. Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

    Science.gov (United States)

    Benzing, A; Loop, T; Mols, G; Geiger, K

    1999-10-01

    Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the

  20. Synthesis of highly efficient Mn{sub 2}O{sub 3} catalysts for CO oxidation derived from Mn-MIL-100

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaodong, E-mail: fatzhxd@126.com [Environment and Low-Carbon Research Center, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China); Li, Hongxin; Hou, Fulin; Yang, Yang; Dong, Han; Liu, Ning [Environment and Low-Carbon Research Center, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China); Wang, Yuxin [Institute of Applied Biotechnology, Taizhou Vocation & Technical College, Taizhou, Zhejiang 318000 (China); Cui, Lifeng, E-mail: lifeng.cui@gmail.com [Environment and Low-Carbon Research Center, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2017-07-31

    Highlights: • The morphology of porous Mn{sub 2}O{sub 3} cubes was inherited from Mn-MIL-100 template. • Mn{sub 2}O{sub 3} obtained at calcined temperature of 700 °C displayed high activity. • Enhanced activity is attributed to surface active oxygen, and reduction behavior. - Abstract: In this work, metal-organic frameworks (MOFs) Mn-MIL-100 were first prepared, which were next used as templates to obtain the irregular porous Mn{sub 2}O{sub 3} cubes through calcination with air at different temperature. The catalysts were characterized by N{sub 2} adsorption-desorption, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), H{sub 2}-temperature program reduction (H{sub 2}-TPR) and X-ray photoelectron spectroscopic (XPS). The catalytic activity for CO oxidation over Mn{sub 2}O{sub 3} catalysts was investigated. It was found that calcination temperature had a strong effect on the structure and catalytic activity of Mn{sub 2}O{sub 3} catalyst. Mn{sub 2}O{sub 3} catalyst obtained by calcined at 700 °C (Mn{sub 2}O{sub 3}-700) showed a smaller specific surface area, but displayed a high catalytic activity and excellent stability with a complete CO conversion temperature (T{sub 98}) of 240 °C, which was attributed to the unique structure, a high quantity of surface active oxygen species, smaller particle size, oxygen vacancies and good low temperature reduction behavior. The effect of water vapor on catalytic activity was also examined. The introduction of water vapor to the feedstock induced a positive effect on CO oxidation over Mn{sub 2}O{sub 3}-700 catalyst. Furthermore, no obvious drop is observed in activity over catalysts even in the presence of water vapor during 48 h.

  1. Pain modulation by nitric oxide in the spinal cord.

    Directory of Open Access Journals (Sweden)

    Marco Aurelio M Freire

    2009-09-01

    Full Text Available Nitric oxide (NO is a versatile messenger molecule first associated with endothelial relaxing effects. In the central nervous system (CNS, NO synthesis is primarily triggered by activation of N-methyl-D-aspartate (NMDA receptors and has a Janus face, with both beneficial and harmful properties, depending on concentration and the identity of its synthetic enzyme isoform. There are three isoforms of the NO synthesizing enzyme nitric oxide synthase (NOS: neuronal (nNOS, endothelial (eNOS, and inducible nitric oxide synthase (iNOS, each one involved with specific events in the brain. In CNS, nNOS is involved with modulation of synaptic transmission through long-term potentiation in several regions, including nociceptive circuits in the spinal cord. Here, we review the role played by NO on central pain sensitization.

  2. Vapor-liquid equilibria for nitric acid-water and plutonium nitrate-nitric acid-water solutions

    International Nuclear Information System (INIS)

    Maimoni, A.

    1980-01-01

    The liquid-vapor equilibrium data for nitric acid and nitric acid-plutnonium nitrate-water solutions were examined to develop correlations covering the range of conditions encountered in nuclear fuel reprocessing. The scanty available data for plutonium nitrate solutions are of poor quality but allow an order of magnitude estimate to be made. A formal thermodynamic analysis was attempted initially but was not successful due to the poor quality of the data as well as the complex chemical equilibria involved in the nitric acid and in the plutonium nitrate solutions. Thus, while there was no difficulty in correlating activity coefficients for nitric acid solutions over relatively narrow temperature ranges, attempts to extend the correlations over the range 25 0 C to the boiling point were not successful. The available data were then analyzed using empirical correlations from which normal boiling points and relative volatilities can be obtained over the concentration ranges 0 to 700 g/l Pu, 0 to 13 M nitric acid. Activity coefficients are required, however, if estimates of individual component vapor pressures are needed. The required ternary activity coefficients can be approximated from the correlations

  3. Zinc thiolate reactivity toward nitrogen oxides: insights into the interaction of Zn2+ with S-nitrosothiols and implications for nitric oxide synthase.

    Science.gov (United States)

    Kozhukh, Julia; Lippard, Stephen J

    2012-07-02

    Zinc thiolate complexes containing N(2)S tridentate ligands were prepared to investigate their reactivity toward reactive nitrogen species, chemistry proposed to occur at the zinc tetracysteine thiolate site of nitric oxide synthase (NOS). The complexes are unreactive toward nitric oxide (NO) in the absence of dioxygen, strongly indicating that NO cannot be the species directly responsible for S-nitrosothiol formation and loss of Zn(2+) at the NOS dimer interface in vivo. S-Nitrosothiol formation does occur upon exposure of zinc thiolate solutions to NO in the presence of air, however, or to NO(2) or NOBF(4), indicating that these reactive nitrogen/oxygen species are capable of liberating zinc from the enzyme, possibly through generation of the S-nitrosothiol. Interaction between simple Zn(2+) salts and preformed S-nitrosothiols leads to decomposition of the -SNO moiety, resulting in release of gaseous NO and N(2)O. The potential biological relevance of this chemistry is discussed.

  4. Neurodevelopmental outcomes of premature infants treated with inhaled nitric oxide.

    Science.gov (United States)

    Mestan, Karen K L; Marks, Jeremy D; Hecox, Kurt; Huo, Dezheng; Schreiber, Michael D

    2005-07-07

    Chronic lung disease and severe intraventricular hemorrhage or periventricular leukomalacia in premature infants are associated with abnormal neurodevelopmental outcomes. In a previous randomized, controlled, single-center trial of premature infants with the respiratory distress syndrome, inhaled nitric oxide decreased the risk of death or chronic lung disease as well as severe intraventricular hemorrhage and periventricular leukomalacia. We hypothesized that infants treated with inhaled nitric oxide would also have improved neurodevelopmental outcomes. We conducted a prospective, longitudinal follow-up study of premature infants who had received inhaled nitric oxide or placebo to investigate neurodevelopmental outcomes at two years of corrected age. Neurologic examination, neurodevelopmental assessment, and anthropometric measurements were made by examiners who were unaware of the children's original treatment assignment. A total of 138 children (82 percent of survivors) were evaluated. In the group given inhaled nitric oxide, 17 of 70 children (24 percent) had abnormal neurodevelopmental outcomes, defined as either disability (cerebral palsy, bilateral blindness, or bilateral hearing loss) or delay (no disability, but one score of less than 70 on the Bayley Scales of Infant Development II), as compared with 31 of 68 children (46 percent) in the placebo group (relative risk, 0.53; 95 percent confidence interval, 0.33 to 0.87; P=0.01). This effect persisted after adjustment for birth weight and sex, as well as for the presence or absence of chronic lung disease and severe intraventricular hemorrhage or periventricular leukomalacia. The improvement in neurodevelopmental outcome in the group given inhaled nitric oxide was primarily due to a 47 percent decrease in the risk of cognitive impairment (defined by a score of less than 70 on the Bayley Mental Developmental Index) (P=0.03). Premature infants treated with inhaled nitric oxide have improved neurodevelopmental

  5. Unsymmetrical phosphate as extractant for the extraction of nitric acid

    International Nuclear Information System (INIS)

    Gaikwad, R.H.; Jayaram, R.V.

    2016-01-01

    Tri-n-butyl phosphate (TBP) was first used as an extractant in 1944, during Manhattan project for the separation of actinides and further explored by Warf in 1949 for the extraction of Ce(IV) from aqueous nitric acid. TBP was further used as an extractant in the Plutonium Uranium Recovery by Extraction (PUREX) process. To meet the stringent requirements of the nuclear industry TBP has been extensively investigated. In spite of its wide applicability, TBP suffers from various disadvantages such as high aqueous solubility, third phase formation, chemical and radiation degradation leading to the formation of undesired products. It also suffers from incomplete decontamination of the actinides from fission products. Various attempts have been made to overcome the problems associated with TBP by way of using higher homologues of TBP such as Tri-iso amyl phosphate (TiAP), Tri-secondary butyl phosphate (TsBP), Tri amyl phosphate (TAP). It was found that in some cases the results were considerably better than those obtained with TBP for uranium/thorium extraction. The extraction of nitric acid by TBP and its higher homologues which are symmetrical are well documented. However, no solvent has emerged clearly superior than TBP. Here in we report the extraction of nitric acid with neutral unsymmetrical phosphates and study them as extractants for the extraction of nitric acid. Dibutyl secbutyl phosphate, dibutyl pentyl phosphate and dibutyl heptyl phosphate were synthesised for this purpose and the extraction of nitric acid was studied in n-dodecane. The results indicate that the substitution of one of the alkyl groups of the symmetrical phosphate adjacent to the phosphoryl (P=O) group of the phosphate does not have any pronounced effect on the extraction capacity of nitric acid. (author)

  6. Refractory Oxide Coatings on Titanium for Nitric Acid Applications

    Science.gov (United States)

    Ravi Shankar, A.; Kamachi Mudali, U.

    2014-07-01

    Tantalum and Niobium have good corrosion resistance in nitric acid as well as in molten chloride salt medium encountered in spent fuel nuclear reprocessing plants. Commercially, pure Ti (Cp-Ti) exhibits good corrosion resistance in nitric acid medium; however, in vapor condensates of nitric acid, significant corrosion was observed. In the present study, a thermochemical diffusion method was pursued to coat Ta2O5, Nb2O5, and Ta2O5 + Nb2O5 on Ti to improve the corrosion resistance and enhance the life of critical components in reprocessing plants. The coated samples were characterized by XRD, SEM, EDX, profilometry, micro-scratch test, and ASTM A262 Practice-C test in 65 pct boiling nitric acid. The SEM micrograph of the coated samples showed that uniform dense coating containing Ta2O5 and/or Nb2O5 was formed. XRD patterns indicated the formation of TiO2, Ta2O5/Nb2O5, and mixed oxide/solid solution phase on coated Ti samples. ASTM A262 Practice-C test revealed reproducible outstanding corrosion resistance of Ta2O5-coated sample in comparison to Nb2O5- and Ta2O5 + Nb2O5-coated sample. The hardness of the Ta2O5-coated Cp-Ti sample was found to be twice that of uncoated Cp-Ti. The SEM and XRD results confirmed the presence of protective oxide layer (Ta2O5, rutile TiO2, and mixed phase) on coated sample which improved the corrosion resistance remarkably in boiling liquid phase of nitric acid compared to uncoated Cp-Ti and Ti-5Ta-1.8Nb alloy. Three phase corrosion test conducted on Ta2O5-coated samples in boiling 11.5 M nitric acid showed poor corrosion resistance in vapor and condensate phases of nitric acid due to poor adhesion of the coating. The adhesive strength of the coated samples needs to be optimized in order to improve the corrosion resistance in vapor and condensate phases of nitric acid.

  7. Corrosion resistance of zirconium: general mechanisms, behaviour in nitric acid

    International Nuclear Information System (INIS)

    Pinard Legry, G.

    1990-01-01

    Corrosion resistance of zirconium results from the strong affinity of this metal for oxygen; as a result a thin protective oxide film is spontaneously formed in air or aqueous media, its thickness and properties depending on the physicochemical conditions at the interface. This film passivates the underlying metal but obviously if the passive film is partially or completely removed, localised or generalised corrosion phenomena will occur. In nitric acid, this depassivation may be chemical (fluorides) or mechanical (straining, creep, fretting). In these cases it is useful to determine the physicochemical conditions (concentration, temperature, potential, stress) which will have to be observed to use safely zirconium and its alloys in nitric acid solutions [fr

  8. Nitric oxide: Orchestrator of endothelium-dependent responses

    DEFF Research Database (Denmark)

    Félétou, Michel; Köhler, Ralf; Vanhoutte, Paul M

    2012-01-01

    Abstract The present review first summarizes the complex chain of events, in endothelial and vascular smooth muscle cells, that leads to endothelium-dependent relaxations (vasodilatations) due to the generation of nitric oxide (NO) by endothelial nitric oxide synthase (eNOS) and how therapeutic...... interventions may improve the bioavailability of NO and thus prevent/cure endothelial dysfunction. Then, the role of other endothelium-derived mediators (endothelium-derived hyperpolarizing (EDHF) and contracting (EDCF) factors, endothelin-1) and signals (myoendothelial coupling) is summarized also...

  9. Nitric oxide-induced signalling in rat lacrimal acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia Karen; Tritsaris, K.; Dissing, S.

    2002-01-01

    The aim of the present study was to investigate the physiological role of nitric oxide (NO) in mediating secretory processes in rat lacrimal acinar cells. In addition, we wanted to determine whether the acinar cells possess endogenous nitric oxide synthase (NOS) activity by measuring NO productio...... using the fluorescent NO indicator 4,5-diaminofluorescein (DAF-2). We initiated investigations by adding NO from an external source by means of the NO-donor, S-nitroso-N-acetyl-penicillamine (SNAP). Cellular concentrations of cyclic guanosine 5'-phosphate (cGMP) ([cGMP]) were measured...

  10. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  11. Adsorption of NI (II on activated Carbon of Coconut shell Chemicaly Modifieded with Acid Nitric Solutions

    Directory of Open Access Journals (Sweden)

    Mónica Hernández-Rodríguez

    2017-01-01

    Full Text Available In the research the effect of modification of coconut shell activated carbon with diluted solutions of nitric acid, in its chemical characteristics and removal capacity of the nickel (II ions present in modeling solutions of sulfates with similar characteristics to the acid liquor waste of the nickel industry, was studied. The characterization of the adsorbent material evidenced that the modification process increases the superficial acids groups according with the increase of acid nitric concentration employee in the treatment. The adsorption equilibrium tests, carried out with metallic species solutions at concentrations between 0,5 and 3,5 g/L evidenced that the process is described by Freundlich model. The effect of chemical modification of the adsorbent material in adsorption capacity of nickel (II ions was evaluated using a traditional experimental design at pH of 1,2 and 6,9 units, obtaining that the increase of acid groups in the carbon surface causes an increase of adsorption capacity and removal percentages of nickel (II, due to specific interactions of these groups with the metal cations.

  12. Nitric oxide-releasing polyacrylonitrile disperses biofilms formed by wound-relevant pathogenic bacteria.

    Science.gov (United States)

    Craven, M; Kasper, S H; Canfield, M J; Diaz-Morales, R R; Hrabie, J A; Cady, N C; Strickland, A D

    2016-04-01

    To test the antimicrobial and antibiofilm properties of a nitric oxide (NO)-releasing polymer against wound-relevant bacterial pathogens. Using a variety of 96-well plate assay systems that include standard well plates and the minimum biofilm eradication concentration biofilm assay well plate, a NO-releasing polymer based on (poly)acrylonitrile (PAN/NO) was studied for antimicrobial and antibiofilm activity against the common wound pathogens Pseudomonas aeruginosa (PAO1), Staphylococcus aureus (Mu50) and Enterococcus faecalis (V583). The polymer was capable of dispersing single-species biofilms of Ps. aeruginosa as well as a more clinically relevant multispecies biofilm that incorporates Ps. aeruginosa along with Staph. aureus and Ent. faecalis. PAN/NO also synergistically enhanced the susceptibility of the multispecies biofilms to the common broad-spectrum antibiotic, ciprofloxacin. Multiple in vitro biocompatibility assays show that PAN/NO has limited potential for mammalian cytotoxicity. This study demonstrates the feasibility of utilizing the NO-releasing polymer, PAN/NO, to manage biofilms formed by wound-relevant pathogens, and provides proof-of-concept for use of this NO-releasing polymer platform across multiple disciplines where bacterial biofilms pose significant problems. In the clinical sector, bacterial biofilms represent a substantial treatment challenge for health care professionals and are widely recognized as a key factor in prolonging patient morbidity. This study highlights the potential role for the ubiquitous signalling molecule nitric oxide (NO) as an antibiofilm therapy. © 2016 The Society for Applied Microbiology.

  13. Spectroscopic Temperature and Number Density of Nitric Oxide in Laser-Induced Plasma

    Science.gov (United States)

    Fleischmann, Josef P.; Swafford, Lauren D.; Witte, Michael J.; Surmick, David M.; Woods, Alexander C.; Behery, Sultan A.; Parigger, Christian G.; Hornkohl, James O.

    2014-03-01

    We report measurements of nitric oxide emission spectra subsequent to infra-red Nd:YAG laser-induced breakdown in air. Plasma is generated by focusing 160 mJ energy per pulse, 13 ns pulse-width, laser radiation at a wavelength of 1064 nm. The NO emissions are recorded for time delays of 25, 50, and 75 μs after plasma generation, utilizing a 0.64 meter Czerny-Turner type spectrometer with a 3600 grooves/mm grating, and an intensified linear diode array. The analysis utilizes accurate line strengths for selected bands in the ultraviolet region of 205 to 300 nm. Temperatures on the order of 6000 to 7000 Kelvin are inferred from the emission spectra. Comparisons are included with previous experimental studies in 1:1 mixture of N2:O2, where we deduced temperature and species densities using plasma predictions for various conditions and a so-called non-equilibrium air radiation code. The current work elaborates on details of two specific NO bands to evaluate as well accuracy of our line strength data. While the presented spectra, recorded in laser-induced plasma in air, are due to recombination processes following optical breakdown, results of our work on diatomic nitric oxide emissions are expected to be also applicable in chemical physics investigations of combustion.

  14. The endogenous nitric oxide mediates selenium-induced phytotoxicity by promoting ROS generation in Brassica rapa.

    Directory of Open Access Journals (Sweden)

    Yi Chen

    Full Text Available Selenium (Se is suggested as an emerging pollutant in agricultural environment because of the increasing anthropogenic release of Se, which in turn results in phytotoxicity. The most common consequence of Se-induced toxicity in plants is oxidative injury, but how Se induces reactive oxygen species (ROS burst remains unclear. In this work, histofluorescent staining was applied to monitor the dynamics of ROS and nitric oxide (NO in the root of Brassica rapa under Se(IV stress. Se(IV-induced faster accumulation of NO than ROS. Both NO and ROS accumulation were positively correlated with Se(IV-induced inhibition of root growth. The NO accumulation was nitrate reductase (NR- and nitric oxide synthase (NOS-dependent while ROS accumulation was NADPH oxidase-dependent. The removal of NO by NR inhibitor, NOS inhibitor, and NO scavenger could alleviate Se(IV-induced expression of Br_Rbohs coding for NADPH oxidase and the following ROS accumulation in roots, which further resulted in the amelioration of Se(IV-induced oxidative injury and growth inhibition. Thus, we proposed that the endogenous NO played a toxic role in B. rapa under Se(IV stress by triggering ROS burst. Such findings can be used to evaluate the toxic effects of Se contamination on crop plants.

  15. Raman spectroscopic study of the aging and nitration of actinide processing anion-exchange resins in concentrated nitric acid

    International Nuclear Information System (INIS)

    Buscher, C. T.; Donohoe, R. J.; Mecklenburg, S. L.; Berg, J. M.; Tait, C. D.; Huchton, K. M.; Morris, D. E.

    1999-01-01

    Degradation of two types of anion exchange resins, Dowex 11 and Reillex HPQ, from the action of concentrated nitric acid (4 to 12 M) and radiolysis [from depleted uranium as UO 2 2+ nitrate species and 239 Pu as Pu(IV) nitrate species] was followed as a function of time with Raman vibrational spectroscopy. Elevated temperatures (∼50 degree sign C) were used in the absence of actinide metal loading to simulate longer exposures of the resin to a HNO 3 process stream and waste storage conditions. In the absence of actinide loading, only minor changes in the Dowex resin at acid concentrations ≤10 M were observed, while at 12 M acid concentration, the emergence of a Raman peak at 1345 cm-1 indicates the addition of nitro functional groups to the resin. Similar studies with the Reillex resin show it to be more resistant to nitric acid attack at all acid concentrations. Incorporation of weakly radioactive depleted uranium as the UO 2 2+ nitrate species to the ion-exchange sites of Dowex 11 under differing nitric acid concentrations (6 to 12 M) at room temperature showed no Raman evidence of resin degradation or nitration, even after several hundred days of contact. In contrast, Raman spectra for Dowex 11 in the presence of 239 Pu as Pu(IV) nitrate species reveal numerous changes indicating resin alterations, including a new mode at 1345 cm-1 consistent with a Pu(IV)-nitrate catalyzed addition of nitro groups to the resin backbone. (c) 2000 Society for Applied Spectroscopy

  16. The nitric oxide hypothesis of aging.

    Science.gov (United States)

    McCann, S M; Licinio, J; Wong, M L; Yu, W H; Karanth, S; Rettorri, V

    1998-01-01

    Nitric oxide (NO), generated by endothelial (e) NO synthase (NOS) and neuronal (n) NOS, plays a ubiquitous role in the body in controlling the function of almost every, if not every, organ system. Bacterial and viral products, such as bacterial lipopolysaccharide (LPS), induce inducible (i) NOS synthesis that produces massive amounts of NO toxic to the invading viruses and bacteria, but also host cells by inactivation of enzymes leading to cell death. The actions of all forms of NOS are mediated not only by the free radical oxidant properties of this soluble gas, but also by its activation of guanylate cyclase (GC), leading to the production of cyclic guanosine monophosphate (cGMP) that mediates many of its physiological actions. In addition, NO activates cyclooxygenase and lipoxygenase, leading to the production of physiologically relevant quantities of prostaglandin E2 (PGE2) and leukotrienes. In the case of iNOS, the massive release of NO, PGE2, and leukotrienes produces toxic effects. Systemic injection of LPS causes induction of interleukin (IL)-1 beta mRNA followed by IL-beta synthesis that induces iNOS mRNA with a latency of two and four hours, respectively, in the anterior pituitary and pineal glands, meninges, and choroid plexus, regions outside the blood-brain barrier, and shortly thereafter, in hypothalamic regions, such as the temperature-regulating centers, paraventricular nucleus containing releasing and inhibiting hormone neurons, and the arcuate nucleus, a region containing these neurons and axons bound for the median eminence. We are currently determining if LPS similarly activates cytokine and iNOS production in the cardiovascular system and the gonads. Our hypothesis is that recurrent infections over the life span play a significant role in producing aging changes in all systems outside the blood-brain barrier via release of toxic quantities of NO. NO may be a major factor in the development of coronary heart disease (CHD). Considerable evidence

  17. Detection of nitric acid and nitric oxides in the terrestrial atmosphere in the middle-infrared spectral region

    Directory of Open Access Journals (Sweden)

    M. I. Blecka

    1996-11-01

    Full Text Available A proposal for combined space and ground-based observations of the vertical distributions and the column densities of nitric acid and nitric oxide concentrations in the earth's atmosphere is discussed. We focus on the aspects that are particular to the idea of correlative measurements: geometrical considerations, simulations of the solar absorption spectra in the middle-infrared region corresponding to the different observational geometries, and the associated retrieval methods. These studies are done specifically for the Belgian-French experiment MIRAS (MIR Infrared Atmospheric Spectrometer onboard the Russian Space Station MIR and correlative ground-based FTIR measurements in the Tatra mountains.

  18. Mono- and dinuclear non-heme iron–nitrosyl complexes: Models for key intermediates in bacterial nitric oxide reductases

    Energy Technology Data Exchange (ETDEWEB)

    Berto, Timothy C.; Speelman, Amy L.; Zheng, Sheng; Lehnert, Nicolai

    2013-01-01

    High-spin non-heme iron–nitrosyls are of direct interest to both the chemical and biological communities as these species exhibit interesting chemical properties and act as direct models for enzymatic intermediates. The electronic ground state of the ferrous NO complexes, {Fe–NO}7, is best described as high-spin FeIII antiferromagnetically coupled to NO-, generating the spectroscopically observed S = 3/2 ground state. These species have been identified as catalytically relevant to a variety of NO-reducing enzymes such as bacterial nitric oxide reductase (NorBC) and flavo(rubredoxin) nitric oxide reductase (FNOR). Recently, the corresponding one-electron reduced {Fe–NO}8 (nitroxyl) complexes have also been implicated as biologically significant species. In this review the available spectroscopic data for {Fe–NO}7 and {Fe–NO}8 mono- and dinuclear non-heme iron–nitrosyls are summarized, and the implications of these results with respect to the electronic structures and reactivities of these species, in particular towards NO reduction, are discussed.

  19. Nitric oxide donors (nitrates), L-arginine, or nitric oxide synthase inhibitors for acute stroke.

    Science.gov (United States)

    Bath, Philip Mw; Krishnan, Kailash; Appleton, Jason P

    2017-04-21

    Nitric oxide (NO) has multiple effects that may be beneficial in acute stroke, including lowering blood pressure, and promoting reperfusion and cytoprotection. Some forms of nitric oxide synthase inhibition (NOS-I) may also be beneficial. However, high concentrations of NO are likely to be toxic to brain tissue. This is an update of a Cochrane review first published in 1998, and last updated in 2002. To assess the safety and efficacy of NO donors, L-arginine, and NOS-I in people with acute stroke. We searched the Cochrane Stroke Group Trials Register (last searched 6 February 2017), MEDLINE (1966 to June 2016), Embase (1980 to June 2016), ISI Science Citation Indexes (1981 to June 2016), Stroke Trials Registry (searched June 2016), International Standard Randomised Controlled Trial Number (ISRCTN) (searched June 2016), Clinical Trials registry (searched June 2016), and International Clinical Trials Registry Platform (ICTRP) (searched June 2016). Previously, we had contacted drug companies and researchers in the field. Randomised controlled trials comparing nitric oxide donors, L-arginine, or NOS-I versus placebo or open control in people within one week of onset of confirmed stroke. Two review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, and extracted data. The review authors cross-checked data and resolved issues through discussion. We obtained published and unpublished data, as available. Data were reported as mean difference (MD) or odds ratio (OR) with 95% confidence intervals (CI). We included five completed trials, involving 4197 participants; all tested transdermal glyceryl trinitrate (GTN), an NO donor. The assessed risk of bias was low across the included studies; one study was double-blind, one open-label and three were single-blind. All included studies had blinded outcome assessment. Overall, GTN did not improve the primary outcome of death or dependency at the end of trial (modified Rankin Scale (m

  20. Reproducibility of exhaled nitric oxide measurements in overweight and obese adults

    NARCIS (Netherlands)

    Thijs, Willemien; de Mutsert, Renée; le Cessie, Saskia; Hiemstra, Pieter S.; Rosendaal, Frits R.; Middeldorp, Saskia; Rabe, Klaus F.

    2014-01-01

    Exhaled nitric oxide is a noninvasive measure of airway inflammation that can be detected by a handheld device. Obesity may influence the reproducibility of exhaled nitric oxide measurements, by - for instance - decreased expiratory reserve volume. We analyzed triple exhaled nitric oxide

  1. Nitric oxide in health and disease of the respiratory system

    NARCIS (Netherlands)

    Ricciardolo, Fabio L. M.; Sterk, Peter J.; Gaston, Benjamin; Folkerts, Gert

    2004-01-01

    During the past decade a plethora of studies have unravelled the multiple roles of nitric oxide (NO) in airway physiology and pathophysiology. In the respiratory tract, NO is produced by a wide variety of cell types and is generated via oxidation of l-arginine that is catalyzed by the enzyme NO

  2. Effects of nitric oxide modulating activities on development of enteric ...

    Indian Academy of Sciences (India)

    ... the enteric neural crest-derived cells (ENCCs), and many molecules and biochemical processes may be involved in its development. This study examined the effects of modulating embryonic nitric oxide (NO) activity on the intestinal motility induced by ENS. One-hundred-and-twenty fertilized chicken eggs were assigned ...

  3. Evaluation of serum nitric oxide before and after local ...

    African Journals Online (AJOL)

    Hoda Aly Abd-El Moety

    2012-10-06

    Oct 6, 2012 ... Objectives: Evaluation of serum nitric oxide before and after local radiofrequency thermal ablation for hepatocellular carcinoma. Subjects: Twenty patients with proven hepatocellular carcinoma and 15 healthy patients as controls were enrolled in the study. Abbreviations: NO, nitrous oxide; HCC, ...

  4. Aluminium dissolution for spray pulverization with nitric acid

    International Nuclear Information System (INIS)

    Rodrigo Otero, A.; Rodrigo Vilaseca, F.; Morales Calvo, G.

    1977-01-01

    A comparative study of the nitric acid dissolution of aluminium, by immersion and spray pulverization has been carried out in laboratory scale. As a result, the optimum operation conditions to control reaction in the plant are fixed. Operation costs are also evaluated. (author) [es

  5. Insecticidal, brine shrimp cytotoxicity, antifungal and nitric oxide free ...

    African Journals Online (AJOL)

    The crude methanolic extract and various fractions derived from the aerial parts of Myrsine africana were screened in vitro for possible insecticidal, antifungal, brine shrimp lethality and nitric oxide free radical scavenging activities. Low insecticidal activity (20 %) was shown by chloroform (CHCl3) and aqueous fractions ...

  6. Evaluation of Fractioned Nitric Oxide in Chronic Cough Patients

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... Paediatr. Respir Rev 2006;7:9-14. 29. Pedük Y. Evaluation of etiologies of chronic cough in children. 2013; Available from: https://tez.yok.gov.tr. 30. Keskin O. The importance of exhaled nitric oxide in asthma and its correlation with host and environmental factors. 2010;. Available from: https://tez.yok.gov.tr.

  7. Role of nitric oxide and endogenous antioxidants in thyroxine ...

    African Journals Online (AJOL)

    ... blood samples collected for haematological indices through cardiac puncture and their stomachs prepared for gross and microscopic examinations to assess gastric healing. Gastric tissue protein, malondialdehyde (MDA), Superoxide Dismutase (SOD), Catalase (CAT), and Nitric oxide (NO) were assessed as biomarkers ...

  8. Nitric oxide radical scavenging potential of some Elburz medicinal ...

    African Journals Online (AJOL)

    Some plants scavenge nitric oxide (NO) with high affinity. For this purpose, forty extracts from 26 medicinal plants, growing extensively in Elburz mountains, were evaluated for their NO scavenging activity. Total phenolic and flavonoid contents of these extracts were also measured by Folin Ciocalteu and AlCl3 colorimetric ...

  9. Methanol Extract of Codonopsis pilosula Inhibits Inducible Nitric ...

    African Journals Online (AJOL)

    Purpose: To evaluate the mechanism of antioxidant activity of the methanol extract of Codonopsis pilosula. Methods: Anti-oxidative properties were assessed by measuring free radical scavenging activity, nitric oxide (NO) levels, protein oxidation and reducing power, while the mechanism of antioxidative effect of ...

  10. Nitric oxide interferes with hypoxia signaling during colonic inflammation.

    Science.gov (United States)

    Caria, Cintia Rabelo e Paiva; Moscato, Camila Henrique; Tomé, Renata Bortolin Guerra; Pedrazzoli, José; Ribeiro, Marcelo Lima; Gambero, Alessandra

    2014-01-01

    Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs). Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. Colitis was induced by single (acute) or repeated (reactivated colitis) trinitrobenzenosulfonic acid administration in rats. In addition, one group of rats with reactivated colitis was also treated with Nw-Nitro-L-arginine methyl ester hydrochloride to block nitric oxide synthase. Colitis was assessed by macroscopic score and myeloperoxidase activity in the colon samples. Hypoxia was determined using the oxygen-dependent probe, pimonidazole. The expression of HIF-1α and HIF-induced factors (vascular endothelial growth factor - VEGF and apelin) was assessed using Western blotting. The single or repeated administration of trinitrobenzenosulfonic acid to rats induced colitis which was characterized by a high macroscopic score and myeloperoxidase activity. Hypoxia was observed with both protocols. During acute colitis, HIF-1α expression was not increased, but VEGF and apelin were increased. HIF-1α expression was inhibited during reactivated colitis, and VEGF and apelin were not increased. Nw-Nitro-L-arginine methyl ester hydrochloride blockade during reactivated colitis restored HIF-1α, VEGF and apelin expression. Nitric oxide could interfere with hypoxia signaling during reactivated colitis inflammation modifying the expression of proteins regulated by HIF-1α.

  11. The correlation between total antioxidant capacity and nitric oxide ...

    African Journals Online (AJOL)

    Sperm DNA quality is important in male fertility. Oxidative stress increases sperm DNA damages. Antioxidants decrease production of free radicals and scavenge them. Nitric oxide (NO) is a free radical which is produced by most cells and has a dual role on cells. Low concentrations of NO is essential in biology and ...

  12. Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 ...

    African Journals Online (AJOL)

    HP

    Purpose: To explore the antioxidant properties of the methanol extract of Pericarpium Zanthoxyli and its effect on inducible nitric oxide synthase (iNOS), cycleooxygenase-2 (COX-2) and lipopolysaccharides (LPS)-induced cell damage in macrophage cells. Methods: Anti-oxidant activities were tested by measuring free ...

  13. The role of nitrite in nitric oxide homeostasis

    DEFF Research Database (Denmark)

    Jensen, Frank Bo

    2009-01-01

    Nitrite is endogenously produced as an oxidative metabolite of nitric oxide, but it also functions as a NO donor that can be activated by a number of cellular proteins under hypoxic conditions. This article discusses the physiological role of nitrite and nitrite-derived NO in blood flow regulatio...

  14. Modulation of glucose uptake in adipose tissue by nitric oxide ...

    Indian Academy of Sciences (India)

    Madhu

    Karnieli E, Barzilai A, Rafaeloff R and Armoni M 1986 Distribution of glucose transporters in membrane fractions isolated from human adipose cells; relative to cell size; J. Clin. Invest. 78. 1051–1055. Li J, Hu X, Selvakumar P, Russell R R, Cushman S W, Holman. G D and Young L H 2004 Role of the nitric oxide pathway in.

  15. Nitric oxide inhibitory activity of Strychnos spinosa (loganiaceae ...

    African Journals Online (AJOL)

    Background: The study was aimed at determining the anti-inflammatory activity of fractions and extracts obtained from Strychnos spinosa leaves on a mediator of inflammation nitric oxide (NO). Materials and Methods: Leaves were extracted with acetone and separated into fractions with different polarities by solventsolvent ...

  16. Evaluation of Fractioned Nitric Oxide in Chronic Cough Patients ...

    African Journals Online (AJOL)

    Introduction: Cough exceeding 3-8 weeks was defined as chronic cough in various guides. Asthma is the most common cause of chronic-specific cough. Causes other than asthma include prolonged bacterial bronchitis and upper airway cough syndrome (UACS). Nitric oxide (NO) causes vascular smooth muscle relaxation, ...

  17. Endothelial nitric oxide synthase gene Glu298Asp polymorphism ...

    African Journals Online (AJOL)

    Preeclampsia (PE) is the most serious complication of pregnancy that causes maternal and fetal morbidity and mortality. Although the exact pathophysiology of PE is unknown, a large number of studies have shown that abnormalities in nitric oxide (NO) synthesis may contribute to the development of this disorder. There are ...

  18. Role of Endothelial Nitric Oxide Synthase Gene Polymorphisms ...

    African Journals Online (AJOL)

    Background: Previous studies indicated an association between endothelial nitric oxide synthase (eNOS) activity and maintenance of pregnancy, but it is rather controversial whether polymorphisms of the gene encoding for eNOS are associated with recurrent spontaneous abortions (RSAs). Aim: The aim was to investigate ...

  19. Variation of nitric oxide levels in imported Plasmodium falciparum ...

    African Journals Online (AJOL)

    Nitric oxide (NO) has been recognized during the past two decades as one of the most versatile players in the immune system. Even though the molecular mechanisms responsible by the naturally acquired immunity against malaria are still to be clarified, the production of NO seems to play an important role as a marker for ...

  20. RECOVERY OF ACTINIDES FROM AQUEOUS NITRIC ACID SOLUTIONS

    Science.gov (United States)

    Ader, M.

    1963-11-19

    A process of recovering actinides is presented. Tetravalent actinides are extracted from rare earths in an aqueous nitric acid solution with a ketone and back-extracted from the ketone into an aqueous medium. The aqueous actinide solution thus obtained, prior to concentration by boiling, is sparged with steam to reduce its ketone to a maximum content of 3 grams per liter. (AEC)

  1. Nitric oxide metabolites in goldfish under normoxic and hypoxic conditions

    DEFF Research Database (Denmark)

    Hansen, Marie N.; Jensen, Frank Bo

    2010-01-01

    Nitric oxide (NO), produced by nitric oxide synthases (NOS enzymes), regulates multiple physiological functions in animals. NO exerts its effects by binding to iron (Fe) of heme groups (exemplified by the activation of soluble guanylyl cyclase) and by S-nitrosylation of proteins – and it is metab......Nitric oxide (NO), produced by nitric oxide synthases (NOS enzymes), regulates multiple physiological functions in animals. NO exerts its effects by binding to iron (Fe) of heme groups (exemplified by the activation of soluble guanylyl cyclase) and by S-nitrosylation of proteins......) in multiple tissues of a non-mammalian vertebrate (goldfish) under normoxic and hypoxic conditions. NO metabolites were measured in blood (plasma and red cells) and heart, brain, gill, liver, kidney and skeletal muscle, using highly sensitive reductive chemiluminescence. The severity of the chosen hypoxia...... levels was assessed from metabolic and respiratory variables. In normoxic goldfish, the concentrations of NO metabolites in plasma and tissues were comparable with values reported in mammals, indicative of similar NOS activity. Exposure to hypoxia [at PO2 (partial pressure of O2) values close...

  2. Original Article Pubertal Development of Penile Nitric Oxide ...

    African Journals Online (AJOL)

    mn

    The discovery of nitric ox- ide (NO) as an intercellular messenger or neurotransmitter has opened a new era for identifying the important mechanisms under- ... le- vels were significantly lower in the 40d- old rats than in the 54d and 65d-old animals. (p<0.05), but there were no statistically signi- ficant differences between the ...

  3. Cellular inactivation of nitric oxide induces p53-dependent ...

    African Journals Online (AJOL)

    Conclusion: The data obtained provide insight into the mechanism of cell proliferation action of endogenous NO•, based on p53 status, and indicate manipulation of iNOS may offer exciting opportunities to improve the effectiveness of melanoma treatment. Keywords: Apoptosis, Human melanoma cells, Inducible nitric oxide ...

  4. Variation of nitric oxide levels in imported Plasmodium falciparum ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... ISSN 1684–5315 © 2008 Academic Journals. Full Length Research Paper. Variation of nitric oxide levels in imported Plasmodium falciparum malaria episodes. De Sousa, Karina*, Silva, Marcelo S. and Tavira, Luís T. Instituto de Higiene e Medicina Tropical, Centro de Malária e outras Doenças Tropicais, ...

  5. Localization of nitric oxide synthase in human skeletal muscle

    DEFF Research Database (Denmark)

    Frandsen, Ulrik; Lopez-Figueroa, M.; Hellsten, Ylva

    1996-01-01

    The present study investigated the cellular localization of the neuronal type I and endothelial type III nitric oxide synthase in human skeletal muscle. Type I NO synthase immunoreactivity was found in the sarcolemma and the cytoplasm of all muscle fibres. Stronger immunoreactivity was expressed ...

  6. Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect and the potential mechanisms of ginsenoside Rb1 on nitric oxide. (NO) production in chondrocytes. Methods: SW1353 chondrosarcoma cells were stimulated with interleukin-1β (IL-1β) in the presence of. 20, 40, 80 µM ginsenoside Rb1. NO concentration was assessed by the Griess ...

  7. Methodological aspects of exhaled nitric oxide measurements in infants.

    NARCIS (Netherlands)

    Gabriele, C.; Wiel, E.C. van der; Nieuwhof, E.M.; Moll, H.A.; Merkus, P.J.F.M.; Jongste, J.C. de

    2007-01-01

    Guidelines for the measurement of fractional exhaled nitric oxide (FE(NO)) recommend refraining from lung function tests (LFT) and certain foods and beverages before performing FE(NO) measurements, as they may lead to transiently altered FE(NO) levels. Little is known of such factors in infants. The

  8. Water vapour and carbon dioxide decrease nitric oxide readings

    NARCIS (Netherlands)

    vanderMark, TW; Kort, E; Meijer, RJ; Postma, DS; Koeter, GH

    Measurement of nitric oxide levels in exhaled ah-is commonly performed using a chemiluminescence detector. However, water vapour and carbon dioxide affect the chemiluminescence process, The influence of these gases at the concentrations present in exhaled air has not vet been studied. For this in

  9. Cellular inactivation of nitric oxide induces p53-dependent ...

    African Journals Online (AJOL)

    Purpose: To examine the role of endogenous nitric oxide (NO•) and influence of p53 status during apoptosis induced by a ... endogenous NO•, based on p53 status, and indicate manipulation of iNOS may offer exciting opportunities to improve the ..... agents, further research will be required to define more specifically the ...

  10. Expression of Inducible Nitric Oxide Synthase in the Epithelial ...

    African Journals Online (AJOL)

    Conclusion: iNOS was over expressed in OKCs when compared with DC and RC suggesting that iNOS may contribute to the aggressive behavior of OKC. This is yet another evidence to support that OKC is the neoplasm. Keywords: Dentigerous cyst, Immunohistochemistry, Inducible nitric oxide synthase, Odontogenic ...

  11. NITRIC OXIDE INTERFERES WITH HYPOXIA SIGNALING DURING COLONIC INFLAMMATION

    Directory of Open Access Journals (Sweden)

    Cintia Rabelo e Paiva CARIA

    2014-12-01

    Full Text Available Context Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs. Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. Objectives We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. Methods Colitis was induced by single (acute or repeated (reactivated colitis trinitrobenzenosulfonic acid administration in rats. In addition, one group of rats with reactivated colitis was also treated with Nw-Nitro-L-arginine methyl ester hydrochloride to block nitric oxide synthase. Colitis was assessed by macroscopic score and myeloperoxidase activity in the colon samples. Hypoxia was determined using the oxygen-dependent probe, pimonidazole. The expression of HIF-1α and HIF-induced factors (vascular endothelial growth factor - VEGF and apelin was assessed using Western blotting. Results The single or repeated administration of trinitrobenzenosulfonic acid to rats induced colitis which was characterized by a high macroscopic score and myeloperoxidase activity. Hypoxia was observed with both protocols. During acute colitis, HIF-1α expression was not increased, but VEGF and apelin were increased. HIF-1α expression was inhibited during reactivated colitis, and VEGF and apelin were not increased. Nw-Nitro-L-arginine methyl ester hydrochloride blockade during reactivated colitis restored HIF-1α, VEGF and apelin expression. Conclusions Nitric oxide could interfere with hypoxia signaling during reactivated colitis inflammation modifying the expression of proteins regulated by HIF-1α.

  12. Analysis of genetic variation of inducible nitric oxide synthase and ...

    African Journals Online (AJOL)

    The genetic diversity of 100 Malaysian native chickens was investigated using polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) for two candidate genes: inducible nitric oxide synthase (INOS) and natural resistance-associated macrophage protein 1 (NRAMP1). The two genes were selected ...

  13. Arginine, citrulline and nitric oxide metabolism in sepsis

    Science.gov (United States)

    Arginine has vasodilatory effects, via its conversion by nitric oxide (NO) synthase into NO, and immunomodulatory actions that play important roles in sepsis. Protein breakdown affects arginine availability, and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore a...

  14. Regulation and control of nitric oxide (NO) in macrophages

    DEFF Research Database (Denmark)

    Kovacevic, Zaklina; Sahni, Sumit; Lok, K.H.

    2017-01-01

    We recently demonstrated that a novel storage and transport mechanism for nitric oxide (NO) mediated by glutathione-S-transferase P1 (GSTP1) and multidrug resistance protein 1 (MRP1/ABCC1), protects M1-macrophage (M1-MØ) models from large quantities of endogenous NO. This system stores and transp...

  15. Variation of nitric oxide levels in imported Plasmodium falciparum ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... Nitric oxide (NO) has been recognized during the past two decades as one of the most versatile players in the immune system. Even though the molecular mechanisms responsible by the naturally acquired immunity against malaria are still to be clarified, the production of NO seems to play an important role.

  16. Restoration Of Glutamine Synthetase Activity, Nitric Oxide Levels ...

    African Journals Online (AJOL)

    Background: Propolis has been proposed to be protective on neurodegenerative disorders. To understand the neuroprotective effects of honeybee propolis, glutamine synthetase (GS) activity, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAS) were studied in different brain ...

  17. Nitric oxide synthase expression and enzymatic activity in multiple sclerosis

    DEFF Research Database (Denmark)

    Broholm, H; Andersen, B; Wanscher, B

    2004-01-01

    and endothelial nitric oxide synthase (NOS)], and enzymatic NO synthase activity. MRI guided biopsies documented more active plaques than macroscopic examination, and histological examination revealed further lesions. Inducible NOS (iNOS) was the dominant IR isoform, while reactive astrocytes were the dominant i...

  18. Extraction behavior of U(IV) from nitric acid medium using di-isodecyl phosphoric acid dissolved in dodecane

    International Nuclear Information System (INIS)

    Sujoy Biswas; Hareendran, K.N.; Roy, S.B.; Singh, D.K.; Sharma, J.N.

    2010-01-01

    Solvent extraction of U(VI) with di-isodecyl phosphoric acid (DIDPA)/dodecane from nitric acid medium has been investigated for a wide range of experimental conditions. Effect of various parameters including nitric acid concentration, DIDPA concentration, temperature, stripping agents, and other impurities like rear earths, transition metal ion, boron, aluminum ion on U(VI) extraction has been studied. The species extracted in the organic phase is found to be UO 2 (NO 3 )(HA 2 ) · H 2 A 2 at lower acidity ( 3 ). Increase in temperature lead to the decrease in extraction with the enthalpy change by ΔH = -16.27 kJ/mol. Enhancement in extraction of U(VI) from nitric acid medium was observed with the mixture of DIDPA and tri butyl phosphate (TBP). The stripping of U(VI) from organic phase (DIDPA-U(VI)/dodecane) with various reagents followed the order: 4 M H 2 SO 4 > 5% (NH 4 ) 2 CO 3 > 8 M HCl > 8 M HNO 3 > Water. High separation factors between U(VI) and impurities suggested that the use of DIDPA for purification of uranium from multi elements bearing solution. (author)

  19. Formation of reactive oxygen species in rat epithelial cells upon ...

    Indian Academy of Sciences (India)

    Unknown

    < 100 nm) that contributed 31% to the particle number. In our study, we investigated the influence of fly ash on the promotion of early inflammatory reactions like the formation of reactive oxygen species (ROS) in rat lung epithelial cells (RLE-6TN). Furthermore, we determined the formation of nitric oxide (NO). The cells show a.

  20. Formation of reactive oxygen species in rat epithelial cells upon ...

    Indian Academy of Sciences (India)

    In our study, we investigated the influence of fly ash on the promotion of early inflammatory reactions like the formation of reactive oxygen species (ROS) in rat lung epithelial cells (RLE-6TN). Furthermore, we determined the formation of nitric oxide (NO). The cells show a clear dose-response relationship concerning the ...

  1. Antiplasmodial activity of 3-trifluoromethyl-2-carbonylquinoxaline di-N-oxide derivatives Atividade antimalárica de derivados di-N-óxido de 3-trifluorometil-2-carbonilquinoxalina

    Directory of Open Access Journals (Sweden)

    Belén Zarranz

    2006-09-01

    Full Text Available The in vitro antiplasmodial activity of some 3-trifluoromethyl-2-carbonylquinoxaline di-N-oxide derivatives is reported. The evaluation was performed on cultures of FcB1 strain (chloroquine-resistant of P. falciparum and the most interesting compounds were then evaluated on MCF7 tumor cells in order to evaluate an index of selectivity. The 7-methyl (2b, 4b, 5b, 6b and nonsubstituted (3c, 4c, 5c quinoxaline 1,4-dioxide derivatives presented the best level of activity.Neste artigo descreve-se a atividade anti-Plasmodium falciparum de derivados 3-trifluorometil-2-carbonilquinoxalinas di-N-óxidos (2a-6g. A avaliação das propriedades farmacológicas dos derivados 2a-6g foi realizada em modelo in vitro de inibição de cepas P. falciparum FcB1 (cloroquina resistente em cultura celular, e sobre culturas de células tumorais MCF7, com a finalidade de estabelecer o índice de seletividade para os compostos mais promissores. Os derivados 7-metil (2b, 4b, 5b, 6b e não-substituído (3c, 4c, 5c apresentaram o melhor perfil de atividade.

  2. Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds

    Directory of Open Access Journals (Sweden)

    A.C. Pereira

    2011-09-01

    Full Text Available During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP production, which in turn leads to protein kinase G (PKG activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described.

  3. Nitric oxide regulates the heart by spatial confinement of nitric oxide synthase isoforms.

    Science.gov (United States)

    Barouch, Lili A; Harrison, Robert W; Skaf, Michel W; Rosas, Gisele O; Cappola, Thomas P; Kobeissi, Zoulficar A; Hobai, Ion A; Lemmon, Christopher A; Burnett, Arthur L; O'Rourke, Brian; Rodriguez, E Rene; Huang, Paul L; Lima, João A C; Berkowitz, Dan E; Hare, Joshua M

    2002-03-21

    Subcellular localization of nitric oxide (NO) synthases with effector molecules is an important regulatory mechanism for NO signalling. In the heart, NO inhibits L-type Ca2+ channels but stimulates sarcoplasmic reticulum (SR) Ca2+ release, leading to variable effects on myocardial contractility. Here we show that spatial confinement of specific NO synthase isoforms regulates this process. Endothelial NO synthase (NOS3) localizes to caveolae, where compartmentalization with beta-adrenergic receptors and L-type Ca2+ channels allows NO to inhibit beta-adrenergic-induced inotropy. Neuronal NO synthase (NOS1), however, is targeted to cardiac SR. NO stimulation of SR Ca2+ release via the ryanodine receptor (RyR) in vitro, suggests that NOS1 has an opposite, facilitative effect on contractility. We demonstrate that NOS1-deficient mice have suppressed inotropic response, whereas NOS3-deficient mice have enhanced contractility, owing to corresponding changes in SR Ca2+ release. Both NOS1-/- and NOS3-/- mice develop age-related hypertrophy, although only NOS3-/- mice are hypertensive. NOS1/3-/- double knockout mice have suppressed beta-adrenergic responses and an additive phenotype of marked ventricular remodelling. Thus, NOS1 and NOS3 mediate independent, and in some cases opposite, effects on cardiac structure and function.

  4. Interleukin 1 beta induces diabetes and fever in normal rats by nitric oxide via induction of different nitric oxide synthases

    DEFF Research Database (Denmark)

    Reimers, J I; Bjerre, U; Mandrup-Poulsen, T

    1994-01-01

    Substantial in vitro evidence suggests that nitric oxide may be a major mediator of interleukin 1 (IL-1) induced pancreatic beta-cell inhibition and destruction in the initial events leading to insulin-dependent diabetes mellitus. Using NG-nitro-L-arginine methyl ester, an inhibitor of both...

  5. Studies of dissolution solutions of ruthenium metal, oxide and mixed compounds in nitric acid

    Energy Technology Data Exchange (ETDEWEB)

    Mousset, F.; Eysseric, C.; Bedioui, F

    2004-07-01

    Ruthenium is one of the fission products generated by irradiated nuclear fuel. It is present throughout all the steps of nuclear fuel reprocessing-particularly during extraction-and requires special attention due to its complex chemistry and high {beta}{gamma} activity. An innovative electro-volatilization process is now being developed to take advantage of the volatility of RuO{sub 4} in order to eliminate it at the head end of the Purex process and thus reduce the number of extraction cycles. Although the process operates successfully with synthetic nitrato-RuNO{sup 3+} solutions, difficulties have been encountered in extrapolating it to real-like dissolution solutions. In order to better approximate the chemical forms of ruthenium found in fuel dissolution solutions, kinetic and speciation studies on dissolved species were undertaken with RuO{sub 2},xH{sub 2}O and Ru{sup 0} in nitric acid media. (authors)

  6. Studies of dissolution solutions of ruthenium metal, oxide and mixed compounds in nitric acid

    International Nuclear Information System (INIS)

    Mousset, F.; Eysseric, C.; Bedioui, F.

    2004-01-01

    Ruthenium is one of the fission products generated by irradiated nuclear fuel. It is present throughout all the steps of nuclear fuel reprocessing-particularly during extraction-and requires special attention due to its complex chemistry and high βγ activity. An innovative electro-volatilization process is now being developed to take advantage of the volatility of RuO 4 in order to eliminate it at the head end of the Purex process and thus reduce the number of extraction cycles. Although the process operates successfully with synthetic nitrato-RuNO 3+ solutions, difficulties have been encountered in extrapolating it to real-like dissolution solutions. In order to better approximate the chemical forms of ruthenium found in fuel dissolution solutions, kinetic and speciation studies on dissolved species were undertaken with RuO 2 ,xH 2 O and Ru 0 in nitric acid media. (authors)

  7. Chemical constituents of Marrubium vulgare as potential inhibitors of nitric oxide and respiratory burst.

    Science.gov (United States)

    Shaheen, Farzana; Rasoola, Shagufta; Shah, Zafar Ali; Soomro, Samreen; Jabeen, Almas; Mesaik, M Ahmed; Choudhary, M Iqbal

    2014-07-01

    Phytochemical investigation of the whole plant of Marrubium vulgare L., led to the isolation of three new secondary metabolites, 11-oxomarrubiin (1), vulgarcoside A (2) and 3-hydroxyapigenin-4'-O-(6"-O-p-coumaroyl)-beta-D-glucopyranoside (3), along with four known constituents 4-7 from the polar fractions of the methanolic extract. The structures of all compounds were deduced on the basis of NMR data and HRESI-MS measurements. The new constituents 1-3 exhibited moderate to low level of inhibition on nitric oxide (NO.) production. The compound 2 also showed a moderate inhibition on pro-inflammatory cytokine TNF-alpha. The new constituents 1-3 showed no inhibitory effect on Reactive Oxygen Species (ROS) production.

  8. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals

    DEFF Research Database (Denmark)

    Fago, Angela; Parraga, Daniel Garcia; Petersen, Elin E.

    2017-01-01

    in regulating blood flow, we measured concentration of nitrite and S-nitrosothiols (SNO), two metabolites of the vasodilator nitric oxide (NO), in the blood of 5 species of marine mammals differing in their dive duration: bottlenose dolphin, South American sea lion, harbor seal, walrus and beluga whale. We also...... examined oxygen affinity, sensitivity to 2,3-diphosphoglycerate (DPG) and nitrite reductase activity of the hemoglobin (Hb) to search for possible adaptive variations in these functional properties. We found levels of plasma and red blood cells nitrite similar to those reported for terrestrial mammals...... in blood oxygen affinity among diving mammals likely derive from phenotypic variations in red blood cell DPG levels. The nitrite reductase activities of the Hbs were overall slightly higher than that of human Hb, with the Hb of beluga whale, capable of longest dives, having the highest activity. Taken...

  9. Detection of nitric oxide in exhaled air using cavity enhanced absorption spectroscopy

    Science.gov (United States)

    Medrzycki, R.; Wojtas, J.; Rutecka, B.; Bielecki, Z.

    2013-07-01

    The article describes an application one of the most sensitive optoelectronic method - Cavity Enhanced Absorption Spectroscopy in investigation of nitric oxide in exhaled breath. Measurement of nitric oxide concentration in exhaled breath is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of nitric oxide by developed optoelectronic sensor the vibronic molecular transitions were used. The wavelength ranges of these transitions are situated in the infrared spectral region. A setup consists of the optoelectronic nitric oxide sensor integrated with sampling and sample conditioning unit. The constructed detection system provides to measure nitric oxide in a sample of 0-97% relative humidity.

  10. Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

    Energy Technology Data Exchange (ETDEWEB)

    Reger, Nina A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Meng, Wilson S. [Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282 (United States); Gawalt, Ellen S., E-mail: gawalte@duq.edu [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219 (United States)

    2017-04-15

    Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

  11. Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

    International Nuclear Information System (INIS)

    Reger, Nina A.; Meng, Wilson S.; Gawalt, Ellen S.

    2017-01-01

    Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

  12. Exhaled nitric oxide in children after accidental exposure to chlorine gas.

    Science.gov (United States)

    Grasemann, Hartmut; Tschiedel, Eva; Groch, Manuela; Klepper, Jörg; Ratjen, Felix

    2007-08-01

    Chronic exposure to chlorine gas has been shown to cause occupational asthma. Acute inhalation of chlorine is known to cause airway inflammation and induce airway nitric oxide formation. Exhaled nitric oxide may therefore be a marker of airway damage after chlorine gas exposure. After accidental chlorine gas exposure in a swimming pool, exhaled nitric oxide and pulmonary function were repeatedly measured in 18 children over a 1-mo period. Symptomatic children with impaired pulmonary function had higher nitric oxide levels on the day after the exposure compared to day 8 and day 28. Differences in exhaled nitric oxide were more pronounced at a higher exhalation flow compared to lower flow, suggesting peripheral rather than central airway damage. This was in accordance with the observed changes in pulmonary function. No changes in exhaled nitric oxide were seen in asymptomatic children. These data suggest that acute chlorine gas exposure results in a mild increase of exhaled nitric oxide in symptomatic children.

  13. Do tobacco stimulate the production of nitric oxide by up regulation of inducible nitric oxide synthesis in cancer: Immunohistochemical determination of inducible nitric oxide synthesis in oral squamous cell carcinoma - A comparative study in tobacco habituers and non-habituers

    Directory of Open Access Journals (Sweden)

    B Karthik

    2014-01-01

    Conclusions: The results of the present study indicate the enhanced expression in OSCC of tobacco habituers when compared to OSCC of tobacco non-habituers indicating the effect of tobacco on nitric oxide. Carcinogenic chemical compounds in Tobacco induce nitric oxide production by iNOS, by its tumor-promoting effects which may enhance the process of carcinogenesis.

  14. Nitric oxide inhibits topoisomerase II activity and induces resistance to topoisomerase II-poisons in human tumor cells.

    Science.gov (United States)

    Kumar, Ashutosh; Ehrenshaft, Marilyn; Tokar, Erik J; Mason, Ronald P; Sinha, Birandra K

    2016-07-01

    Etoposide and doxorubicin, topoisomerase II poisons, are important drugs for the treatment of tumors in the clinic. Topoisomerases contain several free sulfhydryl groups which are important for their activity and are also potential targets for nitric oxide (NO)-induced nitrosation. NO, a physiological signaling molecule nitrosates many cellular proteins, causing altered protein and cellular functions. Here, we have evaluated the roles of NO/NO-derived species in the activity/stability of topo II both in vitro and in human tumor cells, and in the cytotoxicity of topo II-poisons, etoposide and doxorubicin. Treatment of purified topo IIα with propylamine propylamine nonoate (PPNO), an NO donor, resulted in inhibition of both the catalytic and relaxation activity in vitro, and decreased etoposide-dependent cleavable complex formation in both human HT-29 colon and MCF-7 breast cancer cells. PPNO treatment also induced significant nitrosation of topo IIα protein in these human tumor cells. These events, taken together, caused a significant resistance to etoposide in both cell lines. However, PPNO had no effect on doxorubicin-induced cleavable complex formation, or doxorubicin cytotoxicity in these cell lines. Inhibition of topo II function by NO/NO-derived species induces significant resistance to etoposide, without affecting doxorubicin cytotoxicity in human tumor cells. As tumors express inducible nitric oxide synthase and generate significant amounts of NO, modulation of topo II functions by NO/NO-derived species could render tumors resistant to certain topo II-poisons in the clinic. Published by Elsevier B.V.

  15. Nitric oxide-induced interstrand cross-links in DNA.

    Science.gov (United States)

    Caulfield, Jennifer L; Wishnok, John S; Tannenbaum, Steven R

    2003-05-01

    The DNA damaging effects of nitrous acid have been extensively studied, and the formation of interstrand cross-links have been observed. The potential for this cross-linking to occur through a common nitrosating intermediate derived from nitric oxide is investigated here. Using a HPLC laser-induced fluorescence (LIF) system, the amount of interstrand cross-link formed on nitric oxide treatment of the 5'-fluorescein-labeled oligomer ATATCGATCGATAT was determined. This self-complimentary sequence contains two 5'-CG sequences, which is the preferred site for nitrous acid-induced cross-linking. Nitric oxide was delivered to an 0.5 mM oligomer solution at 15 nmol/mL/min to give a final nitrite concentration of 652 microM. The resulting concentration of the deamination product, xanthine, in this sample was found to be 211 +/- 39 nM, using GC/MS, and the amount of interstrand cross-link was determined to be 13 +/- 2.5 nM. Therefore, upon nitric oxide treatment, the cross-link is found at approximately 6% of the amount of the deamination product. Using this system, detection of the cross-link is also possible for significantly lower doses of nitric oxide, as demonstrated by treatment of the same oligomer with NO at a rate of 18 nmol/mL/min resulting in a final nitrite concentration of 126 microM. The concentration of interstrand cross-link was determined to be 3.6 +/- 0.1 nM in this sample. Therefore, using the same dose rate, when the total nitric oxide concentration delivered drops by a factor of approximately 5, the concentration of cross-link drops by a factor of about 4-indicating a qausi-linear response. It may now be possible to predict the number of cross-links in a small genome based on the number of CpG sequences and the yield of xanthine derived from nitrosative deamination.

  16. Reactivity of the uranium (U(IV)/U(VI)) and the plutonium (Pu(III)/Pu(IV)) in nitric aqueous solution under ultrasound

    International Nuclear Information System (INIS)

    Venault, L.

    1998-01-01

    To minimize the volumes of solid waste and industrial effluents generated at the end of cycle, particularly in the spent nuclear fuel reprocessing industry, research is currently under way on so-called innovative processes, designed to induce chemical reactions without adding reagent to the media. Among these processes, the use of ultrasound can prove advantageous, and the purpose of this study is to assess accurately the potential for its application. In the present context, this work shows that the transmission of an ultrasonic wave in aqueous nitric acid solution leads to: the accumulation of nitrous acid in solution, until a steady-sate concentration is reached; the removal of nitrogen monoxide and nitrogen dioxide in the gas stream. The initial kinetics of the formation of HNO 2 in solution was quantified as a function of the nitric acid concentration and the ultrasound intensity. It was also shown than an excess of nitrous acid in nitric solution decomposes under the effect of ultrasound. It is also possible to accumulate hydrogen peroxide in solution during the ultrasonic irradiation of aqueous nitric acid solutions in the presence of a chemical species N 2 H 5 + , NH 2 SO 3 H...) which reacts rapidly with HNO 2 , preventing the reduction of H 2 O 2 by HNO 2 . The mechanisms of HNO 2 formation and decomposition, and the mechanism of H 2 O 2 formation during the ultrasonic irradiation of aqueous nitric acid solutions, are presented. Control of H 2 O 2 or HNO 2 in a nitric acid medium under the effect of an ultrasonic wave can be exploited to control redox reactions of uranium and plutonium ions, particularly with respect to the oxidation of U and Pu (U(IV)→ U(IV) or Pu(III) → Pu(IV)) and the reduction of Pu (Pu(IV)→ Pu(III). The redox behavior of uranium and plutonium ions in aqueous nitric solution subject to an ultrasonic flux is interpreted in term of effects induced on the reaction medium, and reveals the potential for using ultrasound to cause

  17. Antenatal insults modify newborn olfactory function by nitric oxide produced from neuronal nitric oxide synthase.

    Science.gov (United States)

    Drobyshevsky, Alexander; Yu, Lei; Yang, Yirong; Khalid, Syed; Luo, Kehuan; Jiang, Rugang; Ji, Haitao; Derrick, Matthew; Kay, Leslie; Silverman, Richard B; Tan, Sidhartha

    2012-10-01

    Newborn feeding, maternal, bonding, growth and wellbeing depend upon intact odor recognition in the early postnatal period. Antenatal stress may affect postnatal odor recognition. We investigated the exact role of a neurotransmitter, nitric oxide (NO), in newborn olfactory function. We hypothesized that olfactory neuron activity depended on NO generated by neuronal NO synthase (NOS). Utilizing in vivo functional manganese enhanced MRI (MEMRI) in a rabbit model of cerebral palsy we had shown previously that in utero hypoxia-ischemia (H-I) at E22 (70% gestation) resulted in impaired postnatal response to odorants and poor feeding. With the same antenatal insult, we manipulated NO levels in the olfactory neuron in postnatal day 1 (P1) kits by administration of intranasal NO donors or a highly selective nNOS inhibitor. Olfactory function was quantitatively measured by the response to amyl acetate stimulation by MEMRI. The relevance of nNOS to normal olfactory development was confirmed by the increase of nNOS gene expression from fetal ages to P1 in olfactory epithelium and bulbs. In control kits, nNOS inhibition decreased NO production in the olfactory system and increased MEMRI slope enhancement. In H-I kits the MEMRI slope did not increase, implicating modification of endogenous NO-mediated olfactory function by the antenatal insult. NO donors as a source of exogenous NO did not significantly change function in either group. In conclusion, olfactory epithelium nNOS in newborn rabbits probably modulates olfactory signal transduction. Antenatal H-I injury remote from delivery may affect early functional development of the olfactory system by decreasing NO-dependent signal transduction. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Smoking and gingivitis: focus on inducible nitric oxide synthase, nitric oxide and basic fibroblast growth factor.

    Science.gov (United States)

    Özdemir, B; Özmeric, N; Elgün, S; Barış, E

    2016-10-01

    Periodontal disease pathogenesis has been associated with smoking. Gingivitis is a mild and reversible form of periodontal disease and it tends to progress to periodontitis only in susceptible individuals. In the present study, we aimed to examine the impact of smoking on host responses in gingivitis and to evaluate and compare the inducible nitric oxide synthase (iNOS) activity in gingival tissue and NO and basic fibroblast growth factor (bFGF) levels in the gingival crevicular fluid of patients with gingivitis and healthy individuals. Forty-one participants were assigned to the gingivitis-smoker (n = 13), gingivitis (n = 13), healthy-smoker (n = 7) and healthy groups (n = 8). Clinical indices were recorded; gingival biopsy and gingival crevicular fluid samples were obtained from papillary regions. iNOS expression was evaluated by immunohistochemical staining. The immunoreactive cells were semiquantitatively assessed. For the quantitative determination of nitrite and nitrate in gingival crevicular fluid, the NO assay kit was used. The amount of bFGF in gingival crevicular fluid was determined by enzyme-linked immunosorbent assay. The gingivitis-smoker group demonstrated a stronger iNOS expression than the non-smoker gingivitis group. iNOS expression intensity was lower in the non-smoker healthy group compared to that in healthy-smokers. No significant gingival crevicular fluid NO and bFGF level changes were observed between groups. Among patients with gingivitis, a positive correlation was detected between gingival crevicular fluid NO and bFGF levels (r = 0.806, p = 0.001). Our data suggest that smoking has significant effects on iNOS expression but not on gingival crevicular fluid NO or bFGF levels in healthy and patients with gingivitis. However, our results suggest that bFGF might be involved in the regulation of NO production via iNOS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Characterization of exhaled nitric oxide: introducing a new reproducible method for nasal nitric oxide measurements.

    Science.gov (United States)

    Palm, J P; Graf, P; Lundberg, J O; Alving, K

    2000-08-01

    Nitric oxide (NO) is present in the human nasal airways and has been suggested to originate primarily from the paranasal sinuses. The aim of this study was to establish a new and reproducible method for measurement of nasal NO. Through repeated single-breath measurements the intra- and inter-individual variations of NO levels in nasally (into a tightly fitting mask covering the nose) and orally exhaled air were determined in healthy humans. Variations due to the methods used were investigated. The contribution of oral NO to the nasal exhalations by introducing a mouthwash procedure was also studied. This study shows distinct individual values of NO in nasally and orally exhaled air of healthy humans. Some diurnal variability was also found with a rise in NO in nasally and orally exhaled air over the day, but no, or little, day-to-day variability when comparing the results from separate mornings. There was no correlation between NO levels in nasally and orally exhaled air, whereas there was a strong correlation between NO levels in air exhaled through the left and right nostril. The levels of NO in air exhaled at 0.17 L x s(-1) through either nostril separately were higher than in air exhaled at the same flow rate through both nostrils simultaneously. After the introduction of a mouthwash procedure the level of NO in orally, but not nasally exhaled air was reduced. To conclude the method using nasal exhalation into a nose mask is highly reproducible. It is also suggested that subtracting the level of NO in orally exhaled air, after mouthwash, from that in nasally exhaled air, would adequately reflect nasal NO levels.

  20. Calculation of HNO2 concentration from redox potential in HNO3-H2O system as an aid to understanding the cathodic reaction of nitric acid corrosion

    International Nuclear Information System (INIS)

    Takeuchi, Masayuki; Whillock, G.O.H.

    2002-01-01

    Nitrous acid affects the corrosion of metals such as stainless steels in nitric acid. However nitrous acid is not particularly stable in nitric acid and the analytical methods available are quite involved. Accordingly, the calculation of nitrous acid concentration from redox potential was tested in the HNO 3 -H 2 O system as a convenient in situ analysis method. The calculation process is based on Nernst's equation and the required thermodynamic data were obtained from published values. The available thermodynamic data allow calculation of nitrous acid concentration from 273K to 373K for 0%-100% HNO 3 . The redox potential was 8 kmol·m -3 HNO 3 under NO bubbling and the nitrous acid concentration was determined by a Colourimetric method. The calculated data were compared with the measured data and a good agreement was found. It was found that the corrosion potential of stainless steel is influenced by nitrous acid concentration in nitric acid solution. The calculation process is useful for in-situ analysis of nitrous acid species in HNO 3 -H 2 O system and understanding the behavior of the cathodic reaction associated with nitric acid corrosion. (author)

  1. Expression of the nos gene and firefly flashing: a test of the nitric-oxide-mediated flash control model.

    Science.gov (United States)

    Ohtsuki, Hajime; Yokoyama, Jun; Ohba, Nobuyoshi; Ohmiya, Yoshihiro; Kawata, Masakado

    2014-04-19

    Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and populations of the same species. Their lights are assumed to be biological properties that play important ecological and evolutionary roles. Some species in the Lampyridae emit periodic luminescence, the patterns of which are characterized by species-specific intervals. In previous work, it was predicted that the nitric oxide (NO) regulates the oxygen supply required for the bioluminescence reaction of fireflies. Here, the expression of the NO synthase (NOS) mRNA in some fireflies was examined to verify the predictive model of nitric-oxide-mediated flash control in these insects. The expression of the nos gene in the lantern organ was observed not only in nocturnal flashing species but also in diurnal non-flashing species. It was shown that the expression levels of nos were higher in the lantern of Luciola cruciata (Motschulsky) larvae, which that emits continuous light, than in other body parts, although expression in the lantern of the adults, who flash periodically, was not high. Furthermore, there was no significant difference in expression levels among adults of Luciola cruciata characterized by different flashing intervals. The data do not support the model of an NO-mediated flash control mechanism, during which oxygen becomes available for the luciferin-luciferase reaction through NO-mediated inhibition of mitochondrial respiration. It is also indicated that flash patterns do not co-vary with NOS production. However, high nos expression in the larval lantern suggests that NO may play a role in producing continuous light by functioning as a neurotransmitter signal for bioluminescence. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

  2. Former land-use and tree species affect nitrogen oxide emissions from a tropical dry forest.

    Science.gov (United States)

    Heather Erickson; Eric A. Davidson; Michael Keller

    2002-01-01

    Species composition in successional dry forests in the tropics varies widely, but the effect of this variation on biogeochemical processes is not well known. We examined fluxes of N oxides (nitrous and nitric oxide), soil N cycling, and litter chemistry (C/N ratio) in four successional dry forests on similar soils in western Puerto Rico with differing species...

  3. Fate of aliphatic compounds in nitric acid processing solutions

    International Nuclear Information System (INIS)

    Clark, W.E.; Howerton, W.B.

    1975-01-01

    The reaction of hyperazeotropic iodic acid-saturated nitric acid with short chain aliphatic iodides, nitrates, and acids was studied in order to determine the conditions for complete removal of organic materials from nitric acid systems. The aliphatic iodides are converted to the nitrates and the nitrates in strong HNO 3 are extensively converted into CO 2 and acids. The aliphatic acids are rather stable; acetic acid was unattacked by boiling in 20M HNO 3 and n-butyric acid was 80 percent unattacked. The dibasic acids oxalic and malonic are extensively attacked, but succinic acid is relatively stable. A wet oxidation method is successful in destroying acetic acid in 5 to 8M HNO 3 . (U.S.)

  4. Nitric oxide-related drug targets in headache

    DEFF Research Database (Denmark)

    Olesen, Jes

    2010-01-01

    SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so-called del......SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so...... another very likely new treatment. It is more unlikely that antagonism of cGMP or its formation will be feasible, but augmenting its breakdown via phosphodiesterase activation is a possibility, as well as other ways of inhibiting the NO-cGMP pathway....

  5. NITRIC OXIDE AND ENDOTHELIN-1 IN CHILDREN WITH DIGESTIVE DISORDERS

    Directory of Open Access Journals (Sweden)

    I. V. Panova

    2012-01-01

    Full Text Available The important part in the group of biological compounds, participating in the regulation of the functions of the gastro-intestinal tract, is assigned to endothelial factors because of their impact on the majority of physiological and pathophysiological processes of the digestive system. The article provides information about physiological role of nitric oxide and endothelin-1 and presents a review of scientific data on the participation of nitric oxide and endothelin-1 in the pathogenesis of many digestive system diseases, emphasizing chronic inflammatory disorders of the upper gastrointestinal tract. The authors accentuate the importance of endothelium endocrine function research in children with esophagogastroduodenal disorders at the beginning of puberty, which is the critical period of ontogenesis.

  6. Nitric-glycolic flowsheet testing for maximum hydrogen generation rate

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site is developing for implementation a flowsheet with a new reductant to replace formic acid. Glycolic acid has been tested over the past several years and found to effectively replace the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the chemical generation of hydrogen and ammonia, allows purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective adjustment of the SRAT/SME rheology, and is favorable with respect to melter flammability. The objective of this work was to perform DWPF Chemical Process Cell (CPC) testing at conditions that would bound the catalytic hydrogen production for the nitric-glycolic flowsheet.

  7. The Effect of Artemisia fragrans Willd: Essential Oil on Inducible Nitric Oxide Synthase Gene Expression and Nitric Oxide Production in Lipopolysaccharide-stimulated Murine Macrophage Cell Line.

    Science.gov (United States)

    Farghadan, Maryam; Ghafoori, Hosein; Vakhshiteh, Faezeh; Shahzadeh Fazeli, Seyed Abolhassan; Farzaneh, Parvaneh; Kokhaei, Parviz

    2016-12-01

    The genus Artemisia is estimated to comprise over 800 species with anti-cancer, anti-fungal, anti-oxidant and anti-inflammatory properties. Artemisia fragrans (A. fragrans), a species that belongs to genus Artemisia, is rich in monoterpenes and sesquiterpenes derivatives. Due to anti-inflammatory properties of monoterpenes and sesquiterpenes, we aimed to investigate the effect of A. fragrans essential oil on mRNA expression of inducible nitric oxide synthase (iNOS) gene and nitric oxide (NO) production in Lipopolysaccharide (LPS) -stimulated RAW264.7 cell line. NO, which is synthesized by iNOS, is the main macrophage-derived inflammatory mediator. The oil obtained from the A. fragrans was prepared from aerial parts of the plant. Chemical composition of essential oil was analyzed by gas chromatography-mass spectrometry (GC/MS).The cytotoxicity of various concentrations of essential oil was evaluated by mitochondrial reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test assay. The effect of different doses (1.75-7 mg/mL) of A. fragrans oil on mRNA expression of iNOS gene and NO production in LPS-stimulated RAW 264.7 cells was assessed by real-time PCR method and Griess reagent, respectively. In GC/MS analyses of A. fragrans oil, 32 compounds were identified. The main components of the oil were camphor and 1, 8-cineole. The results demonstrated that the essential oil of A. fragrans (1.75- 7 mg/mL), in a dose-dependent manner, inhibits mRNA expression of iNOS induced by LPS in the RAW264.7 cells without cytotoxic effect even at higher doses. The results of iNOS were consistent with the results of NO production. Our preliminary results suggest the possible anti-inflammatory effect of A. fragrans. Further studies are needed to determine the full pharmacokinetics of A. fragrans activity in vivo.

  8. Bacillus anthracis Co-Opts Nitric Oxide and Host Serum Albumin for Pathogenicity in Hypoxic Conditions

    Directory of Open Access Journals (Sweden)

    Stephen eSt John

    2013-05-01

    Full Text Available Bacillus anthracis is a dangerous pathogen of humans and many animal species. Its virulence has been mainly attributed to the production of Lethal and Edema toxins as well as the antiphagocytic capsule. Recent data indicate that the nitric oxide (NO synthase (baNOS plays an important pathogenic role at the early stage of disease by protecting bacteria from the host reactive species and S-nytrosylating the mitochondrial proteins in macrophages. In this study we for the first time present evidence that bacteria-derived NO participates in the generation of highly reactive oxidizing species which could be abolished by the NOS inhibitor L-NAME, free thiols, and superoxide dismutase but not catalase. The formation of toxicants is likely a result of the simultaneous formation of NO and superoxide leading to a labile peroxynitrite and its stable decomposition product, nitrogen dioxide. The toxicity of bacteria could be potentiated in the presence of bovine serum albumin. This effect is consistent with the property of serum albumin to serves as a trap of a volatile NO accelerating its reactions. Our data suggest that during infection in the hypoxic environment of pre-mortal host the accumulated NO is expected to have a broad toxic impact on host cell functions.

  9. Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by ...

    African Journals Online (AJOL)

    Inhibition of Nitric Oxide and Prostaglandin E2 Expression by Methanol Extract of Polyopes affinis in Lipopolysaccharide-stimulated BV2 Microglial Cells through Suppression of Akt-dependent NF-kB Activity and MAPK Pathway. RGPT Jayasooriya, Y-J Jang, C-H Kang, MG Dilshara, D-O Moon, T-J Nam, YH Choi, G-Y Kim ...

  10. Diazeniumdiolated carbamates: a novel class of nitric oxide donors.

    Science.gov (United States)

    Nandurdikar, Rahul S; Maciag, Anna E; Cao, Zhao; Keefer, Larry K; Saavedra, Joseph E

    2012-03-15

    We report an indirect method for synthesis of previously inaccessible diazeniumdiolated carbamates. Synthesis involves use of previously reported triisopropylsilyloxymethylated isopropylamine diazeniumdiolate (TOM-ylated IPA/NO). These novel diazeniumdiolated carbamate prodrugs upon activation release nitric oxide (NO) similar to their secondary amine counterparts. They are also efficient sources of intracellular NO. These prodrugs may have potential applications as therapeutic NO-donors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Nitric oxide synthase expression and enzymatic activity in multiple sclerosis

    DEFF Research Database (Denmark)

    Broholm, H; Andersen, B; Wanscher, B

    2004-01-01

    We used post-mortem magnetic resonance imaging (MRI) guidance to obtain paired biopsies from the brains of four patients with clinical definite multiple sclerosis (MS). Samples were analyzed for the immunoreactivity (IR) of the three nitric oxide (NO) synthase isoforms [inducible, neuronal...... and sex showed no such changes. Our data support the hypothesis that NO is a pathogenic factor in MS, and that NOS IR is strongly expressed in brain regions appearing normal by MRI...

  12. Nitric oxide synthase isoforms in spontaneous and salt hypertension

    Czech Academy of Sciences Publication Activity Database

    Hojná, Silvie; Kuneš, Jaroslav; Zicha, Josef

    2007-01-01

    Roč. 25, Suppl. 2 (2007), S 338-S 338 ISSN 0263-6352. [European Meeting on Hypertension /17./. 15.06.2007-19.06.2007, Milan] R&D Projects: GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : nitric oxide synthase isoforms * spontaneous and salt hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  13. Nitric oxide and non-quantal acetylcholine release

    Czech Academy of Sciences Publication Activity Database

    Vyskočil, František

    2003-01-01

    Roč. 7, č. 3 (2003), s. 241-243 ISSN 1211-7579. [Celostátní konference biologické psychiatrie /11./. Luhačovice, 11.06.2003-14.06.2003] R&D Projects: GA ČR GA305/02/1333 Institutional research plan: CEZ:AV0Z5011922; CEZ:MSM 113100003 Keywords : nitric oxide Subject RIV: ED - Physiology

  14. Nitric oxide-related drug targets in headache

    DEFF Research Database (Denmark)

    Olesen, Jes

    2010-01-01

    SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so-called del......SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so......-called delayed headache that fulfils criteria for migraine without aura in migraine sufferers. Blockade of nitric oxide synthases (NOS) by L-nitromonomethylarginine effectively treats attacks of migraine without aura. Similar results have been obtained for chronic the tension-type headache and cluster headache....... Inhibition of the breakdown of cyclic guanylate phosphate (cGMP) also provokes migraine in sufferers, indicating that cGMP is the effector of NO-induced migraine. Similar evidence suggests an important role of NO in the tension-type headache and cluster headache. These very strong data from human...

  15. Exercise promotes collateral artery growth mediated by monocytic nitric oxide.

    Science.gov (United States)

    Schirmer, Stephan H; Millenaar, Dominic N; Werner, Christian; Schuh, Lisa; Degen, Achim; Bettink, Stephanie I; Lipp, Peter; van Rooijen, Nico; Meyer, Tim; Böhm, Michael; Laufs, Ulrich

    2015-08-01

    Collateral artery growth (arteriogenesis) is an important adaptive response to hampered arterial perfusion. It is unknown whether preventive physical exercise before limb ischemia can improve arteriogenesis and modulate mononuclear cell function. This study aimed at investigating the effects of endurance exercise before arterial occlusion on MNC function and collateral artery growth. After 3 weeks of voluntary treadmill exercise, ligation of the right femoral artery was performed in mice. Hindlimb perfusion immediately after surgery did not differ from sedentary mice. However, previous exercise improved perfusion restoration ≤7 days after femoral artery ligation, also when exercise was stopped at ligation. This was accompanied by an accumulation of peri-collateral macrophages and increased expression of endothelial nitric oxide synthase and inducible nitric oxide synthase (iNOS) in hindlimb collateral and in MNC of blood and spleen. Systemic monocyte and macrophage depletion by liposomal clodronate but not splenectomy attenuated exercise-induced perfusion restoration, collateral artery growth, peri-collateral macrophage accumulation, and upregulation of iNOS. iNOS-deficient mice did not show exercise-induced perfusion restoration. Transplantation of bone marrow-derived MNC from iNOS-deficient mice into wild-type animals inhibited exercise-induced collateral artery growth. In contrast to sedentary controls, thrice weekly aerobic exercise training for 6 months in humans increased peripheral blood MNC iNOS expression. Circulating mononuclear cell-derived inducible nitric oxide is an important mediator of exercise-induced collateral artery growth. © 2015 American Heart Association, Inc.

  16. Nitric oxide inhibits ATPase activity and induces resistance to topoisomerase II-poisons in human MCF-7 breast tumor cells.

    Science.gov (United States)

    Sinha, Birandra K; Kumar, Ashutosh; Mason, Ronald P

    2017-07-01

    Topoisomerase poisons are important drugs for the management of human malignancies. Nitric oxide ( • NO), a physiological signaling molecule, induces nitrosylation (or nitrosation) of many cellular proteins containing cysteine thiol groups, altering their cellular functions. Topoisomerases contain several thiol groups which are important for their activity and are also targets for nitrosation by nitric oxide. Here, we have evaluated the roles of • NO/ • NO-derived species in the stability and activity of topo II (α and β) both in vitro and in human MCF-7 breast tumor cells. Furthermore, we have examined the effects of • NO on the ATPase activity of topo II. Treatment of purified topo IIα and β with propylamine propylamine nonoate (PPNO), an NO donor, resulted in inhibition of the catalytic activity of topo II. Furthermore, PPNO significantly inhibited topo II-dependent ATP hydrolysis. • NO-induced inhibition of these topo II (α and β) functions resulted in a decrease in cleavable complex formation in MCF-7 cells in the presence of m-AMSA and XK469 and induced significant resistance to both drugs in MCF-7 cells. PPNO treatment resulted in the nitrosation of the topo II protein in MCF-7 cancer cells and inhibited both catalytic-, and ATPase activities of topo II. Furthermore, PPNO significantly affected the DNA damage and cytotoxicity of m-AMSA and XK469 in MCF-7 tumor cells. As tumors express nitric oxide synthase and generate • NO, inhibition of topo II functions by • NO/ • NO-derived species could render tumors resistant to certain topo II-poisons in the clinic.

  17. Experimental study on thermal hazard of tributyl phosphate-nitric acid mixtures using micro calorimeter technique

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qi; Jiang, Lin; Gong, Liang; Sun, Jin-Hua, E-mail: sunjh@ustc.edu.cn

    2016-08-15

    Highlights: • Heat flows after mixing TBP with nitric acid are of different orders of magnitude. • Thermodynamics and kinetics of tributyl phosphate-nitric acid mixtures are derived. • Tributyl phosphate directly reacts with nitric acid and form organic red oil. • Thermal runaway could occur at 79 °C with a high nitric acid concentration. - Abstract: During PUREX spent nuclear fuel reprocessing, mixture of tributyl phosphate (TBP) and hydrocarbon solvent are employed as organic solvent to extract uranium in consideration of radiation contaminated safety and resource recycling, meanwhile nitric acid is utilized to dissolve the spent fuel into small pieces. However, once TBP contacts with nitric acid or nitrates above 130 °C, a heavy “red oil” layer would occur accompanied by thermal runaway reactions, even caused several nuclear safety accident. Considering nitric acid volatility and weak exothermic detection, C80 micro calorimeter technique was used in this study to investigate thermal decomposition of TBP mixed with nitric acid. Results show that the concentration of nitric acid greatly influences thermal hazard of the system by direct reactions. Even with a low heating rate, if the concentration of nitric acid increases due to evaporation of water or improper operations, thermal runaway in the closed system could start at a low temperature.

  18. Flavone inhibits nitric oxide synthase (NOS) activity, nitric oxide production and protein S-nitrosylation in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenzhen; Yang, Bingwu; Fu, Huiling; Ma, Long; Liu, Tingting; Chai, Rongfei; Zheng, Zhaodi [Shandong Provincial Key Laboratory of Animal Resistant Biology, School of Life Sciences, Shandong Normal University, Jinan 250014 (China); Zhang, Qunye, E-mail: wz.zhangqy@sdu.edu.cn [Key Laboratory of Cardiovascular Remodeling and Function Research Chinese Ministry of Education and Ministry of Public Health, Qilu Hospital, Shandong University, Jinan, Shandong (China); Li, Guorong, E-mail: grli@sdnu.edu.cn [Shandong Provincial Key Laboratory of Animal Resistant Biology, School of Life Sciences, Shandong Normal University, Jinan 250014 (China)

    2015-03-13

    As the core structure of flavonoids, flavone has been proved to possess anticancer effects. Flavone's growth inhibitory functions are related to NO. NO is synthesized by nitric oxide synthase (NOS), and generally increased in a variety of cancer cells. NO regulates multiple cellular responses by S-nitrosylation. In this study, we explored flavone-induced regulations on nitric oxide (NO)-related cellular processes in breast cancer cells. Our results showed that, flavone suppresses breast cancer cell proliferation and induces apoptosis. Flavone restrains NO synthesis by does-dependent inhibiting NOS enzymatic activity. The decrease of NO generation was detected by fluorescence microscopy and flow cytometry. Flavone-induced inhibitory effect on NOS activity is dependent on intact cell structure. For the NO-induced protein modification, flavone treatment significantly down-regulated protein S-nitrosylation, which was detected by “Biotin-switch” method. The present study provides a novel, NO-related mechanism for the anticancer function of flavone. - Highlights: • Flavone inhibits proliferation and induces apoptosis in MCF-7 cells. • Flavone decreases nitric oxide production by inhibiting NOS enzymatic activity in breast cancer cells. • Flavone down-regulates protein S-nitrosylation.

  19. Inducible nitric oxide synthase (iNOS) regulatory region variation in non-human primates.

    Science.gov (United States)

    Roodgar, Morteza; Ross, Cody T; Kenyon, Nicholas J; Marcelino, Gretchen; Smith, David Glenn

    2015-04-01

    Inducible nitric oxide synthase (iNOS) is an enzyme that plays a key role in intracellular immune response against respiratory infections. Since various species of nonhuman primates exhibit different levels of susceptibility to infectious respiratory diseases, and since variation in regulatory regions of genes is thought to play a key role in expression levels of genes, two candidate regulatory regions of iNOS were mapped, sequenced, and compared across five species of nonhuman primates: African green monkeys (Chlorocebus sabaeus), pig-tailed macaques (Macaca nemestrina), cynomolgus macaques (Macaca fascicularis), Indian rhesus macaques (Macaca mulatta), and Chinese rhesus macaques (M. mulatta). In addition, we conducted an in silico analysis of the transcription factor binding sites associated with genetic variation in these two candidate regulatory regions across species. We found that only one of the two candidate regions showed strong evidence of involvement in iNOS regulation. Specifically, we found evidence of 13 conserved binding site candidates linked to iNOS regulation: AP-1, C/EBPB, CREB, GATA-1, GATA-3, NF-AT, NF-AT5, NF-κB, KLF4, Oct-1, PEA3, SMAD3, and TCF11. Additionally, we found evidence of interspecies variation in binding sites for several regulatory elements linked to iNOS (GATA-3, GATA-4, KLF6, SRF, STAT-1, STAT-3, OLF-1 and HIF-1) across species, especially in African green monkeys relative to other species. Given the key role of iNOS in respiratory immune response, the findings of this study might help guide the direction of future studies aimed to uncover the molecular mechanisms underlying the increased susceptibility of African green monkeys to several viral and bacterial respiratory infections. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Propolis attenuates oxidative injury in brain and lung of nitric oxide synthase inhibited rats

    Directory of Open Access Journals (Sweden)

    Zeliha Selamoglu-Talas

    2015-10-01

    Full Text Available Background: The blocking of nitric oxide synthase (NOS activity may reason vasoconstriction with formation of reactive oxygen species. Propolis has biological and pharmacological properties, such as antioxidant. The aim of this study was to examine the antioxidant effects of propolis which natural product on biochemical parameters in brain and lung tissues of acute nitric oxide synthase inhibited rats by Nω-nitro-L-arginine methyl ester (L-NAME.Methods: Rats have been received L-NAME (40 mg/kg, intraperitoneally, NOS inhibitor for 15 days to produce hypertension and propolis (200mg/kg, by gavage the lastest 5 of 15 days.Results: There  were  the  increase  (P<0.001  in  the  malondialdehyde  levels  in  the  L-NAME treatment groups when compared to control rats, but the decrease (P<0.001 in the catalase activities in both brain and lung tissues. There were statistically changes (P<0.001 in these parameters of L-NAME+propolis treated rats as compared with L-NAME-treated group.Conclusion: The application of L-NAME to the Wistar rats resulted in well developed oxidative stress. Also, propolis may influence endothelial NO production. Identification of such compounds and characterisation of their cellular actions may increase our knowledge of the regulation of endothelial NO production and could provide valuable clues for the prevention or treatment of hypertensive diseases and oxidative stress.

  1. Metabolism via arginase or nitric oxide synthase: two competing arginine pathways in macrophages

    Directory of Open Access Journals (Sweden)

    Meera eRath

    2014-10-01

    Full Text Available Macrophages play a major role in the immune system, both as antimicrobial effector cells and as immunoregulatory cells, which induce, suppress or modulate adaptive immune responses. These key aspects of macrophage biology are fundamentally driven by the phenotype of macrophage arginine metabolism that is prevalent in an evolving or ongoing immune response. M1 macrophages express the enzyme nitric oxide synthase (NOS, which metabolizes arginine to nitric oxide (NO and citrulline. NO can be metabolized to further downstream reactive nitrogen species, while citrulline might be reused for efficient NO synthesis via the citrulline-NO cycle. M2 macrophages are characterized by expression of the enzyme arginase, which hydrolyzes arginine to ornithine and urea. The arginase pathway limits arginine availability for NO synthesis and ornithine itself can further feed into the important downstream pathways of polyamine and proline syntheses, which are important for cellular proliferation and tissue repair. M1 versus M2 polarization leads to opposing outcomes of inflammatory reactions, but depending on the context, M1 and M2 macrophages can be both pro- and antiinflammatory. Notably, M1/M2 macrophage polarization can be driven by microbial infection or innate danger signals without any influence of adaptive immune cells, secondarily driving the T helper (Th1/Th2 polarization of the evolving adaptive immune response. Since both arginine metabolic pathways cross-inhibit each other on the level of the respective arginine break-down products and Th1 and Th2 lymphocytes can drive or amplify macrophage M1/M2 dichotomy via cytokine activation, this forms the basis of a self-sustaining M1/M2 polarization of the whole immune response. Understanding the arginine metabolism of M1/M2 macrophage phenotypes is therefore central to find new possibilities to manipulate immune responses in infection, autoimmune diseases, chronic inflammatory conditions and cancer.

  2. Development of radiation-inducible promoters for use in nitric oxide synthase gene therapy of cancer

    International Nuclear Information System (INIS)

    Hirst, D.G.; Worthington, J.; Adams, C.; Robson, T.; Scott, S.D.

    2003-01-01

    Full text: The free radical nitric oxide (NO) at nM concentrations performs multiple signaling roles that are essential for survival. These processes are regulated via the enzymes nNOS and eNOS, but another isoform, inducible nitric oxide synthase (iNOS) is capable of generating much higher concentrations (mM) over longer periods, resulting in the generation of very toxic species such as peroxynitrite. At high concentrations NO has many of the characteristics of an ideal anticancer molecule: it is cytotoxic (pro-apoptotic via peroxynitrite), it is a potent chemical radiosensitizer, it is anti-angiogenic and anti-metastatic. Thus, we see iNOS gene therapy as a strategy for targeting the generation of high concentrations of NO to tumours for therapeutic benefit. iNOS gene therapy should be used in combination with radiotherapy; so it is logical that the use of a radiation-inducible promoter should be part of the targeting strategy. We have tested several candidate promoters in vitro and in vivo. The WAF1 promoter has many of the properties desirable for therapeutic use including: rapid 3-4 fold induction at X-ray doses of 2 and 4Gy and no significant leakiness. WAF1 also has the advantage of being inducible by hypoxia and by the final product, NO. We have also tested the synthetic CArG promoter and demonstrated that, in addition to a high level of radiation inducibility, it is also inducible by NO. We have also been able to demonstrate potent radiosensitization (SER 2.0-2.5) in tumour cells in vitro and in vivo using iNOS gene transfer with constitutive or radiation-inducible promoters. We have also tested the use of iNOS gene therapy in combination with cisplatin and shown significant enhancement

  3. Endothelial nitric oxide synthase and superoxide mediate hemodynamic initiation of intracranial aneurysms.

    Directory of Open Access Journals (Sweden)

    Nicholas Liaw

    Full Text Available Hemodynamic insults at arterial bifurcations are believed to play a critical role in initiating intracranial aneurysms. Recent studies in a rabbit model indicate that aneurysmal damage initiates under specific wall shear stress conditions when smooth muscle cells (SMCs become pro-inflammatory and produce matrix metalloproteinases (MMPs. The mechanisms leading to SMC activation and MMP production during hemodynamic aneurysm initiation are unknown. The goal is to determine if nitric oxide and/or superoxide induce SMC changes, MMP production and aneurysmal remodeling following hemodynamic insult.Bilateral common carotid artery ligation was performed on rabbits (n = 19, plus 5 sham operations to induce aneurysmal damage at the basilar terminus. Ligated animals were treated with the nitric oxide synthase (NOS inhibitor LNAME (n = 7 or the superoxide scavenger TEMPOL (n = 5 and compared to untreated animals (n = 7. Aneurysm development was assessed histologically 5 days after ligation. Changes in NOS isoforms, peroxynitrite, reactive oxygen species (ROS, MMP-2, MMP-9, and smooth muscle α-actin were analyzed by immunohistochemistry.LNAME attenuated ligation-induced IEL loss, media thinning and bulge formation. In untreated animals, immunofluorescence showed increased endothelial NOS (eNOS after ligation, but no change in inducible or neuronal NOS. Furthermore, during aneurysm initiation ROS increased in the media, but not the intima, and there was no change in peroxynitrite. In LNAME-treated animals, ROS production did not change. Together, this suggests that eNOS is important for aneurysm initiation but not by producing superoxide. TEMPOL treatment reduced aneurysm development, indicating that the increased medial superoxide is also necessary for aneurysm initiation. LNAME and TEMPOL treatment in ligated animals restored α-actin and decreased MMPs, suggesting that eNOS and superoxide both lead to SMC de-differentiation and MMP production

  4. to view fulltext PDF

    Indian Academy of Sciences (India)

    PRAKASH

    superoxide generation, degranulation, and integrin expression by human neutrophils: novel antiinflammatory properties of nitric oxide-derived reactive species in vascular cells; Circ. Res. 91 375–381. Collins S 1987 The HL-60 promyelocytic leukemia cell line: proliferation, differentiation, and cellular oncogene expression;.

  5. Influence of nitric acid on the kinetic of complexation of uranyl nitrate extracted by TBP

    International Nuclear Information System (INIS)

    Pushlenkov, M.F.; Zimenkov, V.V.

    1982-02-01

    The effect of nitric acid on the solvatation rate of uranyl nitrate with tributyl phosphate is studied. In the process of mass transfer, it is shown that nitric acid enables the extraction of uranyl nitrate, therefore its concentration in the organic phase exceeds that in equilibrium solution. Subsequently uranyl nitrate ''displaces'' nitric acid. The presence of the acid in aqueous and organic phases affects in a complicated manner the rate of solvatation of uranyl nitrate with tributyl phosphate [fr

  6. Invasive Species

    Science.gov (United States)

    Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

  7. Nitric oxide, reactive nitrogen species and associated enzymes during plant senescence

    Czech Academy of Sciences Publication Activity Database

    Procházková, Dagmar; Wilhelmová, Naděžda

    2011-01-01

    Roč. 24, č. 2 (2011), s. 61-65 ISSN 1089-8603 R&D Projects: GA ČR(CZ) GAP501/11/1239 Institutional research plan: CEZ:AV0Z50380511 Keywords : Cytokinin * Ethylene * Nitrotyrosine Subject RIV: EF - Botanics Impact factor: 3.548, year: 2011

  8. Optimization of conditions to produce nitrous gases by electrochemical reduction of nitric acid

    International Nuclear Information System (INIS)

    Lemaire, M.; CEA Centre d'Etudes de la Vallee du Rhone, 30 -Marcoule

    1996-01-01

    Gaseous nitrogen oxides (NO and NO 2 ) involved as oxidizing agents in nuclear fuel reprocessing can be an produced by electrochemical reduction of nitric acid. This could be an interesting alternative to the usual process because no wastes are generated. Voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0.05 V S HE and 0.3 V S HE and O.5 V S HE and 1 V S HE. The highest potential region reduction mechanism was studies by: classical micro-electrolysis methods; macro-electrolysis methods; infra-red spectroscopy couplet to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric acid reduction can also be explained by an other chemical reaction. In the potential value of platinum electrode is above 0.8 V S HE, products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author)

  9. Optimization of the nitrous vapors experimental conditions production by nitric acid electrochemical reduction

    International Nuclear Information System (INIS)

    Lemaire, M.

    1996-01-01

    Gaseous nitrogen oxides (NO and NO 2 ) involved as oxidizing agents in nuclear fuel reprocessing can be produced by electrochemical reduction of nitric acid. This is an interesting alternative to the existing process because no wastes are generated. voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0,05 V SHE and between 0,5 V SHE and 1 V SHE . The highest potential region reduction mechanism was studied by: classical micro-electrolysis methods, macro-electrolysis methods, infrared spectroscopy coupled to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric reduction can also explained by an other chemical reaction. If the potential value of platinum electrode is above 0,8 V SHE , products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author)

  10. Safety in the Chemical Laboratory: Nitric Acid, Nitrates, and Nitro Compounds.

    Science.gov (United States)

    Bretherick, Leslie

    1989-01-01

    Discussed are the potential hazards associated with nitric acid, inorganic and organic nitrate salts, alkyl nitrates, acyl nitrates, aliphatic nitro compounds, aromatic nitro compounds, and nitration reactions. (CW)

  11. Nitric oxide antagonizes the acid tolerance response that protects Salmonella against innate gastric defenses.

    Directory of Open Access Journals (Sweden)

    Travis J Bourret

    2008-03-01

    Full Text Available Reactive nitrogen species (RNS derived from dietary and salivary inorganic nitrogen oxides foment innate host defenses associated with the acidity of the stomach. The mechanisms by which these reactive species exert antimicrobial activity in the gastric lumen are, however, poorly understood.The genetically tractable acid tolerance response (ATR that enables enteropathogens to survive harsh acidity was screened for signaling pathways responsive to RNS. The nitric oxide (NO donor spermine NONOate derepressed the Fur regulon that controls secondary lines of resistance against organic acids. Despite inducing a Fur-mediated adaptive response, acidified RNS largely repressed oral virulence as demonstrated by the fact that Salmonella bacteria exposed to NO donors during mildly acidic conditions were shed in low amounts in feces and exhibited ameliorated oral virulence. NO prevented Salmonella from mounting a de novo ATR, but was unable to suppress an already functional protective response, suggesting that RNS target regulatory cascades but not their effectors. Transcriptional and translational analyses revealed that the PhoPQ signaling cascade is a critical ATR target of NO in rapidly growing Salmonella. Inhibition of PhoPQ signaling appears to contribute to most of the NO-mediated abrogation of the ATR in log phase bacteria, because the augmented acid sensitivity of phoQ-deficient Salmonella was not further enhanced after RNS treatment.Since PhoPQ-regulated acid resistance is widespread in enteric pathogens, the RNS-mediated inhibition of the Salmonella ATR described herein may represent a common component of innate host defenses.

  12. Occurrence, structure, and evolution of nitric oxide synthase-like proteins in the plant kingdom.

    Science.gov (United States)

    Jeandroz, Sylvain; Wipf, Daniel; Stuehr, Dennis J; Lamattina, Lorenzo; Melkonian, Michael; Tian, Zhijian; Zhu, Ying; Carpenter, Eric J; Wong, Gane Ka-Shu; Wendehenne, David

    2016-03-01

    Nitric oxide (NO) signaling regulates various physiological processes in both animals and plants. In animals, NO synthesis is mainly catalyzed by NO synthase (NOS) enzymes. Although NOS-like activities that are sensitive to mammalian NOS inhibitors have been detected in plant extracts, few bona fide plant NOS enzymes have been identified. We searched the data set produced by the 1000 Plants (1KP) international consortium for the presence of transcripts encoding NOS-like proteins in over 1000 species of land plants and algae. We also searched for genes encoding NOS-like enzymes in 24 publicly available algal genomes. We identified no typical NOS sequences in 1087 sequenced transcriptomes of land plants. In contrast, we identified NOS-like sequences in 15 of the 265 algal species analyzed. Even if the presence of NOS enzymes assembled from multipolypeptides in plants cannot be conclusively discarded, the emerging data suggest that, instead of generating NO with evolutionarily conserved NOS enzymes, land plants have evolved finely regulated nitrate assimilation and reduction processes to synthesize NO through a mechanism different than that in animals. Copyright © 2016, American Association for the Advancement of Science.

  13. Nocardia iowensis sp. nov., an organism rich in biocatalytically important enzymes and nitric oxide synthase

    Science.gov (United States)

    Lamm, Andrew S.; Khare, Arshdeep; Conville, Patricia; Lau, Peter C. K.; Bergeron, Hélène; Rosazza, John P. N.

    2009-01-01

    Nocardia strain NRRL 5646, isolated from a garden soil sample in Osceola, Iowa, USA, was initially of interest as an antibiotic producer. It contained biocatalytically important enzymes and represented the first described nitric oxide synthase enzyme system in bacteria. The present polyphasic taxonomic study was undertaken to differentiate strain NRRL 5646T from related species of the genus Nocardia. Chemotaxonomic analyses included determinations of the fatty acid methyl ester profile (C16 : 1ω6c/C16 : 1ω7c, C16 : 0, C18 : 1ω9c and C18 : 0 10-methyl as major components), quinone [cyclo MK-8(H4) as the major component], polar lipid (diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside as major components) and mycolic acid. These results supported its placement within the genus Nocardia. Biochemical testing and 16S rRNA, 65-kDa heat-shock protein (hsp65) and preprotein translocase (secA1) gene sequence analyses differentiated strain NRRL 5646T from recognized Nocardia species. Previous studies have demonstrated that other genetic sequences (carboxylic acid reductase, Nocardia phosphopantetheinyl transferase and GTP cyclohydrolase I) from strain NRRL 5646T can also be used to substantiate its uniqueness. The level of 16S rRNA gene sequence similarity between strain NRRL 5646T and the type strains of Nocardia tenerifensis and Nocardia brasiliensis was 98.8 %. However, strain NRRL 5646T could be clearly distinguished from these Nocardia species based on DNA–DNA hybridization data. Consequently, strain NRRL 5646T is considered to represent a novel species of the genus Nocardia, for which the name Nocardia iowensis sp. nov. is proposed. The type strain is NRRL 5646T (=UI 122540T=NRRL B-24671T=DSM 45197T). PMID:19622667

  14. The role of nitric oxide in low level light therapy

    Science.gov (United States)

    Hamblin, Michael R.

    2008-02-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage by reducing cellular apoptosis has been known for almost forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. Firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of choosing amongst a large number of illumination parameters has led to the publication of a number of negative studies as well as many positive ones. This review will focus on the role of nitric oxide in the cellular and tissue effects of LLLT. Red and near-IR light is primarily absorbed by cytochrome c oxidase (unit four in the mitochondrial respiratory chain). Nitric oxide produced in the mitochondria can inhibit respiration by binding to cytochrome c oxidase and competitively displacing oxygen, especially in stressed or hypoxic cells. If light absorption displaced the nitric oxide and thus allowed the cytochrome c oxidase to recover and cellular respiration to resume, this would explain many of the observations made in LLLT. Why the effect is only seen in hypoxic, stressed or damaged cells or tissues? How the effects can keep working for some time (hours or days) postillumination? Why increased NO concentrations are sometimes measured in cell culture or in animals? How blood flow can be increased? Why angiogenesis is sometimes increased after LLLT in vivo?

  15. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  16. Application of nitric oxide measurements in clinical conditions beyond asthma.

    Science.gov (United States)

    Malinovschi, Andrei; Ludviksdottir, Dora; Tufvesson, Ellen; Rolla, Giovanni; Bjermer, Leif; Alving, Kjell; Diamant, Zuzana

    2015-01-01

    Fractional exhaled nitric oxide (FeNO) is a convenient, non-invasive method for the assessment of active, mainly Th2-driven, airway inflammation, which is sensitive to treatment with standard anti-inflammatory therapy. Consequently, FeNO serves as a valued tool to aid diagnosis and monitoring in several asthma phenotypes. More recently, FeNO has been evaluated in several other respiratory, infectious, and/or immunological conditions. In this short review, we provide an overview of several clinical studies and discuss the status of potential applications of NO measurements in clinical conditions beyond asthma.

  17. Redox chemistry of americium in nitric acid media

    International Nuclear Information System (INIS)

    Picart, S.; Jobelin, I.; Armengol, G.; Adnet, JM.

    2004-01-01

    The redox properties of the actinides are very important parameters for speciation studies and spent nuclear fuel reprocessing based on liquid-liquid extraction of actinides at different oxidation states (as in the Purex or Sesame process). They are also very useful for developing analytical tools including coulometry and redox titration. This study addressed the americium(IV)/americium(III) and americium(VI)/americium(V) redox couples, focusing on exhaustive acquisition of the thermodynamic and kinetic parameters of americium oxidation at an electrode in a complexing nitric acid medium. (authors)

  18. Hypoxia tolerance, nitric oxide, and nitrite: Lessons from extreme animals

    DEFF Research Database (Denmark)

    Fago, Angela; B. Jensen, Frank

    2015-01-01

    survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and – in air breathing animals - redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite...... nitrite. The aim of this review is to highlight recent work illustrating the widespread roles of NO and nitrite in the tolerance to extreme oxygen deprivation, in particular in the red-eared slider turtle and crucian carp, but also in diving marine mammals. The emerging picture underscores the importance...... of NO and nitrite signaling in the adaptive response to hypoxia in vertebrate animals....

  19. Generation of nitric oxide from nitrite by carbonic anhydrase

    DEFF Research Database (Denmark)

    Aamand, Rasmus; Dalsgaard, Thomas; Jensen, Frank B

    2009-01-01

    In catalyzing the reversible hydration of CO2 to bicarbonate and protons, the ubiquitous enzyme carbonic anhydrase (CA) plays a crucial role in CO2 transport, in acid-base balance, and in linking local acidosis to O2 unloading from hemoglobin. Considering the structural similarity between...... bicarbonate and nitrite, we hypothesized that CA uses nitrite as a substrate to produce the potent vasodilator nitric oxide (NO) to increase local blood flow to metabolically active tissues. Here we show that CA readily reacts with nitrite to generate NO, particularly at low pH, and that the NO produced...

  20. Nitric Oxide Manipulation: A Therapeutic Target for Peripheral Arterial Disease?

    Directory of Open Access Journals (Sweden)

    Gareth Williams

    2012-01-01

    Full Text Available Peripheral Arterial Disease (PAD is a cause of significant morbidity and mortality in the Western world. Risk factor modification and endovascular and surgical revascularisation are the main treatment options at present. However, a significant number of patients still require major amputation. There is evidence that nitric oxide (NO and its endogenous inhibitor asymmetric dimethylarginine (ADMA play significant roles in the pathophysiology of PAD. This paper reviews experimental work implicating the ADMA-DDAH-NO pathway in PAD, focussing on both the vascular dysfunction and effects within the ischaemic muscle, and examines the potential of manipulating this pathway as a novel adjunct therapy in PAD.

  1. Study of the solubility of molybdenum in nitric solutions

    International Nuclear Information System (INIS)

    Faugeras, P.; Lheureux, C.; Leroy, P.

    1961-01-01

    The use of U-Mo alloys in reactors poses naturally the problem of the chemical treatment of these nuclear fuels. The molybdenum is scarcely soluble in the nitric solutions used during this treatment, and may precipitate during these operations. In order to forestall these incidents, we have made a study of the solubility of molybdenum as a function of temperature, of the acidity, and of the uranium concentration. We have also studied the influence of the presence of ferric ions on this solubility. (author) [fr

  2. Fourier transform infrared studies of reduction of nitric oxide by ethylene over V[sub 2]O[sub 5] layered on ZrO[sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Takashi; Hatayama, Fumikazu (School of Allied Medical Sciences, Kobe University, Kobe (Japan)); Toda, Yoshio (Department of Industrial Chemistry, Osaka Prefectural Technical College, Osaka (Japan)); Konishi, Shoichiro; Miyata, Hisashi (Department of Applied Chemistry, University of Osaka Prefecture, Osaka (Japan))

    1994-12-31

    The reduction mechanism of nitric oxide by ethylene in the presence or absence of oxygen on mono- and multi-layer V[sub 2]O[sub 5]/ZrO[sub 2] and the structures of the catalysts under reaction conditions have been studied by Fourier transform infrared spectroscopy as well as by analysis of the reaction products. For the reaction of a mixture of NO+C[sub 2]H[sub 4], only carboxylate species were observed at higher temperatures, although at lower temperatures nitrate species were formed. No bands due to a complex of NO+C[sub 2]H[sub 4] were observed. From the results, it is proposed that ethylene is oxidized by the catalyst to form carbon dioxide via carbonyl and carboxylate species and nitric oxide reoxidizes the catalyst to form nitrogen. The quantitative analysis of the V=O band in the region of 1100-900 cm[sup -1] by band shape analysis indicates that only the surface V=O species in the top layer of the catalyst interacts with the adsorbed species

  3. Vasodilatory effect of asafoetida essential oil on rat aorta rings: The role of nitric oxide, prostacyclin, and calcium channels.

    Science.gov (United States)

    Esmaeili, Hassan; Sharifi, Mozhdeh; Esmailidehaj, Mansour; Rezvani, Mohammad Ebrahim; Hafizibarjin, Zeynab

    2017-12-01

    Asafoetida is an oleo-gum resin mainly obtained from Ferula assa-foetida L. species in the apiaceae family. Previous studies have shown that it has antispasmodic effects on rat's and pig's ileums. The main goals of this study were to assess the vasodilatory effect of asafoetida essential oil (AEO) on the contractile response of rat's aorta rings and to find the role of nitric oxide, cyclooxygenase, and calcium channels. Thoracic aorta rings were stretched under a steady-state tension of 1 g in an organ bath apparatus for 1 h and then precontracted by KCl (80 mM) in the presence and absence of AEO. L-NAME (blocker of nitric oxide synthase) and indomethacin (blocker of cyclooxygenase) were used to assess the role of nitric oxide (NO) and prostacyclin in the vasodilatory effect of AEO. Also, the effect of AEO on the influx of calcium through the cell membrane calcium channels was determined. Data showed that AEO had vasodilatory effects on aorta rings with both intact (IC 50  = 1.6 µl/l) or denuded endothelium (IC 50  = 19.2 µl/l) with a significantly higher potency in intact endothelium rings. The vasodilatory effects of AEO were reduced, but not completely inhibited, in the presence of L-NAME or indomethacin. Adding AEO to the free-calcium medium also significantly reduced the CaCl 2 -induced contractions. The results indicated that AEO has a potent vasodilatory effect that is endothelium-dependent and endothelium-independent. Also, it reduced the influx of calcium into the cell through plasma membrane calcium channels. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. Role of Nitric Oxide in the Regulation of Renin and Vasopressin Secretion

    Science.gov (United States)

    Reid, Ian A.

    1994-01-01

    Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, immune, and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, and anterior pituitary gland, and evidence is accumulating that it contributes to the regulation of the secretion of renin and vasopressin, hormones that play key roles in the control of sodium and water balance. Several lines of evidence have implicated nitric oxide in the control of renin secretion. The enzyme nitric oxide synthase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa, a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro, suggesting a stimulatory role for the L-arginine/nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa, and beta adrenoceptor mechanisms that regulate renin secretion. Histochemical and immunocytochemical studies have revealed the presence of nitric oxide synthase in the supraoptic and paraventricular nuclei of the hypothalamus and in the posterior pituitary gland. Colocalization of nitric oxide synthase and vasopressin has been demonstrated in some hypothalamic neurons. Nitric oxide synthase activity in the hypothalamus and pituitary is increased by maneuvers known to stimulate vasopressin secretion, including salt loading and dehydration, Administration of L-arginine and nitric

  5. Production of medically useful nitric monoxide using AC arc discharge.

    Science.gov (United States)

    Li, S R; Huang, Y F; Liu, Z; Sui, M H; Liu, J M; Yan, K P

    2018-02-28

    Inhaled nitric monoxide (iNO) is increasingly used as a medical treatment for acute respiratory distress syndrome. A course of the existing nitric monoxide (NO) therapy with gas cylinders could cost up to approximately $15,000 for an average of 30.2 h. Moreover, a gas cylinder containing a mixture of N 2 and NO may potentially leak NO. The objective of this study is to develop an efficient and cost-effective on-site iNO generation system. In the present setup, NO was generated by using dry air or mixed oxygen/nitrogen (O 2 /N 2 ) and an AC power source with an output power level of 5-30 W at atmospheric pressure. The simultaneously produced NO 2 was eliminated with an ammonium sulfite ((NH 4 ) 2 SO 3 ) solution. The effects of the O 2 /N 2 ratio, gas flow rate, discharge gap distance, output energy density and electrode structure on NO x concentration and the NO/NO 2 ratio are reported. The concentrations of NO and NO 2 reached 62 ppm and 3 ppm, respectively, after absorption and dilution at a gas flow rate of 6 L/min. With the present setup, the AC arc discharge produced NO x at a stable concentration for at least 6 h using dry air. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Use of extractive distillation to produce concentrated nitric acid

    International Nuclear Information System (INIS)

    Campbell, P.C.; Griffin, T.P.; Irwin, C.F.

    1981-04-01

    Concentrated nitric acid (> 95 wt %) is needed for the treatment of off-gases from a fuels-reprocessing plant. The production of concentrated nitric acid by means of extractive distillation in the two-pot apparatus was studied to determine the steady-state behavior of the system. Four parameters, EDP volume (V/sub EDP/) and temperature (T/sub EDP/), acid feed rate, and solvent recycle, were independently varied. The major response factors were percent recovery (CPRR) and product purity (CCP). Stage efficiencies also provided information about the system response. Correlations developed for the response parameters are: CPRR = 0.02(V/sub EDP/ - 800 cc) + 53.5; CCP = -0.87 (T/sub EDP/ - 140 0 C) + 81; eta/sub V,EDP/ = 9.1(F/sub feed/ - 11.5 cc/min) - 0.047(V/sub EDP/ - 800 cc) - 2.8(F/sub Mg(NO 3 ) 2 / - 50 cc/min) + 390; and eta/sub L,EDP/ = 1.9(T/sub EDP/ - 140 0 C) + 79. A computer simulation of the process capable of predicting steady-state conditions was developed, but it requires further work

  7. Exhaled nitric oxide in diagnosis and management of respiratory diseases.

    Science.gov (United States)

    Abba, Abdullah A

    2009-10-01

    The analysis of biomarkers in exhaled breath constituents has recently become of great interest in the diagnosis, treatment and monitoring of many respiratory conditions. Of particular interest is the measurement of fractional exhaled nitric oxide (FENO) in breath. Its measurement is noninvasive, easy and reproducible. The technique has recently been standardized by both American Thoracic Society and European Respiratory Society. The availability of cheap, portable and reliable equipment has made the assay possible in clinics by general physicians and, in the near future, at home by patients. The concentration of exhaled nitric oxide is markedly elevated in bronchial asthma and is positively related to the degree of esinophilic inflammation. Its measurement can be used in the diagnosis of bronchial asthma and titration of dose of steroids as well as to identify steroid responsive patients in chronic obstructive pulmonary disease. In primary ciliary dyskinesia, nasal NO is diagnostically low and of considerable value in diagnosis. Among lung transplant recipients, FENO can be of great value in the early detection of infection, bronchioloitis obliterans syndrome and rejection. This review discusses the biology, factors affecting measurement, and clinical application of FENO in the diagnosis and management of respiratory diseases.

  8. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Beg Mohammed

    2009-01-01

    Full Text Available Study Objective : The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD and compare it with the results in patients with asthma and a control population. Design : Cross-sectional study. Materials and Methods : Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naοve asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. Results : All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54±28.01 vs 22.00±6.69; P =0.0001 but lower than the subjects with asthma (56.54±28.01 vs 84.78±39.32 P = 0.0285.The FENO values in COPD subjects were inversely related to the FEV 1 /FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. Conclusion : There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects.

  9. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    Science.gov (United States)

    Beg, Mohammed F. S.; Alzoghaibi, Mohammad A.; Abba, Abdullah A.; Habib, Syed S.

    2009-01-01

    STUDY OBJECTIVE: The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO) is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD) and compare it with the results in patients with asthma and a control population. DESIGN: Cross-sectional study. MATERIALS AND METHODS: Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naïve asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. RESULTS: All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54±28.01 vs 22.00±6.69; P=0.0001) but lower than the subjects with asthma (56.54±28.01 vs 84.78±39.32 P=0.0285).The FENO values in COPD subjects were inversely related to the FEV1/FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. CONCLUSION: There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects. PMID:19561927

  10. Nitric-phosphoric acid oxidation of organic waste materials

    International Nuclear Information System (INIS)

    Pierce, R.A.; Smith, J.R.

    1995-01-01

    A wet chemical oxidation technology has been developed to address issues facing defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate a heterogenous mixture of radioactive-contaminated solid waste, the technology can also remediate other hazardous waste forms. The process, unique to Savannah River, offers a valuable alternative to incineration and other high-temperature or high-pressure oxidation processes. The process uses nitric acid in phosphoric acid; phosphoric acid allows nitric acid to be retained in solution well above its normal boiling point. The reaction converts organics to carbon dioxide and water, and generates NO x vapors which can be recycled using air and water. Oxidation is complete in one to three hours. In previous studies, many organic compounds were completely oxidized, within experimental error, at atmospheric pressure below 180 degrees C; more stable compounds were decomposed at 200 degrees C and 170 kPa. Recent studies have evaluated processing parameters and potential throughputs for three primary compounds: EDTA, polyethylene, and cellulose. The study of polyvinylchloride oxidation is incomplete at this time

  11. Exhaled nitric oxide in diagnosis and management of respiratory diseases

    Directory of Open Access Journals (Sweden)

    Abba Abdullah

    2009-01-01

    Full Text Available The analysis of biomarkers in exhaled breath constituents has recently become of great interest in the diagnosis, treatment and monitoring of many respiratory conditions. Of particular interest is the measurement of fractional exhaled nitric oxide (FENO in breath. Its measurement is noninvasive, easy and reproducible. The technique has recently been standardized by both American Thoracic Society and European Respiratory Society. The availability of cheap, portable and reliable equipment has made the assay possible in clinics by general physicians and, in the near future, at home by patients. The concentration of exhaled nitric oxide is markedly elevated in bronchial asthma and is positively related to the degree of esinophilic inflammation. Its measurement can be used in the diagnosis of bronchial asthma and titration of dose of steroids as well as to identify steroid responsive patients in chronic obstructive pulmonary disease. In primary ciliary dyskinesia, nasal NO is diagnostically low and of considerable value in diagnosis. Among lung transplant recipients, FENO can be of great value in the early detection of infection, bronchioloitis obliterans syndrome and rejection. This review discusses the biology, factors affecting measurement, and clinical application of FENO in the diagnosis and management of respiratory diseases.

  12. Nitric Oxide-Mediated Posttranslational Modifications: Impacts at the Synapse

    Directory of Open Access Journals (Sweden)

    Sophie A. Bradley

    2016-01-01

    Full Text Available Nitric oxide (NO is an important gasotransmitter molecule that is involved in numerous physiological processes throughout the nervous system. In addition to its involvement in physiological plasticity processes (long-term potentiation, LTP; long-term depression, LTD which can include NMDAR-mediated calcium-dependent activation of neuronal nitric oxide synthase (nNOS, new insights into physiological and pathological consequences of nitrergic signalling have recently emerged. In addition to the canonical cGMP-mediated signalling, NO is also implicated in numerous pathways involving posttranslational modifications. In this review we discuss the multiple effects of S-nitrosylation and 3-nitrotyrosination on proteins with potential modulation of function but limit the analyses to signalling involved in synaptic transmission and vesicular release. Here, crucial proteins which mediate synaptic transmission can undergo posttranslational modifications with either pre- or postsynaptic origin. During normal brain function, both pathways serve as important cellular signalling cascades that modulate a diverse array of physiological processes, including synaptic plasticity, transcriptional activity, and neuronal survival. In contrast, evidence suggests that aging and disease can induce nitrosative stress via excessive NO production. Consequently, uncontrolled S-nitrosylation/3-nitrotyrosination can occur and represent pathological features that contribute to the onset and progression of various neurodegenerative diseases, including Parkinson’s, Alzheimer’s, and Huntington’s.

  13. Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

    Directory of Open Access Journals (Sweden)

    Kao Ming-Ching

    2011-02-01

    Full Text Available Abstract Background Hyperbaric oxygen therapy (HBOT is a known adjuvant for treating ischemia-related inner ear diseases. Controversies still exist in the role of HBOT in cochlear diseases. Few studies to date have investigated the cellular changes that occur in inner ears after HBOT. Nitric oxide, which is synthesized by nitric oxide synthase (NOS, is an important signaling molecule in cochlear physiology and pathology. Here we investigated the effects of hyperbaric oxygen on eardrum morphology, cochlear function and expression of NOS isoforms in cochlear substructures after repetitive HBOT in guinea pigs. Results Minor changes in the eardrum were observed after repetitive HBOT, which did not result in a significant hearing threshold shift by tone burst auditory brainstem responses. A differential effect of HBOT on the expression of NOS isoforms was identified. Upregulation of constitutive NOS (nNOS and eNOS was found in the substructures of the cochlea after HBOT, but inducible NOS was not found in normal or HBOT animals, as shown by immunohistochemistry. There was no obvious DNA fragmentation present in this HBOT animal model. Conclusions The present evidence indicates that the customary HBOT protocol may increase constitutive NOS expression but such upregulation did not cause cell death in the treated cochlea. The cochlear morphology and auditory function are consequently not changed through the protocol.

  14. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Beg Mohammed F S; Alzoghaibi, Mohammad A; Habib, Syed S; Abba, Abdullah A

    2009-01-01

    The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO) is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD) and compare it with the results in patients with asthma and a control population. Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naive asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54+ - 28.01 vs 22.00 + -6.69; P =0.0001) but lower than the subjects with asthma (56.54+ - 28.01 vs 84.78+ - 39.32 P 0.0285). The FENO values in COPD subjects were inversely related to the FEV 1 /FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects. (author)

  15. Nitric oxide heme interactions in nitrophorin from Cimex lectularius

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, R.; Auerbach, H., E-mail: auerbach@physik.uni-kl.de [University of Kaiserslautern, Department of Physics (Germany); Berry, R. E.; Walker, F. A. [The University of Arizona, Department of Chemistry and Biochemistry (United States); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)

    2016-12-15

    The nitrophorin from the bedbug Cimex lectularius (cNP) is a nitric oxide (NO) carrying protein. Like the nitrophorins (rNPs) from the kissing bug Rhodnius prolixus, cNP forms a stable heme Fe(III)-NO complex, where the NO can be stored reversibly for a long period of time. In both cases, the NPs are found in the salivary glands of blood-sucking bugs. The insects use the nitrophorins to transport the NO to the victim’s tissues, resulting in vasodilation and reduced blood coagulation. However, the structure of cNP is significantly different to those of the rNPs from Rhodnius prolixus. Furthermore, the cNP can bind a second NO molecule to the proximal heme cysteine when present at higher concentrations. High field Mössbauer spectroscopy on {sup 57}Fe enriched cNP complexed with NO shows reduction of the heme iron and formation of a ferrous nitric oxide (Fe(II)-NO) complex. Density functional theory calculations reproduce the experimental Mössbauer parameters and confirm this observation.

  16. Fractional exhaled nitric oxide-measuring devices: technology update

    Directory of Open Access Journals (Sweden)

    Maniscalco M

    2016-06-01

    Full Text Available Mauro Maniscalco,1 Carolina Vitale,2 Alessandro Vatrella,2 Antonio Molino,3 Andrea Bianco,4 Gennaro Mazzarella4 1Unit of Respiratory Diseases, Hospital “S Maria della Pietà” of Casoria, Naples, 2Unit of Respiratory Medicine, Department of Medicine and Surgery, University of Salerno, Salerno, 3Department of Respiratory Medicine, University Federico II, 4Department of Cardiothoracic and Respiratory Sciences, Second, University of Naples, Naples, Italy Abstract: The measurement of exhaled nitric oxide (NO has been employed in the diagnosis of specific types of airway inflammation, guiding treatment monitoring by predicting and assessing response to anti-inflammatory therapy and monitoring for compliance and detecting relapse. Various techniques are currently used to analyze exhaled NO concentrations under a range of conditions for both health and disease. These include chemiluminescence and electrochemical sensor devices. The cost effectiveness and ability to achieve adequate flexibility in sensitivity and selectivity of NO measurement for these methods are evaluated alongside the potential for use of laser-based technology. This review explores the technologies involved in the measurement of exhaled NO. Keywords: asthma, inflammation, nasal nitric oxide

  17. Environmental Effects on Fractional Exhaled Nitric Oxide in Allergic Children

    Directory of Open Access Journals (Sweden)

    Stefania La Grutta

    2012-01-01

    Full Text Available Fractional exhaled nitric oxide (FeNO is a non-invasive marker of airway inflammation in asthma and respiratory allergy. Environmental factors, especially indoor and outdoor air quality, may play an important role in triggering acute exacerbations of respiratory symptoms. The authors have reviewed the literature reporting effects of outdoor and indoor pollutants on FeNO in children. Although the findings are not consistent, urban and industrial pollution—mainly particles (PM2.5 and PM10, nitrogen dioxide (NO2, and sulfur dioxide (SO2—as well as formaldehyde and electric baseboard heating have been shown to increase FeNO, whilst ozone (O3 tends to decrease it. Among children exposed to Environmental Tobacco Smoke (ETS with a genetic polymorphisms in nitric oxide synthase genes (NOS, a higher nicotine exposure was associated with lower FeNO levels. Finally, although more studies are needed in order to better investigate the effect of gene and environment interactions which may affect the interpretation of FeNO values in the management of children with asthma, clinicians are recommended to consider environmental exposures when taking medical histories for asthma and respiratory allergy. Further research is also needed to assess the effects of remedial interventions aimed at reducing/abating environmental exposures in asthmatic/allergic patients.

  18. Nitric oxide in guard cells as an important secondary messenger during stomatal closure

    Directory of Open Access Journals (Sweden)

    Gunja eGayatri

    2013-10-01

    Full Text Available he modulation of guard cell function is the basis of stomatal closure, essential for optimizing water use and CO2 uptake by leaves. Nitric oxide (NO in guard cells plays a very important role as a secondary messenger during stomatal closure induced by effectors, including hormones. For example, exposure to abscisic acid (ABA triggers a marked increase in NO of guard cells, well before stomatal closure. In guard cells of multiple species, like Arabidopsis, Vicia and pea, exposure to ABA or methyl jasmonate or even microbial elicitors (e.g. chitosan induces production of NO as well as reactive oxygen species (ROS. The role of NO in stomatal closure has been confirmed by using NO donors (e.g. SNP and NO scavengers (like cPTIO and inhibitors of NOS (L-NAME or NR (tungstate. Two enzymes: a L-NAME-sensitive, nitric oxide synthase (NOS-like enzyme and a tungstate-sensitive nitrate reductase (NR, can mediate ABA-induced NO rise in guard cells. However, the existence of true NOS in plant tissues and its role in guard cell NO-production are still a matter of intense debate. Guard cell signal transduction leading to stomatal closure involves the participation of several components, besides NO, such as cytosolic pH, ROS, free Ca2+ and phospholipids. Use of fluorescent dyes has revealed that the rise in NO of guard cells occurs after the increase in cytoplasmic pH and ROS. The rise in NO causes an elevation in cytosolic free Ca2+ and promotes the efflux of cations as well as anions from guard cells. Stomatal guard cells have become a model system to study the signalling cascade mechanisms in plants, particularly with NO as a dominant component. The interrelationships and interactions of NO with cytosolic pH, ROS, and free Ca2+ are quite complex and need further detailed examination. While assessing critically the available literature, the present review projects possible areas of further work related to NO-action in stomatal guard cells.

  19. Differential effects of nitric oxide synthase inhibitors on endotoxin-induced liver damage in rats

    NARCIS (Netherlands)

    Vos, TA; Gouw, ASH; Klok, PA; Havinga, R; vanGoor, H; Roelofsen, H; Kuipers, F; Jansen, PLM; Moshage, H

    1997-01-01

    Background & Aims: During endotoxemia, expression of inducible nitric oxide synthase (iNOS) and nitric oxide production in the liver is increased, NO has been suggested to have a hepatoprotective function. The aim of this study was to investigate the distribution of iNOS and the effect of different

  20. Analysis of Steam Heating of a Two-Layer TBP/N-Paraffin/Nitric Acid Mixtures

    International Nuclear Information System (INIS)

    Laurinat, J.E.; Hassan, N.M.; Rudisill, T.S.; Askew, N.M.

    1998-01-01

    This report presents an analysis of steam heating of a two-layer tri-n-butyl phosphate (TBP)/n-paraffin-nitric acid mixture.The purpose of this study is to determine if the degree of mixing provided by the steam jet or by bubbles generated by the TBP/nitric acid reaction is sufficient to prevent a runaway reaction

  1. Mercury-free dissolution of aluminum-clad fuel in nitric acid

    Science.gov (United States)

    Christian, Jerry D.; Anderson, Philip A.

    1994-01-01

    A mercury-free dissolution process for aluminum involves placing the aluminum in a dissolver vessel in contact with nitric acid-fluoboric acid mixture at an elevated temperature. By maintaining a continuous flow of the acid mixture through the dissolver vessel, an effluent containing aluminum nitrate, nitric acid, fluoboric acid and other dissolved components are removed.

  2. Role of nitric oxide in glucose-, fructose and galactose-induced ...

    African Journals Online (AJOL)

    Previous studies have shown that the infusion of glucose, fructose and galactose resulted in significant increases in intestinal glucose uptake (IGU) and the role of nitric oxide in these responses was not known. The present study was designed to investigate the role of nitric oxide in the observed increases in IGU.

  3. Expression of inducible nitric oxide synthase in trigeminal ganglion cells during culture

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Zhou, MingFang; Zinck, Tina Jovanovic

    2005-01-01

    Nitric oxide (NO) is an important signalling molecule that has been suggested to be a key molecule for induction and maintenance of migraine attacks based on clinical studies, animal experimental studies and the expression of nitric oxide synthase (NOS) immunoreactivity within the trigeminovascular...

  4. Extraction of uranium (VI) from nitric acid with N-decanoyl pyrrolidine (DPOD) in toluene

    International Nuclear Information System (INIS)

    Han Jingtian; Sun Guoxin; Bao Borong

    1999-01-01

    The extraction behaviors of uranium (VI) from nitric acid by N-decanoyl pyrrolidine (DPOD) in toluene has been studied at varying concentrations of nitric acid, extractant, salting-out agent LiNO 3 and at different temperatures. The mechanism of extraction is discussed in the light of the results obtained

  5. Transportation impact analysis for the shipment of low specific activity nitric acid. Revisison 1

    International Nuclear Information System (INIS)

    Green, J.R.

    1995-01-01

    This is in support of the Plutonium-Uranium Extraction (PUREX) Facility Low Specific Activity (LSA) Nitric Acid Shipment Environmental Assessment. It analyzes potential toxicological and radiological risks associated with transportation of PUREX Facility LSA Nitric Acid from the Hanford Site to Portsmouth VA, Baltimore MD, and Port Elizabeth NJ

  6. Lack of endothelial nitric oxide synthase aggravates murine accelerated anti-glomerular basement membrane glomerulonephritis

    NARCIS (Netherlands)

    Heeringa, P; van Goor, H; Itoh-Lindstrom, Y; Maeda, N; Falk, RJ; Assmann, KJM; Kallenberg, CGM; Jennette, JC

    Nitric oxide (NO) radicals generated by endothelial nitric oxide synthase (eNOS) are involved in the regulation of vascular tone. In addition, NO radicals derived from eNOS inhibit platelet aggregation and leukocyte adhesion to the endothelium and, thus, may have anti-inflammatory effects. To study

  7. Expression of inducible nitric oxide synthase in trigeminal ganglion cells during culture

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Zhou, MingFang; Zinck, Tina Jovanovic

    2005-01-01

    Nitric oxide (NO) is an important signalling molecule that has been suggested to be a key molecule for induction and maintenance of migraine attacks based on clinical studies, animal experimental studies and the expression of nitric oxide synthase (NOS) immunoreactivity within the trigeminovascul...

  8. Modulation of cholinergic airway reactivity and nitric oxide production by endogenous arginase activity

    NARCIS (Netherlands)

    Meurs, Herman; Hamer, M.A M; Pethe, S; Vadon-Le Goff, S; Boucher, J.-L; Zaagsma, Hans

    1 Cholinergic airway constriction is functionally antagonized by agonist-induced constitutive nitric oxide synthase (cNOS)-derived nitric oxide (NO). Since cNOS and arginase, which hydrolyzes L-arginine to L-ornithine and urea, use L-arginine as a common substrate, competition between both enzymes

  9. Analysis of Steam Heating of a Two-Layer TBP/N-Paraffin/Nitric Acid Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.E. [Westinghouse Savannah River Company, AIKEN, SC (United States); Hassan, N.M.; Rudisill, T.S.; Askew, N.M.

    1998-07-22

    This report presents an analysis of steam heating of a two-layer tri-n-butyl phosphate (TBP)/n-paraffin-nitric acid mixture.The purpose of this study is to determine if the degree of mixing provided by the steam jet or by bubbles generated by the TBP/nitric acid reaction is sufficient to prevent a runaway reaction.

  10. Nitric oxide fumigation for control of bulb mites on flower bulbs and tubers

    Science.gov (United States)

    Nitric oxide fumigation was studied for efficacy to control bulb mites in the genus Rhizoglyphus and effects on germination and growth of flower bulbs and tubers. Bulb mites on infested peanuts were fumigated with nitric oxide at different concentrations under ultralow oxygen conditions in 1.9L jar...

  11. Sludge batch 9 follow-on actual-waste testing for the nitric-glycolic flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-03-23

    An actual-waste Sludge Batch 9 qualification run with the nitric-glycolic flowsheet (SC-18) was performed in FY16. In order to supplement the knowledge base for the nitric-glycolic flowsheet, additional testing was performed on the product slurries, condensates, and intermediate samples from run SC-18.

  12. Contribution of nitric oxide synthase from coagulase-negative staphylococci to the development of red myoglobin derivatives.

    Science.gov (United States)

    Ras, Geoffrey; Bailly, Xavier; Chacornac, Jean-Paul; Zuliani, Véronique; Derkx, Patrick; Seibert, Tim M; Talon, Régine; Leroy, Sabine

    2018-02-02

    As part of the microbial community of meat or as starter cultures, coagulase-negative staphylococci (CNS) serve several essential technological purposes in meat products, such as color development through the reduction of nitrate to nitrite. As the safety of nitrite as an additive has been questioned, we explored the potential of CNS to develop red myoglobin derivatives such as oxymyoglobin and nitrosomyoglobin. Nitrosoheme was extracted to evaluate NO production. This production could be due to a nitric oxide synthase (NOS) activity. In all CNS strains, a nos gene was identified. The NOS sequences deduced were highly conserved within CNS. A phylogenetic tree based on the NOS sequences revealed that the strains within species were clustered. Ninety-one percent of the strains, whatever the species, were able to form red myoglobin derivatives in aerobic conditions, but a high variability was observed between strains within species. However, NO production was low as nitrosomyoglobin represented 8% to 16% of the red pigments according to the species. Formation of oxymyoglobin, especially under aerobic conditions, was substantial, but varied greatly within species. The mechanism involved in the formation of oxymyoglobin could rely on staphylococcal reductases and remains to be explored. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. A study on electrochemical redox behavior of nitric acid by using a glassy carbon fiber column electrode system

    International Nuclear Information System (INIS)

    Kim, K. W.; Song, K. C.; Lee, I. H.; Choi, I. K.; You, J. H.

    1999-01-01

    Electrochemical redox behaviors of nitric acid were studied by using a glassy carbon fiber column electrode system, and its reaction mechanism was analyzed in several ways. The electrochemical reaction in less than 2.0 M nitric acid was not observed, but in more than 2.0 M nitric acid, the reduction rate of nitric acid to produce nitrous acid was slow so that the nitric acid solution had to be contacted with electrode enough in order for a apparent reduction current of nitric acid to nitrous acid be to observed. The nitrous acid generated in more than 2.0 M nitric acid was rapidly and easily reduced to NOx through an autocatalytic reaction. Sulfamic acid was confirmed to be effective to destroy the nitrous acid. The sulfamic acid of at least 0.05M was necessary to remove the nitrous acid generated in 3.5 M nitric acid

  14. Influences of the heme-lysine crosslink in cytochrome P460 over redox catalysis and nitric oxide sensitivity.

    Science.gov (United States)

    Vilbert, Avery C; Caranto, Jonathan D; Lancaster, Kyle M

    2018-01-14

    Ammonia (NH 3 )-oxidizing bacteria (AOB) derive total energy for life from the multi-electron oxidation of NH 3 to nitrite (NO 2 - ). One obligate intermediate of this metabolism is hydroxylamine (NH 2 OH), which can be oxidized to the potent greenhouse agent nitrous oxide (N 2 O) by the AOB enzyme cytochrome (cyt) P460. We have now spectroscopically characterized a 6-coordinate (6c) {FeNO} 7 intermediate on the NH 2 OH oxidation pathway of cyt P460. This species has two fates: it can either be oxidized to the {FeNO} 6 that then undergoes attack by NH 2 OH to ultimately generate N 2 O, or it can lose its axial His ligand, thus generating a stable, off-pathway 5-coordinate (5c) {FeNO} 7 species. We show that the wild type (WT) cyt P460 exhibits a slow nitric oxide (NO)-independent conversion ( k His-off = 2.90 × 10 -3 s -1 ), whereas a cross-link-deficient Lys70Tyr cyt P460 mutant protein underwent His dissociation via both a NO-independent ( k His-off = 3.8 × 10 -4 s -1 ) and a NO-dependent pathway [ k His-off(NO) = 790 M -1 s -1 ]. Eyring analyses of the NO-independent pathways for these two proteins revealed a significantly larger ( ca. 27 cal mol -1 K -1 ) activation entropy (Δ S ‡ ) in the cross-link-deficient mutant. Our results suggest that the Lys-heme cross-link confers rigidity to the positioning of the heme P460 cofactor to avoid the fast NO-dependent His dissociation pathway and subsequent formation of the off-pathway 5c {FeNO} 7 species. The relevance of these findings to NO signaling proteins such as heme-nitric oxide/oxygen binding (H-NOX) is also discussed.

  15. Nitrite to nitric oxide interconversion by heme FeII complex assisted by [CuI(tmpa)]+

    KAUST Repository

    Turias, Francesc

    2015-09-09

    The present computational study complements the recent experimental efforts by Karlin and coworkers to describe the interconversion of nitrite to nitric oxide by means of an iron porphyrin complex together with a Cu chemical system, i.e., the iron(II) complex (F8TPP)FeII [F8TPP = tetrakis(2,6-difluorophenyl)porphyrinate(2−)] and a preformed copper(II)–nitrito complex [(tmpa)CuII(NO2)][B(C6F5)4] [tmpa = tris(2-pyridylmethyl)amine], being the latter an oxidized species of [(tmpa)CuI(MeCN)]+. By DFT calculations, we unravel how the reduction of nitrite to nitric oxide takes place through a μ-oxo heme-FeIII–O–CuII complex, following a mimetic path as in the cytochrome c oxidase. Mayer bond order (MBO) and energy decomposition analyses are used to analyze the bonding strength of such nitro derivatives to either copper or iron. © 2015 Springer Science+Business Media New York

  16. L-Arginine Increases Cytotoxicity in Irradiated Ehrlich Carcinoma Cell Line: Possible Potential Role of Nitric Oxide

    International Nuclear Information System (INIS)

    Noaman, E.

    2008-01-01

    Cancer cells possess nitric oxide syntheses (NOS) which metabolize L-Arginine (L-Arg) for producing nitric oxide (NO) The present study investigates the relations between NO and ionizing radiation in the Ehrlich ascites carcinoma (EAC) cell line. NOS activity was stimulated by exposure of cells to L-Arg just after irradiation. L-Arg (5 m M) supply led to an increase in ionizing radiation induced cytotoxicity (% of viability 18± 3 %) whereas, neither L-Arg itself nor ionizing irradiation caused cell death at the doses used in this study. Also, cells were treated either with L-Thio citrulline (L-Thio), an irreversible inhibitor of NOS or with exogenous superoxide dismutase (SOD) and catalase. L-Thio and SOD prevented L-Arg mediated deleterious effects on Irradiated cells, whereas catalase was ineffective. Intracellular antioxidant enzyme activity was also determined. Ionizing radiation + L-Arg stress altered the activity of catalase (66 % decrease) and glutathione peroxidase (83 % decrease). Our findings demonstrated that L-Arg induces increase the radiation-mediated deleterious effects in Ehrlich ascites carcinoma cells cytotoxicity and that the ratio NO/ O 2 plays a key role in these processes. NO could participate the deleterious effect of irradiation, in conjugation with others reactive oxygen species (ROS) produced during the oxidation of intracellular components by ionizing radiation (dose 6 Gy)

  17. The Base Excision Repair system of Salmonella enterica serovar typhimurium counteracts DNA damage by host nitric oxide.

    Directory of Open Access Journals (Sweden)

    Anthony R Richardson

    2009-05-01

    Full Text Available Intracellular pathogens must withstand nitric oxide (NO. generated by host phagocytes. Salmonella enterica serovar Typhimurium interferes with intracellular trafficking of inducible nitric oxide synthase (iNOS and possesses multiple systems to detoxify NO.. Consequently, the level of NO. stress encountered by S. Typhimurium during infection in vivo has been unknown. The Base Excision Repair (BER system recognizes and repairs damaged DNA bases including cytosine and guanine residues modified by reactive nitrogen species. Apurinic/apyrimidinic (AP sites generated by BER glycosylases require subsequent processing by AP endonucleases. S. Typhimurium xth nfo mutants lacking AP endonuclease activity exhibit increased NO. sensitivity resulting from chromosomal fragmentation at unprocessed AP sites. BER mutant strains were thus used to probe the nature and extent of nitrosative damage sustained by intracellular bacteria during infection. Here we show that an xth nfo S. Typhimurium mutant is attenuated for virulence in C3H/HeN mice, and virulence can be completely restored by the iNOS inhibitor L-NIL. Inactivation of the ung or fpg glycosylase genes partially restores virulence to xth nfo mutant S. Typhimurium, demonstrating that NO. fluxes in vivo are sufficient to modify cytosine and guanine bases, respectively. Mutants lacking ung or fpg exhibit NO.-dependent hypermutability during infection, underscoring the importance of BER in protecting Salmonella from the genotoxic effects of host NO.. These observations demonstrate that host-derived NO. damages Salmonella DNA in vivo, and the BER system is required to maintain bacterial genomic integrity.

  18. Comparison the effects of nitric oxide and spermidin pretreatment on alleviation of salt stress in chamomile plant (Matricaria recutita L.

    Directory of Open Access Journals (Sweden)

    Fazelian Nasrin

    2012-08-01

    Full Text Available Salt stress is an important environmental stress that produces reactive oxygen species in plants and causes oxidative injuries. In this investigation, salt stress reduced the shoot and root length, while increased the content of malondealdehyde, Hydrogen peroxide, and the activity of Ascorbate peroxidase andguaiacol peroxidase. Pretreatment of chamomile plants under salt stress with sodium nitroprussideand Spermidin caused enhancement of growth parameters and reduction of malondealdehyde and Hydrogen peroxide content. Pretreatment of plants with sodium nitroprusside remarkably increased Ascorbate peroxidase activity, while Spermidin pre-treatment significantly increased guaiacol peroxidase activity. Application of sodium nitroprusside or Spermidin with Methylene blue which is known to block cyclic guanosine monophosphate signaling pathway, reduced the protective effects of sodium nitroprussideand Spermidin in plants under salinity condition. The result of this study indicated that Methylene blue could partially and entirely abolish the protective effect of Nitric oxide on some physiological parameter. Methylene blue also has could reduce the alleviation effect of Spermidin on some of parameters in chamomile plant under salt stress, so with comparing the results of this study it seems that Spermidin probably acts through Nitric oxide pathway, but the use of 2-4- carboxyphenyl- 4,4,5,5- tetramethyl-imidazoline-1-oxyl-3-oxide is better to prove.

  19. Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions.

    Science.gov (United States)

    Andreozzi, R; Canterino, M; Caprio, V; Di Somma, I; Sanchirico, R

    2006-12-01

    Runaway phenomena and thermal explosions can originate during the nitration of salicylic acid by means of a nitric acid/acetic acid mixture when the thermal control is lost, mainly as a result of the formation and thermal decomposition of picric acid. The prediction of the behaviour of this system is thus of great importance in view of possible industrial applications and the need to avoid the occurrence of unwanted dangerous events. During a previous investigation a model was developed to simulate its behaviour when the starting concentration of the substrate is too low, thus, preventing the precipitation of poor soluble intermediates. In this work this model is extended to deal with more concentrated systems even in case of a solid phase separating during the process. To this purpose the previously assessed dependence of the solubility of 3-nitro and 5-nitrosalicylic acids upon temperature and nitric acid concentration is included in the model. It is assumed that when 3-nitro and 5-nitrosalicylic acids are partially suspended in the reacting medium a kinetic regime of "dissolution with reaction" is established; that is, the redissolution of these species is a fast process compared to the successive nitration to give dinitroderivatives. Good results are obtained in the comparison of the experimental data with those calculated both in isoperibolic and adiabatic conditions when the revised model is used.

  20. Inhibition of nitric oxide synthase expression in activated microglia and peroxynitrite scavenging activity by Opuntia ficus indica var. saboten.

    Science.gov (United States)

    Lee, Ming Hong; Kim, Jae Yeon; Yoon, Jeong Hoon; Lim, Hyo Jin; Kim, Tae Hee; Jin, Changbae; Kwak, Wie-Jong; Han, Chang-Kyun; Ryu, Jae-Ha

    2006-09-01

    Activated microglia by neuronal injury or inflammatory stimulation overproduce nitric oxide (NO) by inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) such as superoxide anion, resulting in neurodegenerative diseases. The toxic peroxynitrite (ONOO-), the reaction product of NO and superoxide anion further contributes to oxidative neurotoxicity. A butanol fraction obtained from 50% ethanol extracts of Opuntia ficus indica var. saboten (Cactaceae) stem (SK OFB901) and its hydrolysis product (SK OFB901H) inhibited the production of NO in LPS-activated microglia in a dose dependent manner (IC50 15.9, 4.2 microg/mL, respectively). They also suppressed the expression of protein and mRNA of iNOS in LPS-activated microglial cells at higher than 30 microg/mL as observed by western blot analysis and RT-PCR experiment. They also inhibited the degradation of I-kappaB-alpha in activated microglia. Moreover, they showed strong activity of peroxynitrite scavenging in a cell free bioassay system. These results imply that Opuntia ficus indica may have neuroprotective activity through the inhibition of NO production by activated microglial cells and peroxynitrite scavenging activity. Copyright (c) 2006 John Wiley & Sons, Ltd.

  1. Image analysis of epicuticular damage to foliage caused by dry deposition of the air pollutant nitric acid

    Science.gov (United States)

    Pamela E. Padgett; Sally D. Parry; Andrzej Bytnerowicz; Robert L. Heath

    2009-01-01

    Nitric acid vapor is produced by the same photochemical processes that produce ozone. In the laboratory, concentrated nitric acid is a strong acid and a powerful oxidant. In the environment, where the concentrations are much lower, it is an innocuous source of plant nitrogen. As an air pollutant, which mode of action does dry deposition of nitric...

  2. DMPD: Regulation of nitric oxide synthesis and apoptosis by arginase and argininerecycling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17513437 Regulation of nitric oxide synthesis and apoptosis by arginase and arginin...on of nitric oxide synthesis and apoptosis by arginase and argininerecycling. PubmedID 17513437 Title Regula...tion of nitric oxide synthesis and apoptosis by arginase and argininerecycling. A

  3. Airborne measurements of the nitric acid partitioning in persistent contrails

    Directory of Open Access Journals (Sweden)

    Th. Peter

    2009-11-01

    Full Text Available This study reports the first systematic measurements of nitric acid (HNO3 uptake in contrail ice particles at typical aircraft cruise altitudes. During the CIRRUS-III campaign cirrus clouds and almost 40 persistent contrails were probed with in situ instruments over Germany and Northern Europe in November 2006. Besides reactive nitrogen, water vapor, cloud ice water content, ice particle size distributions, and condensation nuclei were measured during 6 flights. Contrails with ages up to 12 h were detected at altitudes 10–11.5 km and temperatures 211–220 K. These contrails had a larger ice phase fraction of total nitric acid (HNO3ice/HNO3tot = 6% than the ambient cirrus layers (3%. On average, the contrails contained twice as much HNO3ice as the cirrus clouds, 14 pmol/mol and 6 pmol/mol, respectively. Young contrails with ages below 1 h had a mean HNO3ice of 21 pmol/mol. The contrails had higher nitric acid to water molar ratios in ice and slightly higher ice water contents than the cirrus clouds under similar meteorological conditions. The differences in ice phase fractions and molar ratios between developing contrails and cirrus are likely caused by high plume concentrations of HNO3 prior to contrail formation. The location of the measurements in the upper region of frontal cirrus layers might account for slight differences in the ice water content between contrails and adjacent cirrus clouds. The observed dependence of molar ratios as a function of the mean ice particle diameter suggests that ice-bound HNO3 concentrations are controlled by uptake of exhaust HNO3 in the freezing plume aerosols in young contrails and subsequent trapping of ambient HNO3 in growing ice particles in older (age > 1 h contrails.

  4. Nitric oxide and hydrogen peroxide in tomato resistance. Nitric oxide modulates hydrogen peroxide level in o-hydroxyethylorutin-induced resistance to Botrytis cinerea in tomato.

    Science.gov (United States)

    Małolepsza, Urszula; Rózalska, Sylwia

    2005-06-01

    Nitric oxide (NO) has been postulated to be required, together with reactive oxygen species (ROS), for activation of disease resistance reactions of plants to infection with a pathogen or elicitor treatment. However, biochemical mechanisms by which ROS and NO participate in these reactions are still under intensive study and controversial debate. We previously demonstrated that o-hydroxyethylorutin when applied on tomato leaves (Lycopersicon esculentum Mill. cv. "Perkoz") restricted Botrytis cinerea infection development. In this research we investigated ROS and NO generation in tomato plants treated with o-hydroxyethylorutin, non-treated and infected ones. The NO content was enhanced or decreased in the studied plants by supplying them with NO generator-SNP or scavenger-cPTIO. NO detection was carried out using diaminofluorescein diacetate (DAF-DA) in conjunction with confocal laser scanning microscopy. The influence of elevated and decreased levels of NO on B. cinerea infection development and ROS generation was studied. The elevated NO concentration in tomato leaves strongly decreased hydrogen peroxide concentration without affecting other studied ROS (superoxide anion and hydroxyl radical) levels. H2O2 concentrations in NO-supplied leaves were low regardless of further treatment of tomato leaves with o-hydroxyethylorutin or inoculation with B. cinerea. The low H2O2 concentration coincided with quick and severe infection development in NO-supplied leaves. As activities of enzymes generating (SOD EC 1.15.1.1)) and removing (APX EC 1.11.1.11, CAT EC 1.11.1.6) H2O2 were unchanged in the studied plants, the decrease in H2O2 concentration was probably due to a direct NO-H2O2 interaction.

  5. Nitric oxide reduces aluminum toxicity by preventing oxidative stress in the roots of Cassia tora L.

    Science.gov (United States)

    Wang, You-Sheng; Yang, Zhi-Min

    2005-12-01

    Nitric oxide (NO) as a key signaling molecule has been involved in mediation of various biotic and abiotic stress-induced physiological responses in plants. In the present study, we investigated the effect of NO on Cassia tora L. plants exposed to aluminum (Al). Plants pre-treated for 12 h with 0.4 mM sodium nitroprusside (SNP), an NO donor, and subsequently exposed to 10 microM Al treatment for 24 h exhibited significantly greater root elongation as compared with the plants without SNP treatment. The NO-promoted root elongation was correlated with a decrease in Al accumulation in root apexes. Furthermore, oxidative stress associated with Al treatment increased lipid peroxidation and reactive oxygen species, and the activation of lipoxygenase and antioxidant enzymes was reduced by NO. Such effects were confirmed by the histochemical staining for the detection of peroxidation of lipids and loss of membrane integrity in roots. The ameliorating effect of NO was specific, because the NO scavenger cPTIO [2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylinidazoline-1-oxyl-3-oxide] completely reversed the effect of NO on root growth in the presence of Al. These results indicate that NO plays an important role in protecting the plant against Al-induced oxidative stress.

  6. Roles of Glutamates and Metal ions in a Rationally Designed Nitric Oxide Reductase Based on Myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Y Lin; N Yeung; Y Gao; K Miner; S Tian; H Robinson; Y Lu

    2011-12-31

    A structural and functional model of bacterial nitric oxide reductase (NOR) has been designed by introducing two glutamates (Glu) and three histidines (His) in sperm whale myoglobin. X-ray structural data indicate that the three His and one Glu (V68E) residues bind iron, mimicking the putative FeB site in NOR, while the second Glu (I107E) interacts with a water molecule and forms a hydrogen bonding network in the designed protein. Unlike the first Glu (V68E), which lowered the heme reduction potential by {approx}110 mV, the second Glu has little effect on the heme potential, suggesting that the negatively charged Glu has a different role in redox tuning. More importantly, introducing the second Glu resulted in a {approx}100% increase in NOR activity, suggesting the importance of a hydrogen bonding network in facilitating proton delivery during NOR reactivity. In addition, EPR and X-ray structural studies indicate that the designed protein binds iron, copper, or zinc in the FeB site, each with different effects on the structures and NOR activities, suggesting that both redox activity and an intermediate five-coordinate heme-NO species are important for high NOR activity. The designed protein offers an excellent model for NOR and demonstrates the power of using designed proteins as a simpler and more well-defined system to address important chemical and biological issues.

  7. Flame thermometry using laser-induced-grating spectroscopy of nitric oxide

    Science.gov (United States)

    Luers, Andrew; Salhlberg, Anna-Lena; Hochgreb, Simone; Ewart, Paul

    2018-03-01

    A systematic study of laser-induced thermal-grating scattering (LITGS) using nitric oxide as an absorbing species is presented as a means of thermometry in air-fed combustion. The relative contributions to the scattered signal from degenerate four-wave mixing, DFWM, and from laser-induced thermal-grating scattering, LITGS, are studied in the time domain for NO in N2 buffer gas up to 4 bar, using a pulsed laser system to excite the (0,0) γ-bands of NO at 226.21 nm. LITGS signals from combustion-generated NO in a laminar, pre-mixed CH4/O2/N2 flame on an in-house constructed slot burner were used to derive temperature values as a function of O2 concentration and position in the flame at 1 and 2.5 bar total pressure. Temperature values consistent with the calculated adiabatic flame temperature were derived from averaged LITGS signals over 50-100 single shots at 10 Hz repetition rate in the range 1600-2400 K with a pressure-dependent uncertainty of ± 1.8% at 1 bar to ± 1.4% at 2.5 bar. Based on observed signal-to-noise ratios, the minimum detectable concentration of NO in the flame is estimated to be 80 ppm for a 5 s measurement time at 10 Hz repetition rate.

  8. Synergistic effects between catalase inhibitors and modulators of nitric oxide metabolism on tumor cell apoptosis.

    Science.gov (United States)

    Scheit, Katrin; Bauer, Georg

    2014-10-01

    Inhibitors of catalase (such as ascorbate, methyldopa, salicylic acid and neutralizing antibodies) synergize with modulators of nitric oxide (NO) metabolism (such as arginine, arginase inhibitor, NO synthase-inducing interferons and NO dioxygenase inhibitors) in the singlet oxygen-mediated inactivation of tumor cell protective catalase. This is followed by reactive oxygen species (ROS)-dependent apoptosis induction. TGF-beta, NADPH oxidase-1, NO synthase, dual oxidase-1 and caspase-9 are characterized as essential catalysts in this process. The FAS receptor and caspase-8 are required for amplification of ROS signaling triggered by individual compounds, but are dispensable when the synergistic effect is established. Our findings explain the antitumor effects of catalase inhibitors and of compounds that target NO metabolism, as well as their synergy. These data may have an impact on epidemiological studies related to secondary plant compounds and open new perspectives for the establishment of novel antitumor drugs and for the improvement of established chemotherapeutics. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  9. The NADPH oxidase inhibitor apocynin induces nitric oxide synthesis via oxidative stress

    International Nuclear Information System (INIS)

    Riganti, Chiara; Costamagna, Costanzo; Doublier, Sophie; Miraglia, Erica; Polimeni, Manuela; Bosia, Amalia; Ghigo, Dario

    2008-01-01

    We have recently shown that apocynin elicits an oxidative stress in N11 mouse glial cells and other cell types. Here we report that apocynin increased the accumulation of nitrite, the stable derivative of nitric oxide (NO), in the extracellular medium of N11 cell cultures, and the NO synthase (NOS) activity in cell lysates. The increased synthesis of NO was associated with increased expression of inducible NOS (iNOS) mRNA, increased nuclear translocation of the redox-sensitive transcription factor NF-κB and decreased intracellular level of its inhibitor IkBα. These effects, accompanied by increased production of H 2 O 2 , were very similar to those observed after incubation with bacterial lipopolysaccharide (LPS) and were inhibited by catalase. These results suggest that apocynin, similarly to LPS, induces increased NO synthesis by eliciting a generation of reactive oxygen species (ROS), which in turn causes NF-κB activation and increased expression of iNOS. Therefore, the increased bioavailability of NO reported in the literature after in vivo or in vitro treatments with apocynin might depend, at least partly, on the drug-elicited induction of iNOS, and not only on the inhibition of NADPH oxidase and the subsequent decreased scavenging of NO by oxidase-derived ROS, as it is often supposed

  10. Nitric oxide, cytochrome C oxidase, and the cellular response to hypoxia.

    Science.gov (United States)

    Taylor, Cormac T; Moncada, Salvador

    2010-04-01

    Cytochrome c oxidase (CcO; complex IV of the mitochondrial electron transport chain) is the primary site of cellular oxygen consumption and, as such, is central to oxidative phosphorylation and the generation of adenosine-triphosphate. Nitric oxide (NO), an endogenously-generated gas, modulates the activity of CcO. Depending on the intracellular oxygen concentration and the resultant dominant redox state of CcO, the interaction between CcO and NO can have a range of signaling consequences for cells in the perception of changes in oxygen concentration and the initiation of adaptive responses. At higher oxygen concentrations, when CcO is predominantly in an oxidized state, it consumes NO. At lower oxygen concentrations, when CcO is predominantly reduced, NO is not consumed and accumulates in the microenvironment, with implications for both the respiratory rate of cells and the local vascular tone. Changes in the availability of intracellular oxygen and in the generation of reactive oxygen species that accompany these interactions result in cell signaling and in regulation of oxygen-sensitive pathways that ultimately determine the nature of the cellular response to hypoxia.

  11. Chronic nitric oxide deprivation induces an adaptive antioxidant status in human endothelial cells.

    Science.gov (United States)

    Cattaneo, Maria Grazia; Cappellini, Elisa; Ragni, Maurizio; Tacchini, Lorenza; Scaccabarozzi, Diletta; Nisoli, Enzo; Vicentini, Lucia Maria

    2013-11-01

    In a previous work, we showed an increased cell motility due to the accumulation and transcriptional activation of the Hypoxia Inducible Factor-1α (HIF-1α) and a reduced mitochondrial energy production in an in vitro model of endothelial dysfunction (ED) represented by human endothelial cells (ECs) chronically deprived of nitric oxide (NO) by L-NAME treatment. In the present study, in the attempt to unravel the pathway(s) linking NO deficiency to HIF-1α accumulation and activation, we focused our attention on Reactive Oxygen Species (ROS). We found that ROS were partially involved in HIF-1α stabilization, but not in the pro-migratory phenotype. Regarding mitochondrial dysfunction, it did not require neither ROS generation nor HIF-1α activity, and was not due to autophagy. Very interestingly, while acute treatment with L-NAME induced a transient increase in ROS formation, chronic NO deprivation by long term L-NAME exposure drastically reduced cellular ROS content giving rise to an antioxidant environment characterized by an increase in superoxide dismutase-2 (SOD-2) expression and activity, and by nuclear accumulation of the transcription factor NF-E2-related factor-2 (Nrf2). These results might have important implications for our understanding of the consequences of NO deprivation in endothelium behavior and in the onset of cardiovascular diseases. © 2013.

  12. Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses.

    Science.gov (United States)

    Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Cheng, Min; Zhang, Xiaomin; Liu, Lei

    2018-03-09

    Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species ( Quercus glauca ) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500-660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca . These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

  13. Defense gene induction in tobacco by nitric oxide, cyclic GMP, and cyclic ADP-ribose.

    Science.gov (United States)

    Durner, J; Wendehenne, D; Klessig, D F

    1998-08-18

    Reactive oxygen species are believed to perform multiple roles during plant defense responses to microbial attack, acting in the initial defense and possibly as cellular signaling molecules. In animals, nitric oxide (NO) is an important redox-active signaling molecule. Here we show that infection of resistant, but not susceptible, tobacco with tobacco mosaic virus resulted in enhanced NO synthase (NOS) activity. Furthermore, administration of NO donors or recombinant mammalian NOS to tobacco plants or tobacco suspension cells triggered expression of the defense-related genes encoding pathogenesis-related 1 protein and phenylalanine ammonia lyase (PAL). These genes were also induced by cyclic GMP (cGMP) and cyclic ADP-ribose, two molecules that can serve as second messengers for NO signaling in mammals. Consistent with cGMP acting as a second messenger in tobacco, NO treatment induced dramatic and transient increases in endogenous cGMP levels. Furthermore, NO-induced activation of PAL was blocked by 6-anilino-5,8-quinolinedione and 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalin-1-one, two inhibitors of guanylate cyclase. Although 6-anilino-5,8-quinolinedione fully blocked PAL activation, inhibition by 1H-(1,2,4)-oxadiazole[4, 3-a]quinoxalin-1-one was not entirely complete, suggesting the existence of cGMP-independent, as well as cGMP-dependent, NO signaling. We conclude that several critical players of animal NO signaling are also operative in plants.

  14. Cytoglobin Is Expressed in the Vasculature and Regulates Cell Respiration and Proliferation via Nitric Oxide Dioxygenation*

    Science.gov (United States)

    Halligan, Katharine E.; Jourd'heuil, Frances L.; Jourd'heuil, David

    2009-01-01

    Disposition of the second messenger nitric oxide (NO) in mammalian tissues occurs through multiple pathways including dioxygenation by erythrocyte hemoglobin and red muscle myoglobin. Metabolism by a putative NO dioxygenase activity in non-striated tissues has also been postulated, but the exact nature of this activity is unknown. In the present study, we tested the hypothesis that cytoglobin, a newly discovered hexacoordinated globin, participates in cell-mediated NO consumption. Stable expression of small hairpin RNA targeting cytoglobin in fibroblasts resulted in decreased NO consumption and intracellular nitrate production. These cells were more sensitive to NO-induced inhibition of cell respiration and proliferation, which could be restored by re-expression of human cytoglobin. We also demonstrated cytoglobin expression in adventitial fibroblasts as well as vascular smooth muscle cells from various species including human and found that cytoglobin was expressed in the adventitia and media of intact rat aorta. These results indicate that cytoglobin contributes to cell-mediated NO dioxygenation and represents an important NO sink in the vascular wall. PMID:19147491

  15. Cytoglobin is expressed in the vasculature and regulates cell respiration and proliferation via nitric oxide dioxygenation.

    Science.gov (United States)

    Halligan, Katharine E; Jourd'heuil, Frances L; Jourd'heuil, David

    2009-03-27

    Disposition of the second messenger nitric oxide (NO) in mammalian tissues occurs through multiple pathways including dioxygenation by erythrocyte hemoglobin and red muscle myoglobin. Metabolism by a putative NO dioxygenase activity in non-striated tissues has also been postulated, but the exact nature of this activity is unknown. In the present study, we tested the hypothesis that cytoglobin, a newly discovered hexacoordinated globin, participates in cell-mediated NO consumption. Stable expression of small hairpin RNA targeting cytoglobin in fibroblasts resulted in decreased NO consumption and intracellular nitrate production. These cells were more sensitive to NO-induced inhibition of cell respiration and proliferation, which could be restored by re-expression of human cytoglobin. We also demonstrated cytoglobin expression in adventitial fibroblasts as well as vascular smooth muscle cells from various species including human and found that cytoglobin was expressed in the adventitia and media of intact rat aorta. These results indicate that cytoglobin contributes to cell-mediated NO dioxygenation and represents an important NO sink in the vascular wall.

  16. Enhancing Growth in Eucomis autumnalis (Mill. Chitt. Seedlings with Exogenous Application of Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Salachna Piotr

    2016-12-01

    Full Text Available Nitric oxide (NO is a molecule that regulates biological processes in plants and may be used in horticultural practice as a potential plant growth regulator. Eucomis autumnalis (Mill. Chitt., also known as pineapple lily, is a member of the Asparagaceae and native to South Africa. Pineapple lily are well suited for production as pot plants, cut flowers, and garden plants. The potential also exists for this species to be used as a medicinal plant. The aim of the study was to assess the effects of the NO donor of sodium nitroprusside (SNP on morphological features of E. autumnalis seedlings. The plants grown in a greenhouse were drenched four times, at weekly intervals, with SNP solutions of the following concentration: 0, 100, 200, 300, 400, and 500 μM. The study revealed that the application of SNP significantly improved greenness index of leaves, leaf length, and leaf fresh weight, as compared to the control at all levels. This treatment also showed a significant increase in bulb and root fresh weight, root number, and root length. Application of SNP at 200 μM increased the values of the attributes studied to the maximum extent.

  17. Silver Modified Degussa P25 for the Photocatalytic Removal of Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Neil Bowering

    2007-01-01

    Full Text Available A study of the photocatalytic behaviour of silver modified titanium dioxide materials for the decomposition and reduction of nitric oxide (NO gas has been carried out. The effects of silver loading, calcination temperature, and reaction conditions have been investigated. Prepared photocatalysts were characterised using XRD, TEM, and XPS. A continuous flow reactor was used to determine the photocatalytic activity and selectivity of NO decomposition in the absence of oxygen as well as NO reduction using CO as the reducing agent, over the prepared photocatalysts. XRD and TEM analysis of the photocatalysts showed that crystalline silver nitrate particles were present on the titanium dioxide surface after calcination at temperatures of up to 200∘C. The silver nitrate particles are thermally decomposed to form metallic silver clusters at higher temperatures. XPS analysis of the photocatalysts showed that for each of the temperatures used, both Ag+ and Ag0 were present and that the Ag0/Ag+ ratio increased with increasing calcination temperature. The presence of metallic silver species on the TiO2 surface dramatically increased the selectivity for N2 formation of both decomposition and reduction reactions. When CO was present in the reaction gas, selectivities of over 90% were observed for all the Ag-TiO2 photocatalysts that had been calcined at temperatures above 200∘C. Unfortunately these high selectivities were at the expense of photocatalytic activity, with lower NO conversion rates than those achieved over unmodified TiO2 photocatalysts.

  18. Nitric oxide protects carbon assimilation process of watermelon from boron-induced oxidative injury.

    Science.gov (United States)

    Farag, Mohamed; Najeeb, Ullah; Yang, Jinghua; Hu, Zhongyuan; Fang, Zhang Ming

    2017-02-01

    Nitric oxide (NO) mediates plant response to a variety of abiotic stresses; however, limited information is available on its effect on boron (B)-stressed watermelon plants. The present study investigates the mechanism through which NO protects watermelon seedlings from B deficiency and toxicity stresses. Five days old watermelon seedlings were exposed to B (0, 0.5 and 10 mg L -1 ) alone or with 75 μmole of NO donor sodium nitroprusside (SNP) for 30 days. Both low and high B concentrations in the media altered nutrient accumulation and impaired various physiological processes of watermelon seedlings, leading to a significant reduction in biomass production. The plants exposed to B deficient or toxic concentrations had 66 and 69% lower shoot dry weight, respectively compared with optimum B levels. B toxicity-induced growth inhibition of watermelon seedlings was associated with high B translocation to shoot tissues, which caused lipid membrane peroxidation (12% increase) and chlorophyll destruction (25% reduction). In contrast, B deficiency accelerated generation of reactive oxygen species (ROS), specifically OH -1 and induced cellular oxidative injury. Exogenously applied SNP promoted leaf chlorophyll, photosynthesis and consequently biomass production in B-stressed watermelon seedlings by reducing B accumulation, lipid membrane peroxidation and ROS generation. It also activated antioxidant enzymes such as SOD, POD and APX, and protected the seedlings from ROS-induced cellular burst. Copyright © 2016. Published by Elsevier Masson SAS.

  19. Enhancing vascular relaxing effects of nitric oxide-donor ruthenium complexes.

    Science.gov (United States)

    Paulo, Michele; Banin, Tamy M; de Andrade, Fernanda A; Bendhack, Lusiane M

    2014-05-01

    Ruthenium-derived complexes have emerged as new nitric oxide (NO) donors that may help circumvent the NO deficiency that impairs vasodilation. NO in vessels can be produced by the endothelial cells and/or released by NO donors. NO interacts with soluble guanylyl-cyclase to produce cGMP to activate the kinase-G pathway. As a result, conductance arteries, veins and resistance arteries dilate, whereas the cytosolic Ca(2+) levels in the smooth muscle cells decrease. NO also reacts with oxygen or the superoxide anion, to generate reactive oxygen species that modulate NO-induced vasodilation. In this article, we focus on NO production by NO synthase and discuss the vascular changes taking place during hypertension originating from endothelial dysfunction. We will describe how the NO released from ruthenium-derived complexes enhances the vascular effects arising from failed NO generation or lack of NO bioavailability. In addition, how ruthenium-derived NO donors induce the hypotensive effect by vasodilation is also discussed.

  20. Lipid peroxidation and cell death mechanisms in pulmonary epithelial cells induced by peroxynitrite and nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Yuan-Soon [School of Medical Technology, Taipei Medical University, Taipei (Taiwan); Liou, Hung-Bin; Lin, Yu-Ping; Guo, How-Ran; Ho, Sheng-Yow; Lee, Ching-Chang; Wang, Ying-Jan [Department of Environmental and Occupational Health, National Cheng Kung University Medical College, 138 Sheng-Li Road, Tainan (Taiwan); Lin, Jen-Kun; Pan, Min-Hsiung [Institute of Biochemistry, National Taiwan University, Medical College, Taipei (Taiwan); Jeng, Jiiang-Huei [School of Dentistry, National Taiwan University and Hospital, Medical College, Taipei (Taiwan)

    2002-08-01

    Nitric oxide (NO) is an environmental pollutant found in smog and cigarette smoke. Recently, NO has been discovered to act as a molecular messenger, mediating various physiological functions. However, when an excess of NO is present, cytotoxic and mutagenic effects can also be induced. The reaction of NO with superoxide results in the formation of peroxynitrite (ONOO{sup -}), which decomposes into the hydroxyl radical and nitrogen dioxide. Both of them are potent oxidant species that may initiate and propagate lipid peroxidation. In the present study, we examined the effects of NO and ONOO{sup -} on the induction of lipid peroxidation and cell death mechanisms in rats and in A549 pulmonary epithelial cells. The results showed that ONOO{sup -} is able to induce lipid peroxidation in pulmonary epithelial cells in a dose-dependent manner. 8-Epi-prostaglandin F{sub 2{alpha}} can serve as a good biomarker of lipid peroxidation both in vitro and in vivo. Postmitotic apoptosis was found in A549 cells exposed to NO, whereas ONOO{sup -} induced cell death more characteristic of necrosis than apoptosis. Apoptosis that occurred in cells may be related to the dysfunction of mitochondria, the release of cytochrome c into cytosol, and the activation of caspase-9. The relationship between caspase activation and the cleavage of other death substrates during postmitotic apoptosis in A549 cells needs further investigation. (orig.)

  1. Nitric oxide counters ethylene effects on ripening fruits.

    Science.gov (United States)

    Manjunatha, Girigowda; Gupta, Kapuganti J; Lokesh, Veeresh; Mur, Luis A J; Neelwarne, Bhagyalakshmi

    2012-04-01

    Ethylene plays a key role in promoting fruit ripening, so altering its biosynthesis/signaling could be an important means to delay this process. Nitric oxide (NO)-generated signals are now being shown to regulate ethylene pathways. NO signals have been shown to transcriptionally repress the expression of genes involved in ethylene biosynthesis enzymes and post-translationally modify methionine adenosyl transferase (MAT) activity through S-nitrosylation to reduce the availably of methyl groups required to produce ethylene. Additionally, NO cross-talks with plant hormones and other signal molecules and act to orchestrate the suppression of ethylene effects by modulating enzymes/proteins that are generally triggered by ethylene signaling at post-climacteric stage. Thus, medication of endogenous NO production is suggested as a strategy to postpone the climacteric stage of many tropical fruits.

  2. Weaning of inhaled nitric oxide: is there a best strategy?

    Directory of Open Access Journals (Sweden)

    Anita M. Ware

    2015-04-01

    Full Text Available Background: Inhaled nitric oxide (iNO has been used in the treatment of pulmonary hypertension in neonates for many years. iNO was approved by the FDA in 1999 for hypoxic respiratory failure (HRF in term and near term infants, defined as > 34 weeks gestational age (GA. iNO is used for persistent pulmonary hypertension of the newborn (PPHN, secondary pulmonary hypertension caused by congenital heart disease (CHD, congenital diaphragmatic hernia (CDH, meconium aspiration syndrome (MAS, pneumonia, respiratory distress syndrome (RDS, and other pathologies. iNO has its effect locally on the pulmonary vasculature and has been studied extensively regarding its effect on morbidities such as: need for extracorporeal membrane oxygenation (ECMO, oxygen requirements, and mechanical ventilatory support. However, protocols for weaning iNO and for the duration of iNO weaning have not been studied extensively. It has been shown that an abrupt discontinuation leads to rebound pulmonary hypertension.Methods: Electronic literature search and review of published articles on the use of iNO in the neonate.Results: Electronic databases including Medline and PubMed were searched from the years 1995-2015, using the keywords "iNO", "nitric oxide", "neonate", and "weaning nitric oxide." This search revealed 2,124 articles. Articles were determined to be eligible for review if they included a specific protocol for weaning iNO, and were published in English. 16 articles with specific protocols for iNO weaning have been identified and reviewed. The studies had enrolled a total of 1,735 neonates either at term either preterm and with a mean birth weight of 3.3 kg (± 2 kg. Main diagnoses included MAS, CHD (total anomalous pulmonary venous return [TAPVR], d-transposition of the great vessels [DTGV], atrial septal defect [ASD], pulmonary atresia [PA], hypoplastic left heart syndrome [HLH], pneumonia, RDS, hyaline membrane disease (HMD, PPHN, CDH, sepsis, pulmonary hypoplasia

  3. Antioxidant and nitric oxide synthase activation properties of Ganoderma applanatum.

    Science.gov (United States)

    Acharya, Krishnendu; Yonzone, Parinita; Rai, Manjula; Rupa, Acharya

    2005-10-01

    In vitro evaluation of antioxidant activities of Ganoderma applanatum showed significant inhibition of lipid peroxidation, and potent hydroxyl radical scavenging activity when compared with standard drug catechin. IC50 values of crude, boiled and ethanolic extracts of G. applanatum were 604.8, 624 and 267 microg/ml, respectively in case of hydroxyl radical scavenging activity, and 441, 520.5 and 166.16 microg/ml, respectively in case of lipid peroxidation. Furthermore, crude, boiled and ethanolic extracts also increased significantly nitric oxide production (156.67, 121.88 and 742 pmole/mg dry wt/hr, respectively) over the control. The results of present investigation revealed that G. applanatum have potential therapeutic use.

  4. Estimation of nitric oxide as an inflammatory marker in periodontitis

    Directory of Open Access Journals (Sweden)

    Menaka K

    2009-01-01

    Full Text Available Nitric oxide (NO is not only important in host defense and homeostasis but it is also regarded as harmful and has been implicated in the pathogenesis of a wide variety of inflammatory and autoimmune diseases. The presence of NO in periodontal disease may reflect the participation of an additional mediator of bone resorption responsible for disease progression. The aim of this study was to assess the level of NO in serum in chronic periodontitis, and correlate these levels with the severity of periodontal disease. Sixty subjects participated in the study and were divided into two groups. NO levels were assayed by measuring the accumulation of stable oxidative metabolite, nitrite with Griess reaction. Results showed subjects with periodontitis had significantly high nitrite in serum than healthy subjects. NO production is increased in periodontal disease, this will enable us to understand its role in disease progression and selective inhibition of NO may be of therapeutic utility in limiting the progression of periodontitis.

  5. Nanomaterials-based electrochemical sensors for nitric oxide

    International Nuclear Information System (INIS)

    Dang, Xueping; Hu, Hui; Wang, Shengfu; Hu, Shengshui

    2015-01-01

    Electrochemical sensing has been demonstrated to represent an efficient way to quantify nitric oxide (NO) in challenging physiological environments. A sensing interface based on nanomaterials opens up new opportunities and broader prospects for electrochemical NO sensors. This review (with 141 refs.) gives a general view of recent advances in the development of electrochemical sensors based on nanomaterials. It is subdivided into sections on (i) carbon derived nanomaterials (such as carbon nanotubes, graphenes, fullerenes), (ii) metal nanoparticles (including gold, platinum and other metallic nanoparticles); (iii) semiconductor metal oxide nanomaterials (including the oxides of titanium, aluminum, iron, and ruthenium); and finally (iv) nanocomposites (such as those formed from carbon nanomaterials with nanoparticles of gold, platinum, NiO or TiO 2 ). The various strategies are discussed, and the advances of using nanomaterials and the trends in NO sensor technology are outlooked in the final section. (author)

  6. Exhaled nitric oxide concentration in patients after heart transplantation.

    Science.gov (United States)

    Nadziakiewicz, P; Knapik, P; Zakliczyński, M; Zembala, M; Urbańska, E; Pacholewicz, J

    2007-11-01

    Nitric oxide (NO) is present in exhaled air in humans and its level may decrease in heart diseases. In the present study we prospectively investigated how heart transplantation treated with oral immunosuppresive drugs based on ciclosporine A influences the exhaled NO concentration (exNO). The study was performed in 17 patients after heart transplantation in various time after procedure and 15 nonsmoking healthy volunteers as a control group. Patients after heart transplantation were free of clinical signs of rejection. End-tidal concentration of exNO was measured by the use of a chemiluminescence method. We found no statistically significant differences in the exNO level between patients after heart transplantation and healthy controls (6.81+/-2.70 part per billion (ppb) in the transplant group vs. 6.01+/-3.43 ppb in the control group). We conclude that heart transplantation and immunosuppresive therapy do not influence the exhaled NO concentration.

  7. Localization of nitric oxide synthase in human skeletal muscle

    DEFF Research Database (Denmark)

    Frandsen, Ulrik; Lopez-Figueroa, M.; Hellsten, Ylva

    1996-01-01

    The present study investigated the cellular localization of the neuronal type I and endothelial type III nitric oxide synthase in human skeletal muscle. Type I NO synthase immunoreactivity was found in the sarcolemma and the cytoplasm of all muscle fibres. Stronger immunoreactivity was expressed...... in the sarcolemma as well as the cytoplasm of type I muscle fibres. NADPH diaphorase activity confirmed a higher level of NO synthase activity in the sarcolemma as well as the cytoplasm of type I muscle fibers. Histochemical staining for cytochrome oxidase showed a staining pattern similar to that observed for type...... I NO synthase immunoreactivity and NADPH diaphorase activity. Type III NO synthase immunoreactivity was observed both in the endothelium of larger vessels and of microvessels. The results establish that human skeletal muscle expresses two different constitutive isoforms of NO synthase in different...

  8. Localization of Nitric Oxide in Wheat Roots by DAF Fluorescence.

    Science.gov (United States)

    Wany, Aakanksha; Gupta, Kapuganti Jagadis

    2016-01-01

    Nitric oxide is a free radical signal molecule. Various methods are available for measurement of NO. Out of all methods, fluorescent probes to localize NO is very widely used method. Diaminofluorescein in diacetate form (DAF-2DA) is most widely probe for NO measurement. This method is based on application of 4,5-diaminofluorescein diacetate (DAF-2DA) which is actively diffused into cells, once taken up by cells cytoplasmic esterases cleave the acetate groups to generate 4,5-diaminofluorescein; DAF-2. The generated DAF-2 can readily react with N2O3, which is an oxidation product of NO to generate the highly fluorescent DAF-2T (triazolofluorescein). There are various advantages and disadvantages associated with this method, but to its advantage in diffusion closely to NO producing sites, it is widely used for localization studies. Here, we describe method to make sections of the roots and localization of NO in roots subjected to hypoxic stress.

  9. Exhaled nitric oxide and spirometry in respiratory health surveillance.

    Science.gov (United States)

    Bohadana, A B; Hannhart, B; Ghezzo, H; Teculescu, D; Zmirou-Navier, D

    2011-03-01

    Exposure to pollutants in bakeries and hairdressing salons can cause airway syndromes varying from bronchial irritation to asthma. Workplace respiratory health surveillance aims to identify possible cases requiring further investigation. To compare the performance of fractional exhaled nitric oxide (FE(NO)) and spirometry for health surveillance of apprentice bakers (ABs) and apprentice hairdressers (AHDs). Determinants of FE(NO) were also identified. Symptoms and physician-diagnosed asthma were evaluated by questionnaire. FE(NO) was measured and spirometry was carried out. Subjects with elevated FE(NO) (FE(NO) > upper limit normal), airway obstruction [forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) smokers compared with atopic smokers and non-atopic subjects (P spirometry were not overlapping dimensions in ABs and hairdressers, each test contributing unique information on the physiological status of the respiratory system. FE(NO) may provide added information on airway inflammation not provided by spirometry.

  10. Nitric Oxide And Hypoxia Response In Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Estefanía Caballano Infantes

    2015-08-01

    Full Text Available The expansion of pluripotent cells (ESCs and iPSCs under conditions that maintain their pluripotency is necessary to implement a cell therapy program. Previously, we have described that low nitric oxide (NO donor diethylenetriamine/nitric oxide adduct (DETA-NO added to the culture medium, promote the expansion of these cell types. The molecular mechanisms are not yet known. We present evidences that ESC and iPSCs in normoxia in presence of low NO triggers a similar response to hypoxia, thus maintaining the pluripotency. We have studied the stability of HIF-1α (Hypoxia Inducible Factor in presence of low NO. Because of the close relationship between hypoxia, metabolism, mitochondrial function and pluripotency we have analyzed by q RT-PCR the expression of genes involved in the glucose metabolism such as: HK2, LDHA and PDK1; besides other HIF-1α target gene. We further analyzed the expression of genes involved in mitochondrial biogenesis such as PGC1α, TFAM and NRF1 and we have observed that low NO maintains the same pattern of expression that in hypoxia. The study of the mitochondrial membrane potential using Mito-Tracker dye showed that NO decrease the mitochondrial function. We will analyze other metabolic parameters, to determinate if low NO regulates mitochondrial function and mimics Hypoxia Response. The knowledge of the role of NO in the Hypoxia Response and the mechanism that helps to maintain self-renewal in pluripotent cells in normoxia, can help to the design of culture media where NO could be optimal for stem cell expansion in the performance of future cell therapies.

  11. Radiosensitization of hypoxic tumor cells in vitro by nitric oxide

    International Nuclear Information System (INIS)

    Griffin, Robert J.; Makepeace, Carol M.; Hur, Won-Joo; Song, Chang W.

    1996-01-01

    Purpose: The effects of nitric oxide (NO) on the radiosensitivity of SCK tumor cells in oxic and hypoxic environments in vitro were studied. Methods and Materials: NO was delivered to cell suspensions using the NO donors 2,2-diethyl-1-nitroso-oxyhydrazine sodium salt (DEA/NO), and a spermine/nitric oxide complex (SPER/NO), which release NO at half-lives of 2.1 min and 39 min at pH 7.4, respectively. The cells were suspended in media containing DEA/NO or SPER/NO for varying lengths of time under oxic or hypoxic conditions, irradiated, and the clonogenicity determined. Results: Both compounds markedly radiosensitized the hypoxic cells. The drug enhancement ratios (DER) for 0.1, 1.0, and 2.0 mM DEA/NO were 2.0, 2.3 and 3.0, respectively, and those for 0.1, 1.0, and 2.0 mM SPER/NO were 1.6, 2.3, and 2.8, respectively. Aerobic cells were not radiosensitized by DEA/NO or SPER/NO. When DEA/NO and SPER/NO were incubated in solution overnight to allow release of NO, they were found to have no radiosensitizing effect under hypoxic or oxic conditions indicating the sensitization by the NO donors was due to the NO molecule released from these drugs. At the higher concentrations, SPER/NO was found to be cytotoxic in aerobic conditions but not in hypoxic conditions. DEA/NO was only slightly toxic to the cells in both aerobic and hypoxic conditions. Conclusions: NO released from NO donors DEA/NO and SPER/NO is as effective as oxygen to radiosensitize hypoxic cells in vitro. Its application to the radiosensitization of hypoxic cells in solid tumors remains to be investigated

  12. Decoding the substrate supply to human neuronal nitric oxide synthase.

    Directory of Open Access Journals (Sweden)

    Alexandra Simon

    Full Text Available Nitric oxide, produced by the neuronal nitric oxide synthase (nNOS from L-arginine is an important second messenger molecule in the central nervous system: It influences the synthesis and release of neurotransmitters and plays an important role in long-term potentiation, long-term depression and neuroendocrine secretion. However, under certain pathological conditions such as Alzheimer's or Parkinson's disease, stroke and multiple sclerosis, excessive NO production can lead to tissue damage. It is thus desirable to control NO production in these situations. So far, little is known about the substrate supply to human nNOS as a determinant of its activity. Measuring bioactive NO via cGMP formation in reporter cells, we demonstrate here that nNOS in both, human A673 neuroepithelioma and TGW-nu-I neuroblastoma cells can be fast and efficiently nourished by extracellular arginine that enters the cells via membrane transporters (pool I that is freely exchangeable with the extracellular space. When this pool was depleted, NO synthesis was partially sustained by intracellular arginine sources not freely exchangeable with the extracellular space (pool II. Protein breakdown made up by far the largest part of pool II in both cell types. In contrast, citrulline to arginine conversion maintained NO synthesis only in TGW-nu-I neuroblastoma, but not A673 neuroepithelioma cells. Histidine mimicked the effect of protease inhibitors causing an almost complete nNOS inhibition in cells incubated additionally in lysine that depletes the exchangeable arginine pool. Our results identify new ways to modulate nNOS activity by modifying its substrate supply.

  13. Nitric oxide as a potential biomarker in inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Nesina Avdagić

    2013-02-01

    Full Text Available The aim of this study was to investigate changes in serum nitric oxide (NO concentration in inflammatory bowel diseases (IBD patients and its use as potential biomarker in differential diagnosis of ulcerative colitis (UC and Crohn's disease (CD and in disease activity assessment. In 60 patients of both genders - 30 with ulcerative colitis and 30 with Crohn's disease - and 30 controls serum nitric oxide concentration was determined by measuring nitrite concentration, a stable metabolic product of NO with oxygen. Conversion of nitrates (NO3- to nitrites (NO2- was done with elementary zinc. The nitrite concentration was determined by classic colorimetrical Griess reaction. Median serum NO concentration was statistically different (p=0,0005 between UC patients (15.25 µmol/L; 13.47 - 19.88 µmol/L, CD patients (14.54 µmol/L; 13.03 -16.32 µmol/L and healthy controls (13.29 µmol/L; 12.40 - 13.92 µmol/L. When active UC and CD patients were compared with inactive UC and CD patients respectively a significant difference in serum NO level was found (p=0.0005. With a cut-off level of 17.39 µmol/L NO had a sensitivity of 100% and a specificity of 100% in discriminating between active and inactive UC patients. With cut-off value of 14.01 µmol/L serum NO level had a sensitivity of 88% and a specificity of 69% in distinguishing between patients with active CD and inactive CD. Serum NO concentration is a minimally invasive and rapid tool for discriminating between active and inactive IBD patients and could be used as useful biomarker in monitoring of disease activity in IBD patients.

  14. Effects of nitric oxide on neuromuscular properties of developing zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Michael Jay

    Full Text Available Nitric oxide is a bioactive signalling molecule that is known to affect a wide range of neurodevelopmental processes. However, its functional relevance to neuromuscular development is not fully understood. Here we have examined developmental roles of nitric oxide during formation and maturation of neuromuscular contacts in zebrafish. Using histochemical approaches we show that elevating nitric oxide levels reduces the number of neuromuscular synapses within the axial swimming muscles whilst inhibition of nitric oxide biosynthesis has the opposite effect. We further show that nitric oxide signalling does not change synapse density, suggesting that the observed effects are a consequence of previously reported changes in motor axon branch formation. Moreover, we have used in vivo patch clamp electrophysiology to examine the effects of nitric oxide on physiological maturation of zebrafish neuromuscular junctions. We show that developmental exposure to nitric oxide affects the kinetics of spontaneous miniature end plate currents and impacts the neuromuscular drive for locomotion. Taken together, our findings implicate nitrergic signalling in the regulation of zebrafish neuromuscular development and locomotor maturation.

  15. Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

    Science.gov (United States)

    Reger, Nina A.; Meng, Wilson S.; Gawalt, Ellen S.

    2017-04-01

    Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

  16. A comparison of three methods for determining the amount of nitric acid needed to treat HLW sludge at SRS

    International Nuclear Information System (INIS)

    Siegwald, S.F.; Ferrara, D.M.

    1994-01-01

    A comparison was made of three methods for determining the amount of nitric acid which will be needed to treat a sample of high-level waste (HLW) sludge from the Savannah River Site (SRS) Tank Farm. The treatment must ensure the resulting melter feed will have the necessary rheological and oxidation-reduction properties, reduce mercury and manganese in the sludge, and be performed in a fashion which does not produce a flammable gas mixture. The three methods examined where an empirical method based on pH measurements, a computational method based on known reactions of the species in the sludge and a titration based on neutralization of carbonate in the solution

  17. Induction of chilling tolerance in wheat during germination by pre-soaking seed with nitric oxide and gibberellin

    DEFF Research Database (Denmark)

    Li, Xiangnan; Jiang, Haidong; Liu, Fulai

    2013-01-01

    Chilling depresses seed germination and seedling establishment, and is one major constraint to grain yield formation in late sown winter wheat. Seeds of winter wheat (Triticum aestivum L.) were separately pre-soaked with sodium nitroprusside (SNP, as nitric oxide donor) and Gibberellic acid (GA3......) before germination and then germinated under low temperature. SNP and GA3 pre-treatment increased seed germination rate, germination index, weights and lengths of coleoptile and radicle, while they decreased mean germination time and weight of seeds germinating under low temperature. Exogenous NO and GA3...... by exogenous NO and GA3 as a result of improved seed germination and maintenance of better reactive oxygen species homeostasis in seedling growing under chilling temperatures. It is indicated that exogenous NO was more effective than GA3 in alleviating chilling stress during seed germination and seedling...

  18. Circulating nitric oxide metabolites and cardiovascular changes in the turtle Trachemys scripta during normoxia, anoxia and reoxygenation

    DEFF Research Database (Denmark)

    Jacobsen, Søren B.; Hansen, Marie Niemann; Jensen, Frank Bo

    2012-01-01

    Turtles of the genus Trachemys show a remarkable ability to survive prolonged anoxia. This is achieved by a strong metabolic depression, redistribution of blood flow and high levels of antioxidant defence. To understand whether nitric oxide (NO), a major regulator of vasodilatation and oxygen...... consumption, may be involved in the adaptive response of Trachemys to anoxia, we measured NO metabolites (nitrite, S-nitroso, Fe-nitrosyl and N-nitroso compounds) in the plasma and red blood cells of venous and arterial blood of Trachemys scripta turtles during normoxia and after anoxia (3 h......-nitroso compounds were present at high micromolar levels under normoxia and increased further after anoxia and reoxygenation, suggesting NO generation from nitrite catalysed by deoxygenated haemoglobin, which in turtle had a higher nitrite reductase activity than in hypoxia-intolerant species. Taken together...

  19. Vascular Kinin B1 and B2 Receptors Determine Endothelial Dysfunction through Neuronal Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    Luciano Dos Santos A. Capettini

    2017-04-01

    Full Text Available B1- and B2-kinin receptors are G protein-coupled receptors that play an important role in the vascular function. Therefore, the present study was designed to evaluate the participation of kinin receptors in the acetylcholine (ACh-induced vascular relaxation, focusing on the protein-protein interaction involving kinin receptors with endothelial and neuronal nitric oxide synthases (eNOS and nNOS. Vascular reactivity, nitric oxide (NO· and reactive oxygen species (ROS generation, co-immunoprecipitation were assessed in thoracic aorta from male wild-type (WT, B1- (B1R−/−, B2- (B2R−/− knockout mice. Some vascular reactivity experiments were also performed in a double kinin receptors knockout mice (B1B2R−/−. For pharmacological studies, selective B1- and B2-kinin receptors antagonists, NOS inhibitors and superoxide dismutase (SOD mimetic were used. First, we show that B1- and B2-kinin receptors form heteromers with nNOS and eNOS in thoracic aorta. To investigate the functionality of these protein-protein interactions, we took advantage of pharmacological tools and knockout mice. Importantly, our results show that kinin receptors regulate ACh-induced relaxation via nNOS signaling in thoracic aorta with no changes in NO· donor-induced relaxation. Interestingly, B1B2R−/− presented similar level of vascular dysfunction as found in B1R−/− or B2R−/− mice. In accordance, aortic rings from B1R−/− or B2R−/− mice exhibit decreased NO· bioavailability and increased superoxide generation compared to WT mice, suggesting the involvement of excessive ROS generation in the endothelial dysfunction of B1R−/− and B2R−/− mice. Alongside, we show that impaired endothelial vasorelaxation induced by ACh in B1R−/− or B2R−/− mice was rescued by the SOD mimetic compound. Taken together, our findings show that B1- and B2-kinin receptors regulate the endothelium-dependent vasodilation of ACh through nNOS activity and indicate

  20. Validation Testing of the Nitric Acid Dissolution Step Within the K Basin Sludge Pretreatment Process

    International Nuclear Information System (INIS)

    AJ Schmidt; CH Delegard; KL Silvers; PR Bredt; CD Carlson; EW Hoppe; JC Hayes; DE Rinehart; SR Gano; BM Thornton

    1999-01-01

    The work described in this report involved comprehensive bench-scale testing of nitric acid (HNO 3 ) dissolution of actual sludge materials from the Hanford K East (KE) Basin to confirm the baseline chemical pretreatment process. In addition, process monitoring and material balance information was collected to support the development and refinement of process flow diagrams. The testing was performed by Pacific Northwest National Laboratory (PNNL)for the US Department of Energy's Office of Spent Fuel Stabilization (EM-67) and Numatec Hanford Corporation (NHC) to assist in the development of the K Basin Sludge Pretreatment Process. The baseline chemical pretreatment process for K Basin sludge is nitric acid dissolution of all particulate material passing a 1/4-in. screen. The acid-insoluble fraction (residual solids) will be stabilized (possibly by chemical leaching/rinsing and grouting), packaged, and transferred to the Hanford Environmental Restoration Disposal Facility (ERDF). The liquid fraction is to be diluted with depleted uranium for uranium criticality safety and iron nitrate for plutonium criticality safety, and neutralized with sodium hydroxide. The liquid fraction and associated precipitates are to be stored in the Hanford Tank Waste Remediation Systems (TWRS) pending vitrification. It is expected that most of the polychlorinated biphenyls (PCBs), associated with some K Basin sludges, will remain with the residual solids for ultimate disposal to ERDF. Filtration and precipitation during the neutralization step will further remove trace quantities of PCBs within the liquid fraction. The purpose of the work discussed in this report was to examine the dissolution behavior of actual KE Basin sludge materials at baseline flowsheet conditions and validate the.dissolution process step through bench-scale testing. The progress of the dissolution was evaluated by measuring the solution electrical conductivity and concentrations of key species in the dissolver

  1. Validation Testing of the Nitric Acid Dissolution Step Within the K Basin Sludge Pretreatment Process

    Energy Technology Data Exchange (ETDEWEB)

    AJ Schmidt; CH Delegard; KL Silvers; PR Bredt; CD Carlson; EW Hoppe; JC Hayes; DE Rinehart; SR Gano; BM Thornton

    1999-03-24

    The work described in this report involved comprehensive bench-scale testing of nitric acid (HNO{sub 3}) dissolution of actual sludge materials from the Hanford K East (KE) Basin to confirm the baseline chemical pretreatment process. In addition, process monitoring and material balance information was collected to support the development and refinement of process flow diagrams. The testing was performed by Pacific Northwest National Laboratory (PNNL)for the US Department of Energy's Office of Spent Fuel Stabilization (EM-67) and Numatec Hanford Corporation (NHC) to assist in the development of the K Basin Sludge Pretreatment Process. The baseline chemical pretreatment process for K Basin sludge is nitric acid dissolution of all particulate material passing a 1/4-in. screen. The acid-insoluble fraction (residual solids) will be stabilized (possibly by chemical leaching/rinsing and grouting), packaged, and transferred to the Hanford Environmental Restoration Disposal Facility (ERDF). The liquid fraction is to be diluted with depleted uranium for uranium criticality safety and iron nitrate for plutonium criticality safety, and neutralized with sodium hydroxide. The liquid fraction and associated precipitates are to be stored in the Hanford Tank Waste Remediation Systems (TWRS) pending vitrification. It is expected that most of the polychlorinated biphenyls (PCBs), associated with some K Basin sludges, will remain with the residual solids for ultimate disposal to ERDF. Filtration and precipitation during the neutralization step will further remove trace quantities of PCBs within the liquid fraction. The purpose of the work discussed in this report was to examine the dissolution behavior of actual KE Basin sludge materials at baseline flowsheet conditions and validate the.dissolution process step through bench-scale testing. The progress of the dissolution was evaluated by measuring the solution electrical conductivity and concentrations of key species in the

  2. Normalization of hemoglobin-based oxygen carrier-201 induced vasoconstriction: targeting nitric oxide and endothelin.

    Science.gov (United States)

    Taverne, Yannick J; de Wijs-Meijler, Daphne; Te Lintel Hekkert, Maaike; Moon-Massat, Paula F; Dubé, Gregory P; Duncker, Dirk J; Merkus, Daphne

    2017-05-01

    Hemoglobin-based oxygen carrier (HBOC)-201 is a cell-free modified hemoglobin solution potentially facilitating oxygen uptake and delivery in cardiovascular disorders and hemorrhagic shock. Clinical use has been hampered by vasoconstriction in the systemic and pulmonary beds. Therefore, we aimed to 1 ) determine the possibility of counteracting HBOC-201-induced pressor effects with either adenosine (ADO) or nitroglycerin (NTG); 2 ) assess the potential roles of nitric oxide (NO) scavenging, reactive oxygen species (ROS), and endothelin (ET) in mediating the observed vasoconstriction; and 3 ) compare these effects in resting and exercising swine. Chronically instrumented swine were studied at rest and during exercise after administration of HBOC-201 alone or in combination with ADO. The role of NO was assessed by supplementation with NTG or administration of the eNOS inhibitor N ω -nitro-l-arginine. Alternative vasoactive pathways were investigated via intravenous administration of the ET A /ET B receptor blocker tezosentan or a mixture of ROS scavengers. The systemic and to a lesser extent the pulmonary pressor effects of HBOC-201 could be counteracted by ADO; however, dosage titration was very important to avoid systemic hypotension. Similarly, supplementation of NO with NTG negated the pressor effects but also required titration of the dose. The pressor response to HBOC-201 was reduced after eNOS inhibition and abolished by simultaneous ET A /ET B receptor blockade, while ROS scavenging had no effect. In conclusion, the pressor response to HBOC-201 is mediated by vasoconstriction due to NO scavenging and production of ET. Further research should explore the effect of longer-acting ET receptor blockers to counteract the side effect of hemoglobin-based oxygen carriers. NEW & NOTEWORTHY Hemoglobin-based oxygen carrier (HBOC)-201 can disrupt hemodynamic homeostasis, mimicking some aspects of endothelial dysfunction, resulting in elevated systemic and pulmonary blood

  3. Behavior of silicon in nitric media. Application to uranium silicides fuels reprocessing; Comportement du silicium en milieu nitrique. Application au retraitement des combustibles siliciures d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Cheroux, L

    2001-07-01

    Uranium silicides are used in some research reactors. Reprocessing them is a solution for their cycle end. A list of reprocessing scenarios has been set the most realistic being a nitric dissolution close to the classic spent fuel reprocessing. This uranium silicide fuel contains a lot of silicon and few things are known about polymerization of silicic acid in concentrated nitric acid. The study of this polymerization allows to point out the main parameters: acidity, temperature, silicon concentration. The presence of aluminum seems to speed up heavily the polymerization. It has been impossible to find an analytical technique smart and fast enough to characterize the first steps of silicic acid polymerization. However the action of silicic species on emulsions stabilization formed by mixing them with an organic phase containing TBP has been studied, Silicon slows down the phase separation by means of oligomeric species forming complex with TBP. The existence of these intermediate species is short and heating can avoid any stabilization. When non irradiated uranium silicide fuel is attacked by a nitric solution, aluminum and uranium are quickly dissolved whereas silicon mainly stands in solid state. That builds a gangue of hydrated silica around the uranium silicide particulates without preventing uranium dissolution. A small part of silicon passes into the solution and polymerize towards the highly poly-condensed forms, just 2% of initial silicon is still in molecular form at the end of the dissolution. A thermal treatment of the fuel element, by forming inter-metallic phases U-Al-Si, allows the whole silicon to pass into the solution and next to precipitate. The behavior of silicon in spent fuels should be between these two situations. (author)

  4. Nitric oxide treatment for the control of reverse osmosis membrane biofouling.

    Science.gov (United States)

    Barnes, Robert J; Low, Jiun Hui; Bandi, Ratnaharika R; Tay, Martin; Chua, Felicia; Aung, Theingi; Fane, Anthony G; Kjelleberg, Staffan; Rice, Scott A

    2015-04-01

    Biofouling remains a key challenge for membrane-based water treatment systems. This study investigated the dispersal potential of the nitric oxide (NO) donor compound, PROLI NONOate, on single- and mixed-species biofilms formed by bacteria isolated from industrial membrane bioreactor and reverse osmosis (RO) membranes. The potential of PROLI NONOate to control RO membrane biofouling was also examined. Confocal microscopy revealed that PROLI NONOate exposure induced biofilm dispersal in all but two of the bacteria tested and successfully dispersed mixed-species biofilms. The addition of 40 μM PROLI NONOate at 24-h intervals to a laboratory-scale RO system led to a 92% reduction in the rate of biofouling (pressure rise over a given period) by a bacterial community cultured from an industrial RO membrane. Confocal microscopy and extracellular polymeric substances (EPS) extraction revealed that PROLI NONOate treatment led to a 48% reduction in polysaccharides, a 66% reduction in proteins, and a 29% reduction in microbial cells compared to the untreated control. A reduction in biofilm surface coverage (59% compared to 98%, treated compared to control) and average thickness (20 μm compared to 26 μm, treated compared to control) was also observed. The addition of PROLI NONOate led to a 22% increase in the time required for the RO module to reach its maximum transmembrane pressure (TMP), further indicating that NO treatment delayed fouling. Pyrosequencing analysis revealed that the NO treatment did not significantly alter the microbial community composition of the membrane biofilm. These results present strong evidence for the application of PROLI NONOate for prevention of RO biofouling. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. Nitrate reduction to nitrite, nitric oxide and ammonia by gut bacteria under physiological conditions.

    Directory of Open Access Journals (Sweden)

    Mauro Tiso

    Full Text Available The biological nitrogen cycle involves step-wise reduction of nitrogen oxides to ammonium salts and oxidation of ammonia back to nitrites and nitrates by plants and bacteria. Neither process has been thought to have relevance to mammalian physiology; however in recent years the salivary bacterial reduction of nitrate to nitrite has been recognized as an important metabolic conversion in humans. Several enteric bacteria have also shown the ability of catalytic reduction of nitrate to ammonia via nitrite during dissimilatory respiration; however, the importance of this pathway in bacterial species colonizing the human intestine has been little studied. We measured nitrite, nitric oxide (NO and ammonia formation in cultures of Escherichia coli, Lactobacillus and Bifidobacterium species grown at different sodium nitrate concentrations and oxygen levels. We found that the presence of 5 mM nitrate provided a growth benefit and induced both nitrite and ammonia generation in E.coli and L.plantarum bacteria grown at oxygen concentrations compatible with the content in the gastrointestinal tract. Nitrite and ammonia accumulated in the growth medium when at least 2.5 mM nitrate was present. Time-course curves suggest that nitrate is first converted to nitrite and subsequently to ammonia. Strains of L.rhamnosus, L.acidophilus and B.longum infantis grown with nitrate produced minor changes in nitrite or ammonia levels in the cultures. However, when supplied with exogenous nitrite, NO gas was readily produced independently of added nitrate. Bacterial production of lactic acid causes medium acidification that in turn generates NO by non-enzymatic nitrite reduction. In contrast, nitrite was converted to NO by E.coli cultures even at neutral pH. We suggest that the bacterial nitrate reduction to ammonia, as well as the related NO formation in the gut, could be an important aspect of the overall mammalian nitrate/nitrite/NO metabolism and is yet another way in

  6. ABA crosstalk with ethylene and nitric oxide in seed dormancy and germination

    Science.gov (United States)

    Arc, Erwann; Sechet, Julien; Corbineau, Françoise; Rajjou, Loïc; Marion-Poll, Annie

    2013-01-01

    Dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. It has been clearly demonstrated that dormancy is induced by abscisic acid (ABA) during seed development on the mother plant. After seed dispersal, germination is preceded by a decline in ABA in imbibed seeds, which results from ABA catabolism through 8′-hydroxylation. The hormonal balance between ABA and gibberellins (GAs) has been shown to act as an integrator of environmental cues to maintain dormancy or activate germination. The interplay of ABA with other endogenous signals is however less documented. In numerous species, ethylene counteracts ABA signaling pathways and induces germination. In Brassicaceae seeds, ethylene prevents the inhibitory effects of ABA on endosperm cap weakening, thereby facilitating endosperm rupture and radicle emergence. Moreover, enhanced seed dormancy in Arabidopsis ethylene-insensitive mutants results from greater ABA sensitivity. Conversely, ABA limits ethylene action by down-regulating its biosynthesis. Nitric oxide (NO) has been proposed as a common actor in the ABA and ethylene crosstalk in seed. Indeed, convergent evidence indicates that NO is produced rapidly after seed imbibition and promotes germination by inducing the expression of the ABA 8′-hydroxylase gene, CYP707A2, and stimulating ethylene production. The role of NO and other nitrogen-containing compounds, such as nitrate, in seed dormancy breakage and germination stimulation has been reported in several species. This review will describe our current knowledge of ABA crosstalk with ethylene and NO, both volatile compounds that have been shown to counteract ABA action in seeds and to improve dormancy release and germination. PMID:23531630

  7. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals.

    Science.gov (United States)

    Fago, Angela; Parraga, Daniel Garcia; Petersen, Elin E; Kristensen, Niels; Giouri, Lea; Jensen, Frank B

    2017-03-01

    The ability of marine mammals to hunt prey at depth is known to rely on enhanced oxygen stores and on selective distribution of blood flow, but the molecular mechanisms regulating blood flow and oxygen transport remain unresolved. To investigate the molecular mechanisms that may be important in regulating blood flow, we measured concentration of nitrite and S-nitrosothiols (SNO), two metabolites of the vasodilator nitric oxide (NO), in the blood of 5 species of marine mammals differing in their dive duration: bottlenose dolphin, South American sea lion, harbor seal, walrus and beluga whale. We also examined oxygen affinity, sensitivity to 2,3-diphosphoglycerate (DPG) and nitrite reductase activity of the hemoglobin (Hb) to search for possible adaptive variations in these functional properties. We found levels of plasma and red blood cells nitrite similar to those reported for terrestrial mammals, but unusually high concentrations of red blood cell SNO in bottlenose dolphin, walrus and beluga whale, suggesting enhanced SNO-dependent signaling in these species. Purified Hbs showed similar functional properties in terms of oxygen affinity and sensitivity to DPG, indicating that reported large variations in blood oxygen affinity among diving mammals likely derive from phenotypic variations in red blood cell DPG levels. The nitrite reductase activities of the Hbs were overall slightly higher than that of human Hb, with the Hb of beluga whale, capable of longest dives, having the highest activity. Taken together, these results underscore adaptive variations in circulatory NO metabolism in diving mammals but not in the oxygenation properties of the Hb. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Evaluation of the effects of nitric oxide-releasing nanoparticles on plants

    Science.gov (United States)

    Pereira, A. E. S.; Narciso, A. M.; Seabra, A. B.; Fraceto, L. F.

    2015-05-01

    Nowadays, there are several commercially available products containing nanostructured materials. Meanwhile, despite the many benefits that can be obtained from nanotechnology, it is still necessary to understand the mechanisms in which nanomaterials interact with the environment, and to obtain information concerning their possible toxic effects. In agriculture, nanotechnology has been used in different applications, such as nanosensors to detect pathogens, nanoparticles as controlled release systems for pesticides, and biofilms to deliver nutrients to plants and to protect food products against degradation. Moreover, plants can be used as models to study the toxicity of nanoparticles. Indeed, phytotoxicity assays are required to identify possible negative effects of nanostructured systems, prior to their implementation in agriculture. Nitric oxide (NO) plays a key role in plant growth and defense, and recently, several papers described the beneficial effects due to application of exogenous NO donors in plants. The tripeptide glutathione (GSH) is an important anti-oxidant molecule and is the precursor of the NO donor, S-nitrosoglutathione (GSNO). In this context, the present work investigates the effects of different concentrations of alginate/chitosan nanoparticles, containing either GSH or GSNO, on the development of two test species (Zea mays and Glycine sp.). The results showed that the alginate/chitosan nanoparticles present a size average range from 300 to 550 nm with a polydispersity index of 0.35, and encapsulation efficiency of GSH between 45 - 56%. The NO release kinetics from the alginate/chitosan nanoparticles containing GSNO showed sustained and controlled NO release over several hours. Plant assays showed that at the concentrations tested (1, 5 and 10 mM of GSH or GSNO), polymeric nanoparticles showed no significant inhibitory effects on the development of the species Zea mays and Glycine sp., considering the variables shoot height, root length, and

  9. Evaluation of the effects of nitric oxide-releasing nanoparticles on plants

    International Nuclear Information System (INIS)

    Pereira, A E S; Fraceto, L F; Narciso, A M; Seabra, A B

    2015-01-01

    Nowadays, there are several commercially available products containing nanostructured materials. Meanwhile, despite the many benefits that can be obtained from nanotechnology, it is still necessary to understand the mechanisms in which nanomaterials interact with the environment, and to obtain information concerning their possible toxic effects. In agriculture, nanotechnology has been used in different applications, such as nanosensors to detect pathogens, nanoparticles as controlled release systems for pesticides, and biofilms to deliver nutrients to plants and to protect food products against degradation. Moreover, plants can be used as models to study the toxicity of nanoparticles. Indeed, phytotoxicity assays are required to identify possible negative effects of nanostructured systems, prior to their implementation in agriculture. Nitric oxide (NO) plays a key role in plant growth and defense, and recently, several papers described the beneficial effects due to application of exogenous NO donors in plants. The tripeptide glutathione (GSH) is an important anti-oxidant molecule and is the precursor of the NO donor, S-nitrosoglutathione (GSNO). In this context, the present work investigates the effects of different concentrations of alginate/chitosan nanoparticles, containing either GSH or GSNO, on the development of two test species (Zea mays and Glycine sp.). The results showed that the alginate/chitosan nanoparticles present a size average range from 300 to 550 nm with a polydispersity index of 0.35, and encapsulation efficiency of GSH between 45 - 56%. The NO release kinetics from the alginate/chitosan nanoparticles containing GSNO showed sustained and controlled NO release over several hours. Plant assays showed that at the concentrations tested (1, 5 and 10 mM of GSH or GSNO), polymeric nanoparticles showed no significant inhibitory effects on the development of the species Zea mays and Glycine sp., considering the variables shoot height, root length, and

  10. Nitric oxide levels are not changed in saliva of patients infected with hepatitis C virus

    OpenAIRE

    Tavares, Fernando N.; Gonçalves, Patricia L.; Porto, Simone A.C.; Pereira, Fausto E.L.; Ribeiro-Rodrigues, Rodrigo

    2005-01-01

    The aim of this investigation was to determine nitric oxide metabolite levels in saliva samples from hepatitis C virus-positive patients in an attempt to test the hypothesis if increased levels of nitric oxide metabolites correlates with the presence of HCV-RNA in saliva. Saliva of 39 HCV-positive patients and 13 HCV-negative patients, without clinical or laboratorial evidence of liver disease were tested for nitric oxide metabolites. HCV-RNA was detected in serum and saliva by a RT-PCR metho...

  11. The reversible reaction kinetics of neptunium with nitrous and nitric acids

    International Nuclear Information System (INIS)

    Hu Zhang; Zhan-Yuan Liu; Li Li; He Yang; Guo-An Ye; Xian-Ming Zhou; Ri-teng Wang

    2016-01-01

    In order to understand the equilibrium state, conversion process and mechanism of Np(V)/Np(VI) in nitric acid solution, the redox kinetics of neptunium with nitrous and nitric acids was studied spectrophotometrically by an nonlinear fitting method. The rate equation of the redox reaction was acquired. Apparent activation energy of forward reaction and reverse reaction are approximately the same of 80 kJ/mol. Varying the concentrations of nitric and nitrous acids will change the reaction rate of forward and reverse reaction in different degrees. As a result, the equilibrium state of Np(V)/Np(VI) is altered, but it is not influenced by temperature. (author)

  12. Dual inhibition of nitric oxide and prostaglandin E-2 production by polysubstituted 2-aminopyrimidines

    Czech Academy of Sciences Publication Activity Database

    Zídek, Z.; Kverka, Miloslav; Dusilová, Adéla; Kmoníčková, E.; Jansa, P.

    2016-01-01

    Roč. 57, July 1 (2016), s. 48-56 ISSN 1089-8603 Institutional support: RVO:61388971 Keywords : Pyrimidines * Nitric oxide * Prostaglandin E-2 Subject RIV: EE - Microbiology, Virology Impact factor: 4.181, year: 2016

  13. MLS/Aura L2 Nitric Acid (HNO3) Mixing Ratio V003

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  14. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V004

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  15. MLS/Aura L2 Nitric Acid (HNO3) Mixing Ratio V002

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  16. LBA-ECO ND-07 Nitric Oxide Flux from Cerrado Soils, Brasilia, Brazil: 2004

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports the results of soil nitric oxide (NO) flux, soil moisture, and soil nitrate (NO3) and ammonium (NH4) concentration measurements on Cerrado...

  17. LBA-ECO ND-07 Nitric Oxide Flux from Cerrado Soils, Brasilia, Brazil: 2004

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports the results of soil nitric oxide (NO) flux, soil moisture, and soil nitrate (NO3) and ammonium (NH4) concentration measurements on...

  18. Arginase strongly impairs neuronal nitric oxide-mediated airway smooth muscle relaxation in allergic asthma

    NARCIS (Netherlands)

    Maarsingh, H; Leusink, J; Bos, IST; Zaagsma, J; Meurs, H

    2006-01-01

    Background: Using guinea pig tracheal preparations, we have recently shown that endogenous arginase activity attenuates inhibitory nonadrenergic noncholinergic (iNANC) nerve-mediated airway smooth muscle relaxation by reducing nitric oxide (NO) production - due to competition with neuronal

  19. Hypotensive effect of hydroxylamine, an endogenous nitric oxide donor and SSAO inhibitor.

    Science.gov (United States)

    Vidrio, H; Medina, M

    2007-01-01

    The endogenous compound hydroxylamine relaxes vascular smooth muscle in vitro, apparently through conversion to the vasodilator factor nitric oxide, but its effect on blood pressure has not been characterized. We found that in the anesthetized rat the amine elicits dose-related hypotension when administered by continuous iv infusion. In experiments designed to explore the mechanism of this effect, hydroxylamine was compared with the nitric oxide donor nitroprusside and the direct-acting vasodilator hydralazine, using pretreatments known to modify diverse mechanisms of vasodilation. Hydroxylamine hypotension was enhanced by the SSAO inhibitor isoniazid and the SSAO substrate methylamine, a pattern shared by hydralazine. Responses were blocked by the guanylate cyclase inhibitor methylene blue and were increased by the nitric oxide synthase inhibitor L-NAME, a pattern shared by nitroprusside. It was concluded that hydroxylamine exerts hypotension partly through conversion to nitric oxide and partly by a "hydralazine-like" mechanism involving SSAO inhibition.

  20. HIRDLS/Aura Level 3 Nitric Acid (HNO3) Zonal Fourier Coefficients V007

    Data.gov (United States)

    National Aeronautics and Space Administration — The "HIRDLS/Aura Level 3 Nitric Acid (HNO3) Zonal Fourier Coefficients" version 7 data product (H3ZFCHNO3) contains the entire mission (~3 years) of HIRDLS data...

  1. Calcium-activated potassium channels - a therapeutic target for modulating nitric oxide in cardiovascular disease?

    DEFF Research Database (Denmark)

    Dalsgaard, Thomas; Kroigaard, Christel; Simonsen, Ulf

    2010-01-01

    IMPORTANCE OF THE FIELD: Cardiovascular risk factors are often associated with endothelial dysfunction, which is also prognostic for occurrence of cardiovascular events. Endothelial dysfunction is reflected by blunted vasodilatation and reduced nitric oxide (NO) bioavailability. Endothelium...

  2. Involvement of nitric oxide in human transient lower esophageal sphincter relaxations and esophageal primary peristalsis

    NARCIS (Netherlands)

    Hirsch, D. P.; Holloway, R. H.; Tytgat, G. N.; Boeckxstaens, G. E.

    1998-01-01

    BACKGROUND & AIMS: Nitric oxide (NO) is well accepted as an inhibitory neurotransmitter in the gastrointestinal tract; however, its role in the triggering of transient lower esophageal sphincter relaxations (TLESRs) in humans remains to be determined. Therefore, the effect of

  3. Arginase attenuates inhibitory nonadrenergic noncholinergic nerve-induced nitric oxide generation and airway smooth muscle relaxation

    NARCIS (Netherlands)

    Maarsingh, H; Tio, MA; Zaagsma, J; Meurs, H

    2005-01-01

    Background: Recent evidence suggests that endogenous arginase activity potentiates airway responsiveness to methacholine by attenuation of agonist-induced nitric oxide (NO) production, presumably by competition with epithelial constitutive NO synthase for the common substrate, L-arginine. Using

  4. Critical evaluation of pressurized microwave-assisted digestion efficiency using nitric acid oxidizing systems (M7)

    International Nuclear Information System (INIS)

    Matusiewicz, H.

    2002-01-01

    Full text: The possibilities of enhancement of a medium-pressure microwave-assisted digestion system for sample preparation in trace element analysis of biological material was investigated. Based on optimal digestion conditions for oxidizing systems with nitric acid, different digestion procedures were examined to minimize residual carbon. The substitution of nitric acid and the addition of hydrogen peroxide and ozone to nitric acid was evaluated. The residual carbon content of the digestate was determined coulometrically. Addition of hydrogen peroxide during organic oxidation reactions does not lower the resolved carbon in the solution. Ozone was tested as an additional, potentially non-contaminating, digestion/oxidation system to the nitric acid used in the sample preparation method. (author)

  5. The effect of inhaled nitric oxide in acute respiratory distress syndrome in children and adults

    DEFF Research Database (Denmark)

    Karam, O; Gebistorf, F; Wetterslev, J

    2017-01-01

    on mortality in adults and children with acute respiratory distress syndrome. We included all randomised, controlled trials, irrespective of date of publication, blinding status, outcomes reported or language. Our primary outcome measure was all-cause mortality. We performed several subgroup and sensitivity......Acute respiratory distress syndrome is associated with high mortality and morbidity. Inhaled nitric oxide has been used to improve oxygenation but its role remains controversial. Our primary objective in this systematic review was to examine the effects of inhaled nitric oxide administration......% CI) 1.59 (1.17-2.16)) with inhaled nitric oxide. In conclusion, there is insufficient evidence to support inhaled nitric oxide in any category of critically ill patients with acute respiratory distress syndrome despite a transient improvement in oxygenation, since mortality is not reduced and it may...

  6. Nitric oxide mediates insect cellular immunity via phospholipase A2 activation

    Science.gov (United States)

    After infection or invasion is recognized, biochemical mediators act in signaling insect immune functions. These include biogenic amines, insect cytokines, eicosanoids and nitric oxide (NO). Treating insects or isolated hemocyte populations with different mediators often leads to similar results. Se...

  7. Absorption of nitric oxide into aqueous solutions of ferrous chelates accompanied by instantaneous reaction

    NARCIS (Netherlands)

    Demmink, J.F; vanGils, I.C.F.; Beenackers, A.A C M

    1997-01-01

    The absorption of nitric oxide (NO) into aqueous solutions of ferrous chelates of nitrilotriacetic acid (NTA), ethylene diaminetetraacetic acid (EDTA), hydroxyethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA) was studied in a stirred cell reactor. Experimental

  8. The Validity of Exhaled Nitric Oxide (NO) in Breath Condensate in ...

    African Journals Online (AJOL)

    The Validity of Exhaled Nitric Oxide (NO) in Breath Condensate in the Evaluation of Controlled Asthma. Ahmed Elsayed Elhefny, Sahar Mohammad Mourad, Tamer Saeed Morsy, Maher Abdelnbi Kamel, Haydi Moustafa Mohamed ...

  9. Nucleation of nitric acid hydrates in polar stratospheric clouds by meteoric material

    Science.gov (United States)

    James, Alexander D.; Brooke, James S. A.; Mangan, Thomas P.; Whale, Thomas F.; Plane, John M. C.; Murray, Benjamin J.

    2018-04-01

    Heterogeneous nucleation of crystalline nitric acid hydrates in polar stratospheric clouds (PSCs) enhances ozone depletion. However, the identity and mode of action of the particles responsible for nucleation remains unknown. It has been suggested that meteoric material may trigger nucleation of nitric acid trihydrate (NAT, or other nitric acid phases), but this has never been quantitatively demonstrated in the laboratory. Meteoric material is present in two forms in the stratosphere: smoke that results from the ablation and re-condensation of vapours, and fragments that result from the break-up of meteoroids entering the atmosphere. Here we show that analogues of both materials have a capacity to nucleate nitric acid hydrates. In combination with estimates from a global model of the amount of meteoric smoke and fragments in the polar stratosphere we show that meteoric material probably accounts for NAT observations in early season polar stratospheric clouds in the absence of water ice.

  10. The radiolytic formation of nitric acid in argon/air/water systems

    International Nuclear Information System (INIS)

    May, R.; Stinchcombe, D.; White, H.P.

    1992-01-01

    The extent of nitric acid formation in the γ-radiolysis of argon/air/water mixtures has been assessed. The yields of nitric acid are found to increase as water vapour pressure is increased but are lower in the presence of a discrete water phase. G values for the formation of nitric acid from argon/air mixtures based on energy absorbed in the air are increased in the presence of argon but the yields in an atmosphere of argon containing small amounts of moist air are smaller than from an atmosphere of moist air alone. The G value for nitric acid formation from pure air in the presence of a distinct water phase is 2, based on energy absorbed in the air. (author)

  11. Nitric oxide-cytokinin interplay influences selenite sensitivity in Arabidopsis.

    Science.gov (United States)

    Lehotai, Nóra; Feigl, Gábor; Koós, Ágnes; Molnár, Árpád; Ördög, Attila; Pető, Andrea; Erdei, László; Kolbert, Zsuzsanna

    2016-10-01

    Selenite oppositely modifies cytokinin and nitric oxide metabolism in Arabidopsis organs. A mutually negative interplay between the molecules exists in selenite-exposed roots; and their overproduction causes selenite insensitivity. Selenium-induced phytotoxicity is accompanied by developmental alterations such as primary root (PR) shortening. Growth changes are provoked by the modulation of hormone status and signalling. Cytokinin (CK) cooperates with the nitric oxide (NO) in many aspects of plant development; however, their interaction under abiotic stress has not been examined. Selenite inhibited the growth of Arabidopsis seedlings and reduced root meristem size through cell division arrest. The CK-dependent pARR5::GUS activity revealed the intensification of CK signalling in the PR tip, which may be partly responsible for the root meristem shortening. The selenite-induced alterations in the in situ expressions of cytokinin oxidases (AtCKX4::GUS, AtCKX5::GUS) are associated with selenite-triggered changes of CK signalling. In wild-type (WT) and NO-deficient nia1nia2 root, selenite led to the diminution of NO content, but CK overproducer ipt-161 and -deficient 35S:CKX2 roots did not show NO decrease. Exogenous NO (S-nitroso-N-acetyl-DL-penicillamine, SNAP) reduced the pARR5::GFP and pTCS::GFP expressions. Roots of the 35S:CKX and cyr1 plants suffered more severe selenite-triggered viability loss than the WT, while in ipt-161 and gsnor1-3 no obvious viability decrease was observed. Exogenous NO ameliorated viability loss, but benzyladenine intensified it. Based on the results, selenite impacts development by oppositely modifying CK signalling and NO level. In the root system, CK signalling intensifies which possibly contributes to the nitrate reductase-independent NO diminution. A mutually negative CK-NO interplay exists in selenite-exposed roots; however, overproduction of both molecules worsens selenite sensing. Hereby, we suggest novel regulatory interplay and

  12. Nitric oxide emissions from soils amended with municipal waste biosolids

    International Nuclear Information System (INIS)

    Roelle, P.A.; Aneja, V.P.

    2002-01-01

    Land spreading nitrogen-rich municipal waste biosolids (NO 3 - -N -1 dry weight, NH 3 -N∼23,080mg Nkg -1 dry weight, Total Kjeldahl N∼41,700mg Nkg -1 dry weight) to human food and non-food chain land is a practice followed throughout the US. This practice may lead to the recovery and utilization of the nitrogen by vegetation, but it may also lead to emissions of biogenic nitric oxide (NO), which may enhance ozone pollution in the lower levels of the troposphere. Recent global estimates of biogenic NO emissions from soils are cited in the literature, which are based on field measurements of NO emissions from various agricultural and non-agricultural fields. However, biogenic emissions of NO from soils amended with biosolids are lacking. Utilizing a state-of-the-art mobile laboratory and a dynamic flow-through chamber system, in-situ concentrations of nitric oxide (NO) were measured during the spring/summer of 1999 and winter/spring of 2000 from an agricultural soil which is routinely amended with municipal waste biosolids. The average NO flux for the late spring/summer time period (10 June 1999-5 August 1999) was 69.4±34.9ngNm -2 s -1 . Biosolids were applied during September 1999 and the field site was sampled again during winter/spring 2000 (28 February 2000-9 March 2000), during which the average flux was 3.6±l.7ngNm -2 s -1 . The same field site was sampled again in late spring (2-9 June 2000) and the average flux was 64.8±41.0ng Nm -2 s -1 . An observationally based model, developed as part of this study, found that summer accounted for 60% of the yearly emission while fall, winter and spring accounted for 20%, 4% and 16% respectively. Field experiments were conducted which indicated that the application of biosolids increases the emissions of NO and that techniques to estimate biogenic NO emissions would, on a yearly average, underestimate the NO flux from this field by a factor of 26. Soil temperature and % water filled pore space (%WFPS) were observed

  13. (Annonaceae) species

    African Journals Online (AJOL)

    Aghomotsegin

    2016-03-09

    Mar 9, 2016 ... 2Bioactivity Programme, Natural Products Division, Forest Research Institute Malaysia (FRIM), 52109 Kepong, Selangor. Darul Ehsan, Malaysia. ... The genus Xylopia comprises about 170 species and they are widely .... American Type Culture Collection (ATCC) while VRSA156 and. VISA24 were lab ...

  14. Emissions of gaseous nitrogen species from manure management

    DEFF Research Database (Denmark)

    Dämmgen, Ulrich; Hutchings, Nick

    2008-01-01

    A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows...... in the husbandry of mammals are depicted, the methodology is considered a Tier 3 approach in IPCC terminology or a detailed methodology in UN ECE terminology. The importance of accounting for all N species is illustrated by comparing emission estimates obtained using this approach with those obtained from...

  15. Endothelial nitric oxide synthase gene polymorphisms (G894T) in diabetes mellitus in Egypt

    OpenAIRE

    El-baz1 ; Farouk2; Tag Eldin2; Ezat2

    2010-01-01

    Objective: Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes. Genetic predisposition has been implicated in DN. The eNOS protein synthesizes nitric oxide constitutively via a reaction including the conversion of L-arginine to L-citrulline, which involves the transfer of five electrons provided by nicotinamide adenine dinucleotide phosphate The aim of this study is to evaluate the association of G894T polymorphisms of endothelial nitric oxide synthase(eNOS) ...

  16. A bibliographical review on the radiolysis of uranyl nitrate solutions in nitric acid medium

    International Nuclear Information System (INIS)

    Siri, Sandra; Mondino, Angel V.

    2004-01-01

    A bibliographical study on the effects of ionizing radiation on uranyl nitrate solutions in nitric acid medium was performed, and the state of knowledge on this subject is presented. The main experimental and theoretical results on water, nitric acid and uranium solutions radiolysis are reviewed and critically evaluated. This paper provides a collection of references as an aid to the development of practical applications, and to stimulate new research on fundamental processes in these systems. (author) [es

  17. Continuous electrochemical monitoring of nitric oxide production in murine macrophage cell line RAW 264.7

    Czech Academy of Sciences Publication Activity Database

    Pekarová, Michaela; Králová, Jana; Kubala, Lukáš; Číž, Milan; Lojek, Antonín; Gregor, Č.; Hrbáč, J.

    2009-01-01

    Roč. 394, č. 5 (2009), s. 1497-1504 ISSN 1618-2642 R&D Projects: GA AV ČR(CZ) 1QS500040507 Grant - others:GA ČR(CZ) GP524/05/P135 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : nitric oxide * macrophage s RAW 264.7 * nitric oxide sensor Subject RIV: BO - Biophysics Impact factor: 3.480, year: 2009

  18. Nitric oxide coordinates metabolism, growth, and development via the nuclear receptor E75

    OpenAIRE

    Cáceres, Lucía; Necakov, Aleksandar S.; Schwartz, Carol; Kimber, Sandra; Roberts, Ian J.H.; Krause, Henry M.

    2011-01-01

    Nitric oxide gas acts as a short-range signaling molecule in a vast array of important physiological processes, many of which include major changes in gene expression. How these genomic responses are induced, however, is poorly understood. Here, using genetic and chemical manipulations, we show that nitric oxide is produced in the Drosophila prothoracic gland, where it acts via the nuclear receptor ecdysone-induced protein 75 (E75), reversing its ability to interfere with its heterodimer part...

  19. Neuronal nitric oxide synthase is involved in the induction of NGF induced neck muscle nociception

    OpenAIRE

    Isaak, Andreas

    2011-01-01

    BACKGROUND: Neck muscle nociception mediated by nitric oxide may play a role in the pathophysiology of tension-type headache.OBJECTIVE: The present study addresses the involvement of neuronal nitric oxide synthase (nNOS) in the facilitation of neck muscle nociception after local application of nerve growth factor (NGF).METHODS: After administration of NGF into semispinal neck muscles, the impact of neck muscle noxious input on brainstem processing was monitored by the jaw-opening reflex in an...

  20. Thermodynamics of uranium and nitric acid extraction from aqueous solution of TBP/diluent

    International Nuclear Information System (INIS)

    Souza Freitas, R.F. de.

    1982-06-01

    A thermodynamically consistent procedure for predicting distribution equilibria for uranyl nitrate and nitric acid between an aqueous solution and 30 vol % tributyl phosphate (TBP) in a hydrocarbon diluent is studied. Experimental work is developed in order to obtain equilibrium data for the system uranyl nitrate, nitric acid, water and 30 vol % TBP in n-dodecane, at 25 0 C and 40 0 C. The theoretical equilibrium data, obtained with the aid of a computer, are compared with the experimental results. (Author) [pt

  1. Endothelial nitric oxide synthase: a potential therapeutic target for cerebrovascular diseases.

    Science.gov (United States)

    Zhu, Jinqiang; Song, Wanshan; Li, Lin; Fan, Xiang

    2016-03-22

    Endothelial nitric oxide (NO) is a significant signaling molecule that regulates cerebral blood flow (CBF), playing a pivotal role in the prevention and treatment of cerebrovascular diseases. However, achieving the expected therapeutic efficacy is difficult using direct administration of NO donors. Therefore, endothelial nitric oxide synthase (eNOS) becomes a potential therapeutic target for cerebrovascular diseases. This review summarizes the current evidence supporting the importance of CBF to cerebrovascular function, and the roles of NO and eNOS in CBF regulation.

  2. Comparison Between the Acute Pulmonary Vascular Effects of Oxygen with Nitric Oxide and Sildenafil

    Directory of Open Access Journals (Sweden)

    Ronald W. Day

    2015-03-01

    Full Text Available Objective. Right heart catheterization is performed in patients with pulmonary arterial hypertension to determine the severity of disease and their pulmonary vascular reactivity. The acute pulmonary vascular effect of inhaled nitric oxide is frequently used to identify patients who will respond favorably to vasodilator therapy. This study sought to determine whether the acute pulmonary vascular effects of oxygen with nitric oxide and intravenous sildenafil are similar. Methods. A retrospective, descriptive study of 13 individuals with pulmonary hypertension who underwent heart catheterization and acute vasodilator testing was performed. The hemodynamic measurements during five phases (21% to 53% oxygen, 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21% to 51% oxygen, and 21% to 51% oxygen with 0.05 mg/kg to 0.29 mg/kg intravenous sildenafil of the procedures were compared.Results. Mean pulmonary arterial pressure and pulmonary vascular resistance acutely decreased with 100% oxygen with nitric oxide, and 21% to 51% oxygen with sildenafil. Mean pulmonary arterial pressure (mm Hg, mean ± standard error of the mean was 38 ± 4 during 21% to 53% oxygen, 32 ± 3 during 100% oxygen, 29 ± 2 during 100% oxygen with nitric oxide, 37 ± 3 during 21% to 51% oxygen, and 32 ± 2 during 21% to 51% oxygen with sildenafil. There was not a significant correlation between the percent change in pulmonary vascular resistance from baseline with oxygen and nitric oxide, and from baseline with sildenafil (r2 = 0.011, p = 0.738. Conclusions. Oxygen with nitric oxide and sildenafil decreased pulmonary vascular resistance. However, the pulmonary vascular effects of oxygen and nitric oxide cannot be used to predict the acute response to sildenafil. Additional studies are needed to determine whether the acute response to sildenafil can be used to predict the long-term response to treatment with an oral phosphodiesterase V inhibitor.

  3. Inhibition of Nitric Oxide Synthesis and Gene Knockout of Neuronal Nitric Oxide Synthase Impaired Adaptation of Mouse Optokinetic Response Eye Movements

    OpenAIRE

    Katoh, Akira; Kitazawa, Hiromasa; Itohara, Shigeyoshi; Nagao, Soichi

    2000-01-01

    Nitric oxide (NO) plays a key role in synaptic transmission efficiency in the central nervous system. To gain an insight on the role of NO in cerebellar functions, we, here, measured the dynamics of the horizontal optokinetic response (HOKR) and vestibulo-ocular reflex (HVOR), and the adaptation of HOKR in mice locally injected with NG-monomethyl-l-arginine (L-NMMA) that inhibits NO synthesis and in mice devoid of neuronal nitric oxide synthase (nNOS). Local application of L-NMMA into the cer...

  4. Are exhaled nitric oxide measurements using the portable NIOX MINO repeatable?

    Directory of Open Access Journals (Sweden)

    Raza Abid

    2010-04-01

    Full Text Available Abstract Background Exhaled nitric oxide is a non-invasive marker of airway inflammation and a portable analyser, the NIOX MINO (Aerocrine AB, Solna, Sweden, is now available. This study aimed to assess the reproducibility of the NIOX MINO measurements across age, sex and lung function for both absolute and categorical exhaled nitric oxide values in two distinct groups of children and teenagers. Methods Paired exhaled nitric oxide readings were obtained from 494 teenagers, aged 16-18 years, enrolled in an unselected birth cohort and 65 young people, aged 6-17 years, with asthma enrolled in an interventional asthma management study. Results The birth cohort participants showed a high degree of variability between first and second exhaled nitric oxide readings (mean intra-participant difference 1.37 ppb, 95% limits of agreement -7.61 to 10.34 ppb, although there was very close agreement when values were categorised as low, normal, intermediate or high (kappa = 0.907, p Conclusions The reproducibility of exhaled nitric oxide is poor for absolute values but acceptable when values are categorised as low, normal, intermediate or high in children and teenagers. One measurement is therefore sufficient when using categorical exhaled nitric oxide values to direct asthma management but a mean of at least two measurements is required for absolute values.

  5. Differential modulation of nitric oxide synthases in aging: therapeutic opportunities

    Directory of Open Access Journals (Sweden)

    Stêfany Bruno De Assis Cau

    2012-06-01

    Full Text Available Vascular aging is the term that describes the structural and functional disturbances of the vasculature with advancing aging. The molecular mechanisms of aging-associated endothelial dysfunction are complex, but reduced nitric oxide (NO bioavailability and altered vascular expression and activity of NO synthase (NOS enzymes have been implicated as major players. Impaired vascular relaxation in aging has been attributed to reduced endothelial NOS (eNOS-derived NO, while increased inducible NOS (iNOS expression seems to account for nitrosative stress and disrupted vascular homeostasis. Although eNOS is considered the main source of NO in the vascular endothelium, neuronal NOS (nNOS also contributes to endothelial cells-derived NO, a mechanism that is reduced in aging. Pharmacological modulation of NO generation and expression/activity of NOS isoforms may represent a therapeutic alternative to prevent the progression of cardiovascular diseases. Accordingly, this review will focus on drugs that modulate NO bioavailability, such as nitrite anions and NO-releasing non-steroidal anti-inflammatory drugs, hormones (dehydroepiandrosterone and estrogen, statins, resveratrol and folic acid, since they may be useful to treat/to prevent aging-associated vascular dysfunction. The impact of these therapies on life quality in elderly and longevity will be discussed.

  6. Exhaled nitric oxide - circadian variations in healthy subjects

    Directory of Open Access Journals (Sweden)

    Antosova M

    2009-12-01

    Full Text Available Abstract Objective Exhaled nitric oxide (eNO has been suggested as a marker of airway inflammatory diseases. The level of eNO is influenced by many various factor including age, sex, menstrual cycle, exercise, food, drugs, etc. The aim of our study was to investigate a potential influence of circadian variation on eNO level in healthy subjects. Methods Measurements were performed in 44 women and 10 men, non-smokers, without respiratory tract infection in last 2 weeks. The eNO was detected at 4-hour intervals from 6 a.m. to 10 p.m. using an NIOX analyzer. We followed the ATS/ERS guidelines for eNO measurement and analysis. Results Peak of eNO levels were observed at 10 a.m. (11.1 ± 7.2 ppb, the lowest value was detected at 10 p.m. (10.0 ± 5.8 ppb. The difference was statistically significant (paired t-test, P Conclusions The daily variations in eNO, with the peak in the morning hours, could be of importance in clinical practice regarding the choice of optimal time for monitoring eNO in patients with respiratory disease.

  7. Effects of nitric oxide and nitrogen dioxide on bacterial growth

    Science.gov (United States)

    Mancinelli, R. L.; Mckay, C. P.

    1983-01-01

    While it is generally thought that the bactericidal effects of NO and NO2 derive from their reaction with water to form nitrous and nitric acids (Shank et al., 1962), this appears to be true only at high concentrations. The data presented here suggest that at low NO and NO2 concentrations, acids are not present in high enough concentrations to act as toxic agents. Reference is made to a study by Grant et al. (1979), which found that exposing acid forest soil to 1 ppm of NO2 did not cause the soil pH to drop. The results presented here show that at low concentrations of NO and NO2, the NO is bacteriostatic for some organisms and not for others, whereas NO2 may protect some bacteria from the inhibitory effects of NO. Since it has been shown that bacteria can divide while airborne (Dimmick et al., 1979), the present results suggest that NO at the low concentrations found in the atmosphere can select for resistant bacteria in the air and affect the viable airborne bacterial population.

  8. Efficacy of nitric oxide-liberating cream on pityriasis versicolor.

    Science.gov (United States)

    Jowkar, Farideh; Jamshidzadeh, Akram; Pakniyat, Soroush; Namazi, Mohammad Reza

    2010-03-01

    Tinea versicolor is a superficial fungal infection of the skin caused by Malassezia yeasts. Tinea versicolor is a common disease and has a high rate of recurrence. This is a prospective, double-blind, randomized, placebo-controlled clinical trial in Faghihi Hospital Dermatology Department. Participants were older than 10 years with a clinical diagnosis of tinea versicolor and positive KOH preparation, and were divided in two groups: active and control (32 individuals in each). They were randomized to receive either nitric oxide (NO)-liberating cream as the active group and placebo as a control. Creams were applied twice daily on the affected sites for 10 days. Sixty-four patients were entered into the study (31 male and 33 female). No significant difference was found between the two groups in terms of severity, age and sex distribution. There was significant improvement with acidified nitrite cream in the active group after 10 days (p = 0.000). NO is an important cytotoxic effector in immune defense against fungi that are too large to phagocyte. This study shows the efficacy of an exogenous NO-releasing cream in treating tinea versicolor.

  9. Nitric oxide measurements in the Arctic winter stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Fahey, D.W. (National Oceanic and Atmospheric Administration (USA)); Kawa, S.R. (National Oceanic and Atmospheric Administration (USA) Univ. of Colorado, Boulder (USA)); Chan, K.R. (NASA Ames Research Center, Moffett Field, CA (USA))

    1990-03-01

    Measurements of nitric oxide (NO) from five flights of the NASA ER-2 aircraft during the Airborne Arctic Stratospheric Expedition (AASE) are presented. The NO values and vertical gradient near 60{degree}N latitude are similar to previous measurements near 50{degree}N in winter (Ridley et al., 1984; 1987). The NO latitudinal gradient is distinctly negative outside of the polar vortex, approaching zero at the boundary of the vortex, and remaining below the 20 pptv detection limit inside the vortex. The low NO values in the vortex occur at solar zenith angles as low as 82{degree} indicating that NO{sub 2} values in the vortex are also low. Steady state NO{sub 2} and NO{sub x} (NO+NO{sub 2}) are calculated from measured NO, O{sub 3}, and ClO, and modeled photodissociation rates. NO{sub x} outside the vortex shows a negative dependence on latitude and solar zenith angle. The average ratio of NO{sub x} to NO{sub y} (at the same relative latitudes from different flight days) shows a strong latitude gradient with values near 0.08 at 12{degree} equatorward of the vortex edge, decreasing to less than 0.02 at the vortex boundary. Low NO{sub x} and NO{sub x}/NO{sub y} inside and near the vortex boundary may be indications of heterogeneous removal of ClONO{sub 2} and N{sub 2}O{sub 5}.

  10. Molecular dynamics simulation of nitric oxide in myoglobin

    Science.gov (United States)

    Lee, Myung Won; Meuwly, Markus

    2012-01-01

    The infrared (IR) spectroscopy and ligand migration of photodissociated nitric oxide (NO) in and around the active sites in myoglobin (Mb) are investigated. A distributed multipolar model for open-shell systems is developed and used, which allows one to realistically describe the charge distribution around the diatomic probe molecule. The IR spectra were computed from the trajectories for two conformational substates at various temperatures. The lines are narrow (width of 3–7 cm–1 at 20–100 K), in agreement with the experimental observations where they have widths of 4–5 cm–1 at 4 K. It is found that within one conformational substate (B or C) the splitting of the spectrum can be correctly described compared with recent experiments. Similar to photodissociated CO in Mb, additional substates exist for NO in Mb, which are separated by barriers below 1 kcal/mol. Contrary to full quantum mechanical calculations, however, the force field and mixed QM/MM simulations do not correctly describe the relative shifts between the B- and C-states relative to gas-phase NO. Free energy simulations establish that NO preferably localizes in the distal site and the barrier for migration to the neighboring Xe4 pocket is ΔGB→C = 1.7–2.0 kcal/mol. The reverse barrier is ΔGB←C = 0.7 kcal/mol, which agrees well with the experimental value of 0.7 kcal/mol, estimated from kinetic data.

  11. Nitric oxide and superoxide: interference with hypoxic signaling.

    Science.gov (United States)

    Brüne, Bernhard; Zhou, Jie

    2007-07-15

    Sensing and responding to changes in oxygen partial pressure assures that the cellular oxygen supply is tightly controlled in order to balance the risks of oxidative damage vs. oxygen deficiency. The hypoxia inducible factor (HIF) regulatory system is controlled by prolyl hydroxylases (PHDs), the von Hippel Lindau protein (pVHL), and the 26S proteasome and transduces changes in oxygenation to adequate intracellular adaptive responses. A functional HIF response requires stabilization of the alpha-subunit, e.g. HIF-1alpha, during hypoxia and dimerization with HIF-1beta, to drive target gene activation. Intriguingly, high concentrations of nitric oxide (NO) stabilize HIF-1alpha and thus mimic a hypoxic response under normoxia. Mechanistically, NO blocks PHD activity and attenuates proline hydroxylation of HIF-1alpha. This causes dissociation of pVHL from HIF-1alpha and, consequently, HIF-1alpha accumulates because proteasomal destruction is impaired. However, during hypoxia low concentrations of NO facilitate destruction of HIF-1alpha and thus reverse HIF signaling. Under these conditions, NO impairs respiration and avoids oxygen gradients that limit PHD activity. An additional layer of complexity comprises the interaction of NO with O(2)(-). Signaling qualities attributed to NO are antagonized by compensatory flux rates of O(2)(-) and vice versa to adjust levels of HIF-1alpha under normoxia and hypoxia. The liaison of NO and hypoxia is versatile and ranges from courting to matrimony and divorce.

  12. Hypoxia tolerance, nitric oxide, and nitrite: lessons from extreme animals.

    Science.gov (United States)

    Fago, Angela; Jensen, Frank B

    2015-03-01

    Among vertebrates able to tolerate periods of oxygen deprivation, the painted and red-eared slider turtles (Chrysemys picta and Trachemys scripta) and the crucian carp (Carassius carassius) are the most extreme and can survive even months of total lack of oxygen during winter. The key to hypoxia survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and-in air-breathing animals-redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite nitrite. The aim of this review is to highlight recent work illustrating the widespread roles of NO and nitrite in the tolerance to extreme oxygen deprivation, in particular in the red-eared slider turtle and crucian carp, but also in diving marine mammals. The emerging picture underscores the importance of NO and nitrite signaling in the adaptive response to hypoxia in vertebrate animals. ©2015 Int. Union Physiol. Sci./Am. Physiol. Soc.

  13. Structural dynamics controls nitric oxide affinity in nitrophorin 4.

    Science.gov (United States)

    Nienhaus, Karin; Maes, Estelle M; Weichsel, Andrzej; Montfort, William R; Nienhaus, G Ulrich

    2004-09-17

    Nitrophorin 4 (NP4) is one of seven nitric oxide (NO) transporting proteins in the blood-sucking insect Rhodnius prolixus. In its physiological function, NO binds to a ferric iron centered in a highly ruffled heme plane. Carbon monoxide (CO) also binds after reduction of the heme iron. Here we have used Fourier transform infrared spectroscopy at cryogenic temperatures to study CO and NO binding and migration in NP4, complemented by x-ray cryo-crystallography on xenon-containing NP4 crystals to identify cavities that may serve as ligand docking sites. Multiple infrared stretching bands of the heme-bound ligands indicate different active site conformations with varying degrees of hydrophobicity. Narrow infrared stretching bands are observed for photodissociated CO and NO; temperature-derivative spectroscopy shows that these bands are associated with ligand docking sites close to the extremely reactive heme iron. No rebinding from distinct secondary sites was detected, although two xenon binding cavities were observed in the x-ray structure. Photolysis studies at approximately 200 K show efficient NO photoproduct formation in the more hydrophilic, open NP4 conformation. This result suggests that ligand escape is facilitated in this conformation, and blockage of the active site by water hinders immediate reassociation of NO to the ferric iron. In the closed, low-pH conformation, ligand escape from the active site of NP4 is prevented by an extremely reactive heme iron and the absence of secondary ligand docking sites.

  14. Nitric oxide synthetase and Helicobacter pylori in patients undergoing appendicectomy.

    LENUS (Irish Health Repository)

    Kell, M R

    2012-02-03

    BACKGROUND: This study was designed to determine whether Helicobacter pylori forms part of the normal microenvironment of the appendix, whether it plays a role in the pathogenesis of acute appendicitis, and whether it is associated with increased expression of inducible nitric oxide synthetase (iNOS) in appendicular macrophages. METHODS: Serology for H. pylori was performed on 51 consecutive patients undergoing emergency appendicectomy. Appendix samples were tested for urease activity, cultured and stained for H. pylori, graded according to the degree of inflammatory infiltrate, and probed immunohistochemically for iNOS expression. RESULTS: The mean age of the patients was 21 (range 7-51) years. Seventeen patients (33 per cent) were seropositive for H. pylori but no evidence of H. pylori was found in any appendix specimen. However, an enhanced inflammatory cell infiltration was observed in seropositive patients (P < 0.04) and the expression of macrophage iNOS in the mucosa of normal and inflamed appendix specimens was increased (P < 0.01). CONCLUSION: H. pylori does not colonize the appendix and is unlikely to be a pathogenic stimulus for appendicitis. Priming effects on mucosal immunology downstream from the foregut may occur after infection with H. pylori.

  15. Evaluation of Mapleson systems for administration of inhaled nitric oxide.

    Science.gov (United States)

    Kukita, I; Okamoto, K; Sato, T; Shibata, Y; Shiihara, K; Kikuta, K

    1996-03-01

    To assess the safety of nitric oxide (NO) inhalation during manual-controlled ventilation using Mapleson A, D, and F systems, we examined nitrogen dioxide (NO2) production using a chemiluminescence analyzer. The NO concentration was changed from 0 to 19 parts per million (ppm), and at each level of NO the oxygen (O2) concentration was changed from 21% to 100%. The NO2 concentration was observed to increase when either the O2 or NO concentration was increased. The maximum NO2 concentrations (mean ± standard deviation) of the Mapleson A, D, and F systems were 0.20±0.03, 0.15±0.03, and 0.17±0.02 ppm, respectively, when the concentrations of NO and O2 were 19 ppm and 100%, respectively. The NO2 concentrations of the Mapleson A system were significantly higher than those of either the Mapleson D or F system at 4, 8, and 12 ppm NO and 100% O2, and than that of the Mapleson D system at 19 ppm NO and 100% O2. From the viewpoint of NO2 production, we suggest that the Mapleson D and F systems are safer than the Mapleson A system when manual-controlled ventilation is required.

  16. Postprandial lipids accelerate and redirect nitric oxide consumption in plasma.

    Science.gov (United States)

    Vrancken, Kurt; Schroeder, Hobe J; Longo, Lawrence D; Power, Gordon G; Blood, Arlin B

    2016-05-01

    Nitric oxide (NO) and O2 are both three-to four-fold more soluble in biological lipids than in aqueous solutions. Their higher concentration within plasma lipids accelerates NO autoxidation to an extent that may be of importance to overall NO bioactivity. This study was undertaken to test the hypothesis that increased plasma lipids after a high-fat meal appreciably accelerate NO metabolism and alter the byproducts formed. We found that plasma collected from subjects after consumption of a single high-fat meal had a higher capacity for NO consumption and consumed NO more rapidly compared to fasting plasma. This increased NO consumption showed a direct correlation with plasma triglyceride concentrations (p = 0.006). The accelerated NO consumption in postprandial plasma was reversed by removal of the lipids from the plasma, was mimicked by the addition of hydrophobic micelles to aqueous buffer, and could not be explained by the presence of either free hemoglobin or ceruloplasmin. The products of NO consumption were shifted in postprandial plasma, with 55% more nitrite (n = 12, p = 0.002) but 50% less SNO (n = 12, p = 0.03) production compared to matched fasted plasma. Modeling calculations indicated that NO autoxidation was accelerated by about 48-fold in the presence of plasma lipids. We conclude that postprandial triglyceride-rich lipoproteins exert a significant influence on NO metabolism in plasma. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Carvedilol stimulates nitric oxide synthesis in rat cardiac myocytes.

    Science.gov (United States)

    Kurosaki, K; Ikeda, U; Maeda, Y; Shimada, K

    2000-02-01

    The purpose of this study was to investigate the effects of the beta-adrenergic blocker carvedilol on nitric oxide (NO) synthesis in cardiac myocytes. We measured the accumulation of nitrite, a stable oxidation product of NO, and the expression of inducible NO synthase (iNOS) protein in cultured neonatal rat cardiac myocytes. Incubation of the cultures with interleukin 1 beta (IL-1 beta; 10 ng/ml) caused a marked increase in nitrite production. Although carvedilol alone showed no effect on nitrite accumulation, it significantly enhanced IL-1 beta-induced nitrite production by cardiac myocytes. The effect of carvedilol was completely abolished in the presence of aminoguanidine or actinomycin D. The nitrite production enhanced by carvedilol was accompanied by increased iNOS protein expression. Unlike carvedilol, other beta-blockers, namely propranolol, atenolol and arotinolol, did not enhance IL-1 beta-induced nitrite production. Addition of isoproterenol significantly increased nitrite production by IL-1 beta-stimulated cardiac myocytes. Atenolol suppressed this isoproterenol-induced nitrite accumulation, while carvedilol further increased the nitrite accumulation. These findings indicate that carvedilol increases NO synthesis in IL-1 beta-stimulated rat cardiac myocytes by a beta-adrenoceptor-independent mechanism. Copyright 2000 Academic Press.

  18. Nitric oxide removal by wastewater bacteria in a biotrickling filter.

    Science.gov (United States)

    Niu, Hejingying; Leung, Dennis Y C; Wong, Chifat; Zhang, Tong; Chan, Mayngor; Leung, Fred C C

    2014-03-01

    Nitric oxide (NO) is one of the most important air pollutants in atmosphere mainly emitted from combustion source. A biotrickling filter was designed and operated to remove NO from an air stream using bacteria extracted from the sewage sludge of a municipal sewage treatment plant. To obtain the best operation conditions for the biotrickling filter, orthogonal experiments (L9(3(4))) were designed. Inlet oxygen concentration was found to be the most significant factor of the biotrickling filter and has a significant negative effect on the system. The optimal conditions of the biotrickling filter occurred at a temperature of 40°C, a pH of 8.0 and a chemical oxygen demand of 165 mg/L in the recycled water with no oxygen in the system. The bacteria sample was detected by DNA sequencing technology and showed 93%-98% similarity to Pseudomonas mendocina. Moreover, a full gene sequencing results indicated the bacterium was a brand new strain and named as P. mendocina DLHK. This strain can transfer nitrate to organic nitrogen. The result suggested the assimilation nitrogen process in this system. Through the isotope experimental analysis, two intermediate products ((15)NO and (15)N2O) were found. The results indicated the denitrification function and capability of the biotrickling filter in removing NO. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  19. Uncoupling of Vascular Nitric Oxide Synthase Caused by Intermittent Hypoxia

    Directory of Open Access Journals (Sweden)

    Mohammad Badran

    2016-01-01

    Full Text Available Objective. Obstructive sleep apnea (OSA, characterized by chronic intermittent hypoxia (CIH, is often present in diabetic (DB patients. Both conditions are associated with endothelial dysfunction and cardiovascular disease. We hypothesized that diabetic endothelial dysfunction is further compromised by CIH. Methods. Adult male diabetic (BKS.Cg-Dock7m +/+ Leprdb/J (db/db mice (10 weeks old and their heterozygote littermates were subjected to CIH or intermittent air (IA for 8 weeks. Mice were separated into 4 groups: IA (intermittent air nondiabetic, IH (intermittent hypoxia nondiabetic, IADB (intermittent air diabetic, and IHDB (intermittent hypoxia diabetic groups. Endothelium-dependent and endothelium-independent relaxation and modulation by basal nitric oxide (NO were analyzed using wire myograph. Plasma 8-isoprostane, interleukin-6 (IL-6, and asymmetric dimethylarginine (ADMA were measured using ELISA. Uncoupling of eNOS was measured using dihydroethidium (DHE staining. Results. Endothelium-dependent vasodilation and basal NO production were significantly impaired in the IH and IADB group compared to IA group but was more pronounced in IHDB group. Levels of 8-isoprostane, IL-6, ADMA, and eNOS uncoupling were ≈2-fold higher in IH and IADB groups and were further increased in the IHDB group. Conclusion. Endothelial dysfunction is more pronounced in diabetic mice subjected to CIH compared to diabetic or CIH mice alone. Oxidative stress, ADMA, and eNOS uncoupling were exacerbated by CIH in diabetic mice.

  20. Nitric oxide and nitrosative stress tolerance in yeast

    Science.gov (United States)

    Tillmann, Anna; Gow, Neil A.R.; Brown, Alistair J.P.

    2013-01-01

    The opportunistic human fungal pathogen Candida albicans encounters diverse environmental stresses when it is in contact with its host. When colonising and invading human tissues C. albicans is exposed to reactive oxygen (ROS) and reactive nitrogen intermediates (RNI). ROS and RNI are generated in the first line of host defence by phagocytic cells such as macrophages and neutrophils. In order to escape these host-induced oxidative and nitrosative stresses C. albicans has developed various detoxification mechanisms. One such mechanism is the detoxification of nitric oxide (NO) to nitrate by the flavohaemoglobin enzyme, CaYhb1. Members of the haemoglobin superfamily are highly conserved and are found in archaea, eukaryotes, and bacteria. Flavohemoglobins have a dioxygenase activity (NOD) and contain three domains: a globin domain, an FAD-binding domain, and an NAD(P)-binding domain. Here we examine the nitrosative stress response in three fungal models: the pathogenic yeast C. albicans, the benign budding yeast Saccharomyces cerevisiae, and the benign fission yeast Schizosaccharomyces pombe. We compare their enzymatic and non-enzymatic NO and RNI detoxification mechanisms and summarise fungal responses to nitrosative stress. PMID:21265777

  1. REGULATION OF OBESITY AND INSULIN RESISTANCE BY NITRIC OXIDE

    Science.gov (United States)

    Sansbury, Brian E.; Hill, Bradford G.

    2014-01-01

    Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a world-wide pandemic with few tangible and safe treatment options. While it is generally accepted that the primary cause of obesity is energy imbalance, i.e., the calories consumed are greater than are utilized, understanding how caloric balance is regulated has proven a challenge. Many “distal” causes of obesity, such as the structural environment, occupation, and social influences, are exceedingly difficult to change or manipulate. Hence, molecular processes and pathways more proximal to the origins of obesity—those that directly regulate energy metabolism or caloric intake—appear to be more feasible targets for therapy. In particular, nitric oxide (NO) is emerging as a central regulator of energy metabolism and body composition. NO bioavailability is decreased in animal models of diet-induced obesity and in obese and insulin resistant patients, and increasing NO output has remarkable effects on obesity and insulin resistance. This review discusses the role of NO in regulating adiposity and insulin sensitivity and places its modes of action into context with the known causes and consequences of metabolic disease. PMID:24878261

  2. Role of nitric oxide and superoxide in Giardia lamblia killing

    Directory of Open Access Journals (Sweden)

    P.D. Fernandes

    1997-01-01

    Full Text Available Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine. Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites. This effect was inhibited (>90% by an NO synthase inhibitor (200 µM and unaffected by superoxide dismutase (SOD, 300 U/ml. Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP and sodium nitroprusside (SNP in a dose-dependent manner (LD50 300 and 50 µM, respectively. A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1, did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM. The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM. These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

  3. New nitric oxide donors based on ruthenium complexes

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    C.N. Lunardi

    2009-01-01

    Full Text Available Nitric oxide (NO donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2- by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension.

  4. Nitric Oxide and Peroxynitrite in Health and Disease

    Science.gov (United States)

    PACHER, PÁL; BECKMAN, JOSEPH S.; LIAUDET, LUCAS

    2008-01-01

    The discovery that mammalian cells have the ability to synthesize the free radical nitric oxide (NO) has stimulated an extraordinary impetus for scientific research in all the fields of biology and medicine. Since its early description as an endothelial-derived relaxing factor, NO has emerged as a fundamental signaling device regulating virtually every critical cellular function, as well as a potent mediator of cellular damage in a wide range of conditions. Recent evidence indicates that most of the cytotoxicity attributed to NO is rather due to peroxynitrite, produced from the diffusion-controlled reaction between NO and another free radical, the superoxide anion. Peroxynitrite interacts with lipids, DNA, and proteins via direct oxidative reactions or via indirect, radical-mediated mechanisms. These reactions trigger cellular responses ranging from subtle modulations of cell signaling to overwhelming oxidative injury, committing cells to necrosis or apoptosis. In vivo, peroxynitrite generation represents a crucial pathogenic mechanism in conditions such as stroke, myocardial infarction, chronic heart failure, diabetes, circulatory shock, chronic inflammatory diseases, cancer, and neurodegenerative disorders. Hence, novel pharmacological strategies aimed at removing peroxynitrite might represent powerful therapeutic tools in the future. Evidence supporting these novel roles of NO and peroxynitrite is presented in detail in this review. PMID:17237348

  5. Potential use and perspectives of nitric oxide donors in agriculture.

    Science.gov (United States)

    Marvasi, Massimiliano

    2017-03-01

    Nitric oxide (NO) has emerged in the last 30 years as a key molecule involved in many physiological processes in plants, animals and bacteria. Current research has shown that NO can be delivered via donor molecules. In such cases, the NO release rate is dependent on the chemical structure of the donor itself and on the chemical environment. Despite NO's powerful signaling effect in plants and animals, the application of NO donors in agriculture is currently not implemented and research remains mainly at the experimental level. Technological development in the field of NO donors is rapidly expanding in scope to include controlling seed germination, plant development, ripening and increasing shelf-life of produce. Potential applications in animal production have also been identified. This concise review focuses on the use of donors that have shown potential biotechnological applications in agriculture. Insights are provided into (i) the role of donors in plant production, (ii) the potential use of donors in animal production and (iii) future approaches to explore the use and applications of donors for the benefit of agriculture. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Nitric oxide cycle in mammals and the cyclicity principle.

    Science.gov (United States)

    Reutov, V P

    2002-03-01

    This paper continues a series of reports considering nitric oxide (NO) and its cyclic conversions in mammals. Numerous facts are summarized with the goal of developing a general concept that would allow the statement of the multiple effects of NO on various systems of living organisms in the form of a short and comprehensive law. The current state of biological aspects of NO research is analyzed in term of elucidation of possible role of these studies in the system of biological sciences. The general concept is based on a notion on cyclic conversions of NO and its metabolites. NO cycles in living organisms and nitrogen turnover in the biosphere and also the Bethe nitrogen-carbon cycle in star matter are considered. A hypothesis that the cyclic organization of processes in living organisms and the biosphere reflects the evolution of life is proposed: the development of physiological functions and metabolism are suggested to be closely related to space and evolution of the Earth as a planet of the Solar System.

  7. Longevity of Epidendrum ibaguense Kunth inflorescences treated with nitric oxide

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    Luciana Marques Vieira

    2016-11-01

    Full Text Available Nitric oxide (NO acts as anti senescence substance, which may extend the postharvest life of fruits, vegetables and flowers when they are treated with micro molar concentrations of compounds like the donor sodium nitroprusside (SNP. This work aimed to evaluate the effect pulsing or spraying of NO on the longevity of cut Epidendrum ibaguense inflorescences. After harvested, the inflorescences were pulsed for 6, 24 or 48 hours with 5, 10, 50, 100 and 500 µM SNP or sprayed until run off with the same mentioned solutions. Controls were treated with distilled water. After the treatment, the flowers were placed in deionized water, which was changed every 2 days. No significant differences were observed on the longevity of flowers treated with 5, 10, 50 or 100 µM SNP, regardless of the mode of application. Inflorescences treated with 500 µM SNP had reduced longevity and increased flower abscission. In inflorescences kept in SNP solution, toxic symptoms such as darkening of the labellum resulting in reduced longevity compared with the control. The longevity of inflorescences sprayed with 500 µM SNP reduced from 6.8±0.57 to 5.1±0.82 days. Collectively, NO treatments were not able to extend the shelf life of E. ibaguense inflorescences and high concentrations of the NO donor compound in vase solution or spraying leads to toxicity symptoms on the flower labellum.

  8. Insulin-stimulated phosphorylation of endothelial nitric oxide synthase at serine-615 contributes to nitric oxide synthesis.

    Science.gov (United States)

    Ritchie, Stuart A; Kohlhaas, Christine F; Boyd, Alasdair R; Yalla, Krishna C; Walsh, Kenneth; Connell, John M C; Salt, Ian P

    2010-01-27

    Insulin stimulates endothelial NO (nitric oxide) synthesis via PKB (protein kinase B)/Akt-mediated phosphorylation and activation of eNOS (endothelial NO synthase) at Ser-1177. In previous studies, we have demonstrated that stimulation of eNOS phosphorylation at Ser-1177 may be required, yet is not sufficient for insulin-stimulated NO synthesis. We therefore investigated the role of phosphorylation of eNOS at alternative sites to Ser-1177 as candidate parallel mechanisms contributing to insulin-stimulated NO synthesis. Stimulation of human aortic endothelial cells with insulin rapidly stimulated phosphorylation of both Ser-615 and Ser-1177 on eNOS, whereas phosphorylation of Ser-114, Thr-495 and Ser-633 was unaffected. Insulin-stimulated Ser-615 phosphorylation was abrogated by incubation with the PI3K (phosphoinositide 3-kinase) inhibitor wortmannin, infection with adenoviruses expressing a dominant-negative mutant PKB/Akt or pre-incubation with TNFalpha (tumour necrosis factor alpha), but was unaffected by high culture glucose concentrations. Mutation of Ser-615 to alanine reduced insulin-stimulated NO synthesis, whereas mutation of Ser-615 to aspartic acid increased NO production by NOS in which Ser-1177 had been mutated to an aspartic acid residue. We propose that the rapid PKB-mediated stimulation of phosphorylation of Ser-615 contributes to insulin-stimulated NO synthesis.

  9. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Bhupesh, E-mail: drbhupeshresearch@gmail.com; Sharma, P.M.

    2013-11-15

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential

  10. Posttranscriptional and transcriptional regulation of endothelial nitric-oxide synthase during hypoxia: the role of microRNAs.

    Science.gov (United States)

    Kalinowski, Leszek; Janaszak-Jasiecka, Anna; Siekierzycka, Anna; Bartoszewska, Sylwia; Woźniak, Marcin; Lejnowski, Dawid; Collawn, James F; Bartoszewski, Rafal

    2016-01-01

    Understanding the cellular pathways that regulate endothelial nitric oxide (eNOS, NOS3 ) expression and consequently nitric oxide (NO) bioavailability during hypoxia is a necessary aspect in the development of novel treatments for cardiovascular disorders. eNOS expression and eNOS-dependent NO cellular signaling during hypoxia promote an equilibrium of transcriptional and posttranscriptional molecular mechanisms that belong to both proapoptotic and survival pathways. Furthermore, NO bioavailability results not only from eNOS levels, but also relies on the presence of eNOS substrate and cofactors, the phosphorylation status of eNOS, and the presence of reactive oxygen species (ROS) that can inactivate eNOS. Since both NOS3 levels and these signaling pathways can also be a subject of posttranscriptional modulation by microRNAs (miRNAs), this class of short noncoding RNAs contribute another level of regulation for NO bioavailability. As miRNA antagomirs or specific target protectors could be used in therapeutic approaches to regulate NO levels, either by changing NOS3 mRNA stability or through factors governing eNOS activity, it is critical to understand their role in governing eNOS activity during hypoxa. In contrast to a large number of miRNAs reported to the change eNOS expression during hypoxia, only a few miRNAs modulate eNOS activity. Furthermore, impaired miRNA biogenesis leads to NOS3 mRNA stabilization under hypoxia. Here we discuss the recent studies that define miRNAs' role in maintaining endothelial NO bioavailability emphasizing those miRNAs that directly modulate NOS3 expression or eNOS activity.

  11. Caveolin-1-mediated post-transcriptional regulation of inducible nitric oxide synthase in human colon carcinoma cells

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    EMANUELA FELLEY-BOSCO

    2002-01-01

    Full Text Available Reactive oxygen species are now widely recognized as important players contributing both to cell homeostasis and the development of disease. In this respect nitric oxide (NO is no exception. The discussion here will center on regulation of the inducible form of nitric oxide synthase (iNOS for two reasons. First, only iNOS produces micromolar NO concentrations, amounts that are high by comparison with the picomolar to nanomolar concentrations resulting from Ca2+-controlled NO production by endothelial eNOS or neuronal nNOS. Second, iNOS is not constitutively expressed in cells and regulation of this isoenzyme, in contrast to endothelial eNOS or neuronal nNOS, is widely considered to occur at the transcriptional level only. In particular, we were interested in the possibility that caveolin-1, a protein that functions as a tumor suppressor in colon carcinoma cells (Bender et al., 2002; this issue, might regulate iNOS activity. Our results provide evidence for the existence of a post-transcriptional mechanism controlling iNOS protein levels that involves caveolin-1-dependent sequestration of iNOS within a detergent-insoluble compartment. Interestingly, despite the high degree of conservation of the caveolin-1 scaffolding domain binding motif within all NOS enzymes, the interaction detected between caveolin-1 and iNOS in vitro is crucially dependent on presence of a caveolin-1 sequence element immediately adjacent to the scaffolding domain. A model is presented summarizing the salient aspects of these results. These observations are important in the context of tumor biology, since down-regulation of caveolin-1 is predicted to promote uncontrolled iNOS activity, genotoxic damage and thereby facilitate tumor development in humans

  12. The mechanism of the nitric oxide-mediated enhancement of tert-butylhydroperoxide-induced DNA single strand breakage

    Science.gov (United States)

    Guidarelli, Andrea; Clementi, Emilio; Sciorati, Clara; Cantoni, Orazio

    1998-01-01

    Caffeine (Cf) enhances the DNA cleavage induced by tert-butylhydroperoxide (tB-OOH) in U937 cells via a mechanism involving Ca2+-dependent mitochondrial formation of DNA-damaging species (Guidarelli et al., 1997b). Nitric oxide (NO) is not involved in this process since U937 cells do not express the constitutive nitric oxide synthase (cNOS).Treatment with the NO donors S-nitroso-N-acetyl-penicillamine (SNAP, 10 μM), or S-nitrosoglutathione (GSNO, 300 μM), however, potentiated the DNA strand scission induced by 200 μM tB-OOH. The DNA lesions generated by tB-OOH alone, or combined with SNAP, were repaired with superimposable kinetics and were insensitive to anti-oxidants and peroxynitrite scavengers but suppressed by iron chelators.SNAP or GSNO did not cause mitochondrial Ca2+ accumulation but their enhancing effects on the tB-OOH-induced DNA strand scission were prevented by ruthenium red, an inhibitor of the calcium uniporter of mitochondria. Furthermore, the enhancing effects of both SNAP and GSNO were identical to and not additive with those promoted by the Ca2+-mobilizing agents Cf or ATP.The SNAP- or GSNO-mediated enhancement of the tB-OOH-induced DNA cleavage was abolished by the respiratory chain inhibitors rotenone and myxothiazol and was not apparent in respiration-deficient cells.It is concluded that, in cells which do not express the enzyme cNOS, exogenous NO enhances the accumulation of DNA single strand breaks induced by tB-OOH via a mechanism involving inhibition of complex III. PMID:9846647

  13. Scuba diving induces nitric oxide synthesis and the expression of inflammatory and regulatory genes of the immune response in neutrophils.

    Science.gov (United States)

    Sureda, Antoni; Batle, Juan M; Capó, Xavier; Martorell, Miquel; Córdova, Alfredo; Tur, Josep A; Pons, Antoni

    2014-09-01

    Scuba diving, characterized by hyperoxia and hyperbaria, could increase reactive oxygen species production which acts as signaling molecules to induce adaptation against oxidative stress. The aim was to study the effects of scuba diving immersion on neutrophil inflammatory response, the induction of oxidative damage, and the NO synthesis. Nine male divers performed a dive at 50 m depth for a total time of 35 min. Blood samples were obtained at rest before the dive, after the dive, and 3 h after the diving session. Markers of oxidative and nitrosative damage, nitrite, and the gene expression of genes related with the synthesis of nitric oxide and lipid mediators, cytokine synthesis, and inflammation were determined in neutrophils. The mRNA levels of genes related with the inflammatory and immune response of neutrophils, except TNF-α, myeloperoxidase, and toll-like receptor (TLR) 2, significantly increased after the recovery period respect to predive and postdive levels. NF-κB, IL-6, and TLR4 gene expression reported significant differences immediately after diving respect to the predive values. Protein nitrotyrosine levels significantly rose after diving and remained high during recovery, whereas no significant differences were reported in malondialdehyde. Neutrophil nitrite levels as indicative of inducible nitric oxide synthase (iNOS) activity progressively increased after diving and recovery. The iNOS protein levels maintained the basal values in all situations. Scuba diving which combines hyperoxia, hyperbaria, and acute exercise induces nitrosative damage with increased nitrotyrosine levels and an inflammatory response in neutrophils. Copyright © 2014 the American Physiological Society.

  14. Investigation on the Protective Role of Nitric Oxide in Reducing Damages Induced by Salinity Stress in Calendula officinalis L.

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    maryam jabbarzadeh

    2017-02-01

    Full Text Available Introduction: Salinity is one of the most important environmental factors that regulates plant growth and development, and limits plant production. Researchers have shown that some plant growth regulators such as nitric oxide improve the plants resistance to environmental stresses such as heat, cold, drought and salinity. Sodium nitroprusside (SNP commonly has been used as nitric oxide (NO donor in plants. NO is a diffusible gaseous free radical. Low concentrations of NO inhibit the production of reactive oxygen species and protect plants against ROS damages. The aim of this study was to evaluate the role of SNP as NO donor on salt tolerance of Calendula officinalis and its effects on some morphological, physiological and biochemical characteristics of this plant. Materials and Methods: In this study, the effects of salinity (0, 25, 50, 75 and 100 mM and sodium nitroprusside (0.0, 0.25, 0.50 and 0.75 mM on morphological and physiological characteristics of Calendula officinalis L. were investigated. Total leaf area and number of leaves were determined in the end of the experiment. Electrolyte leakage was used to asses’ membrane permeability. This procedure was based on Lutts et al.,1995. Soluble sugars were extracted and estimated by the method of Irigoyen et al., 1992. Chlorophyll a, b and carotenoid content were calculated from the absorbance of extract at 653, 666 and 470 nm using the formula of Dere et al., 1998. Proline was extracted by the method of Bates et al., 1973. DPPH radical- scavenging activity of sample was performed as described previously of Cleep et al., 2012. The SAS software was used for the analysis of variance (ANOVA, comparisons with P

  15. Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation

    Science.gov (United States)

    Nguyen, Minh Cong; Park, Jong Taek; Jeon, Yeong Gwan; Jeon, Byeong Hwa; Hoe, Kwang Lae; Kim, Young Myeong

    2016-01-01

    Purpose Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. Materials and Methods Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. Results SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. NG-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. Conclusion These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions. PMID:27593859

  16. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    International Nuclear Information System (INIS)

    Sharma, Bhupesh; Sharma, P.M.

    2013-01-01

    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential in

  17. The application of nitric oxide to control biofouling of membrane bioreactors.

    Science.gov (United States)

    Luo, Jinxue; Zhang, Jinsong; Barnes, Robert J; Tan, Xiaohui; McDougald, Diane; Fane, Anthony G; Zhuang, Guoqiang; Kjelleberg, Staffan; Cohen, Yehuda; Rice, Scott A

    2015-05-01

    A novel strategy to control membrane bioreactor (MBR) biofouling using the nitric oxide (NO) donor compound PROLI NONOate was examined. When the biofilm was pre-established on membranes at transmembrane pressure (TMP) of 88-90 kPa, backwashing of the membrane module with 80 μM PROLI NONOate for 45 min once daily for 37 days reduced the fouling resistance (Rf ) by 56%. Similarly, a daily, 1 h exposure of the membrane to 80 μM PROLI NONOate from the commencement of MBR operation for 85 days resulted in reduction of the TMP and Rf by 32.3% and 28.2%. The microbial community in the control MBR was observed to change from days 71 to 85, which correlates with the rapid TMP increase. Interestingly, NO-treated biofilms at 85 days had a higher similarity with the control biofilms at 71 days relative to the control biofilms at 85 days, indicating that the NO treatment delayed the development of biofilm bacterial community. Despite this difference, sequence analysis indicated that NO treatment did not result in a significant shift in the dominant fouling species. Confocal microscopy revealed that the biomass of biopolymers and microorganisms in biofilms were all reduced on the PROLI NONOate-treated membranes, where there were reductions of 37.7% for proteins and 66.7% for microbial cells, which correlates with the reduction in TMP. These results suggest that NO treatment could be a promising strategy to control biofouling in MBRs. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  18. BACTERIAL CLEARANCE IN SEPTIC MICE IS MODULATED BY MCP-1/CCL2 AND NITRIC OXIDE

    Science.gov (United States)

    Gomes, Rachel N.; Teixeira-Cunha, Mariana G. A.; Figueiredo, Rodrigo T.; Almeida, Patricia E.; Alves, Silvio C.; Bozza, Patrícia T.; Bozza, Fernando A.; Bozza, Marcelo T.; Zimmerman, Guy A.; Castro-Faria-Neto, Hugo C.

    2013-01-01

    Bacterial clearance is one of the most important beneficial consequences of the innate immune response. Chemokines are important mediators controlling leukocyte trafficking and activation, whereas reactive oxygen and nitrogen species are effectors in bacterial killing. In the present work, we used in vivo and in vitro models of infections to study the role of monocyte chemoattractant protein 1 (MCP-1)/CCL2 and nitric oxide (NO) in the bacterial clearance in sepsis. Our results show that MCP-1/CCL2 and NO levels are increased in the peritoneal cavity of mice 6 h after sepsis induced by cecal ligation and puncture. Pretreatment with anti–MCP-1/CCL2 monoclonal antibodies increased the number of colony-forming units (CFUs) recovered in the peritoneal lavage fluid. Moreover, CFU counts were increased in the peritoneal fluid of CCR2−/− mice subjected to cecal ligation and puncture. In vitro stimulation of peritoneal macrophages with recombinant MCP-1/CCL2 reduced CFU counts in the supernatant after challenge with Escherichia coli. Conversely, treatment with anti–MCP-1/CCL2 increased CFU counts under the same experimental condition. Stimulation of cultured macrophages with MCP-1/CCL2 and interferon had a synergistic effect on NO production. Macrophages from CCL2−/− mice showed a consistent decrease in NO production when compared with wild-type controls after stimulation with LPS + interferon. Finally, we showed incubation of macrophages with E. coli, and the ERK inhibitor U0126 increased CFU numbers and decreased intracellular levels of NO. In conclusion, we demonstrated for the first time that MCP-1/CCL2 has a crucial role in the clearance of bacteria by mechanisms involving increased expression of inducible NO synthase and production of NO by ERK signaling pathways. PMID:23247123

  19. Introducing a 2-His-1-Glu Nonheme Iron Center into Myoglobin Confers Nitric Oxide Reductase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Y Lin; N Yeung; Y Gao; K Miner; L Lei; H Robinson; Y Lu

    2011-12-31

    A conserved 2-His-1-Glu metal center, as found in natural nonheme iron-containing enzymes, was engineered into sperm whale myoglobin by replacing Leu29 and Phe43 with Glu and His, respectively (swMb L29E, F43H, H64, called Fe{sub B}Mb(-His)). A high resolution (1.65 {angstrom}) crystal structure of Cu(II)-CN{sup -}-Fe{sub B}Mb(-His) was determined, demonstrating that the unique 2-His-1-Glu metal center was successfully created within swMb. The Fe{sub B}Mb(-His) can bind Cu, Fe, or Zn ions, with both Cu(I)-Fe{sub B}Mb(-His) and Fe(II)-Fe{sub B}Mb(-His) exhibiting nitric oxide reductase (NOR) activities. Cu dependent NOR activity was significantly higher than that of Fe in the same metal binding site. EPR studies showed that the reduction of NO to N{sub 2}O catalyzed by these two enzymes resulted in different intermediates; a five-coordinate heme-NO species was observed for Cu(I)-Fe{sub B}Mb(-His) due to the cleavage of the proximal heme Fe-His bond, while Fe(II)-Fe{sub B}Mb(-His) remained six-coordinate. Therefore, both the metal ligand, Glu29, and the metal itself, Cu or Fe, play crucial roles in NOR activity. This study presents a novel protein model of NOR and provides insights into a newly discovered member of the NOR family, gNOR.

  20. Introducing a 2-His-1-Glu Nonheme Iron Center into Myoglobin Confers Nitric Oxide Reductase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.W.; Robinson, H.; Yeung, N.; Gao, Y.-G.; Miner, K. D.; Lei, L.; Lu, Y.

    2010-07-28

    A conserved 2-His-1-Glu metal center, as found in natural nonheme iron-containing enzymes, was engineered into sperm whale myoglobin by replacing Leu29 and Phe43 with Glu and His, respectively (swMb L29E, F43H, H64, called Fe{sub B}Mb(-His)). A high resolution (1.65 {angstrom}) crystal structure of Cu(II)-CN?-Fe{sub B}Mb(-His) was determined, demonstrating that the unique 2-His-1-Glu metal center was successfully created within swMb. The Fe{sub B}Mb(-His) can bind Cu, Fe, or Zn ions, with both Cu(I)-Fe{sub B}Mb(-His) and Fe(II)-Fe{sub B}Mb(-His) exhibiting nitric oxide reductase (NOR) activities. Cu dependent NOR activity was significantly higher than that of Fe in the same metal binding site. EPR studies showed that the reduction of NO to N{sub 2}O catalyzed by these two enzymes resulted in different intermediates; a five-coordinate heme-NO species was observed for Cu(I)-Fe{sub B}Mb(-His) due to the cleavage of the proximal heme Fe-His bond, while Fe(II)-Fe{sub B}Mb(-His) remained six-coordinate. Therefore, both the metal ligand, Glu29, and the metal itself, Cu or Fe, play crucial roles in NOR activity. This study presents a novel protein model of NOR and provides insights into a newly discovered member of the NOR family, gNOR.