Absorption spectra and reaction kinetics of NO2, N2O3, and N2O4 in aqueous solution

Treinin, A.; Hayon, E.

doi:10.1021/ja00723a001

Cited by 207 publications

(123 citation statements)

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“…One notes again that the induction time for detection of this oxidant was ∼2 h shorter for the CRL-2278 cells, consistent with its generation by induced O 2 -consuming enzymatic systems other than iNOS and COX-2. This oxidant was stable, as was established by separating the supernatant medium from the cells prior to applying the Amplex® Red/HRP assay; this demonstration excludes the possibility that the oxidant was NO 2 · or peroxynitrite-derived oxidants, which are very short-lived under the experimental conditions (t 1/2 < 10 s) (20,48,61). The oxidant is most likely H 2 O 2 , given its membrane permeability (62,63) and the high selectivity (64) of HRP for this peroxide.…”

Section: (B) Superoxide Generation-immediately Following Activation Omentioning

confidence: 81%

“…Sequential induction of LOX, iNOS, and COX-2 could lead to development of bactericidal potential within the cell by arginine and lipid autoxidation to generate NO 2 · in the manner suggested in Scheme 1. In this hypothetical scheme, (1) LOX functions to generate lipid hydroperoxides from reaction of O 2 with endogenous lipids (72) for (2) activation of and use by COX-2 (71) in reactions with NO 2 -(3) formed by iNOS-catalyzed arginine oxidation by O 2 (52) and subsequent aerobic oxidation of NO · (61). Recent studies have revealed a complex interaction between iNOS and COX-2, which may involve physical association of the two enzymes (73), COX-2 catalyzed consumption of NO · (16), modification of COX-2 activity via S-nitrosylation (73), and possibly inactivation of COX-2 by radical coupling of its essential tyrosyl radical with iNOS-generated NO · (74).…”

Section: Physiological Implicationsmentioning

confidence: 99%

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Pathways for Intracellular Generation of Oxidants and Tyrosine Nitration by a Macrophage Cell Line

2007

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Two transformed murine macrophage cell lines (RAW 264.7 ATCC TIB-71 and CRL-2278) were examined for oxidant production at various times following activation by using a set of fluorescence and ESR-active probes. Stimulation with a soluble agonist or activation with bacterial lipopolysaccharide plus γ-interferon caused only very small initial increases in O 2 consumption above basal rates; however, at 2-4 h post-activation, respiration increased to 2-3 fold and remained at these elevated levels over the subsequent lifetime of the cell (20-30 h). Oxidation reactions were confined primarily within the cell, as was demonstrated by using phagocytosable dichlorodihydrofluorescein-conjugated latex beads and cyclic hydroxylamines with differing membrane permeabilities. From the intrinsic reactivities of these probes and the time course of their oxidations, one infers induction of apparent peroxidase activity beginning at ∼2 h post-activation, coinciding with the increase in overall respiratory rate; this acquired capability was accompanied by accumulation of a stable horseradish peroxidase-reactive oxidant, presumably H 2 O 2 , in the extracellular medium,. Nitrite ion rapidly accumulated in the extracellular medium over a period of 5-8 h post-activation in both cell lines, indicating the presence of active nitric oxide synthase (iNOS) during that period. Prostaglandin endoperoxide H synthase (COX-2) activity was detected at 15-20 h post-activation by use of sensitive peroxide assay in conjunction with a COX-2 specific inhibitor (DuP-697). Superoxide formation was detected by reaction with hydroethidine within the first hour following activation, but not thereafter. Consistent with the absence of significant respiratory stimulation, the amount of O 2 ·-formed was very small; comparative reactions of cyclic hydroxylamine probes indicated that virtually none of the O 2 ·-was discharged into the external medium. Myeloperoxidase (MPO) activity was probed at various times post-activation by using fluorescein-conjugated polyacrylamide beads, which efficiently trap MPO-generated HOCl in neutrophils to give stable chlorofluorescein products. However, chlorination of the dye was not detected under any conditions in RAW cells, virtually precluding MPO involvement in their intracellular reactions. This same probe was used to determine changes in intraphagosomal pH, which increased slowly from ∼6.5 to ∼8.2 over a 20 h post-phagocytosis period. The cumulative data suggest activation is followed by sequential induction of an endogenous peroxidase, iNOS, and COX-2, with NADPH oxidase-derived O 2 ·-playing a minimal role in direct generation of intracellular oxidants. To account for reported observations of intracellular tyrosine nitration late in the life cycles of macrophages, we propose a novel mechanism wherein iNOS-generated NO 2 -is used by COX-2 to produce NO 2 · as a terminal microbicidal oxidant and nitrating agent.The existence of motile phagocytic cells involved with host defense in higher organisms has been known sin...

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Section: (B) Superoxide Generation-immediately Following Activation Omentioning

confidence: 81%

Section: Physiological Implicationsmentioning

confidence: 99%

Pathways for Intracellular Generation of Oxidants and Tyrosine Nitration by a Macrophage Cell Line

2007

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“…3, which were obtained from fast flow mixing of bicarbonate and peroxynitrite solutions as described in the legend to the figure. nitrite (reaction 9) (33)(34)(35). Under the same conditions as shown in Fig.…”

Section: Table I Epr Parameters Of the Carbonate Radical In Various Mmentioning

confidence: 96%

Direct EPR Detection of the Carbonate Radical Anion Produced from Peroxynitrite and Carbon Dioxide

Bonini¹,

Radí²,

Ferrer-Sueta

et al. 1999

Journal of Biological Chemistry

295

220

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The biological effects of peroxynitrite have been recently considered to be largely dependent on its reaction with carbon dioxide, which is present in high concentrations in intra-and extracellular compartments. Peroxynitrite anion (ONOO ؊ ) reacts rapidly with carbon dioxide, forming an adduct, nitrosoperoxocarboxylate (ONOOCO 2 ؊ ), whose decomposition has been proposed to produce reactive intermediates such as the carbonate radical (CO 3 . ). Here, by the use of rapid mixing continuous flow electron paramagnetic resonance (EPR), we directly detected the carbonate radical in flow mixtures of peroxynitrite with bicarbonate-carbon dioxide over the pH range of 6 -9. The radical was unambiguously identified by its EPR parameters (g ‫؍‬ 2.0113; line width ‫؍‬ 5.5 G) and by experiments with bicarbonate labeled with 13 C. In this case, the singlet EPR signal obtained with 12 C bicarbonate splits into the expected doublet because of 13 C (a( 13 C)‫؍‬ 11.7 G). The singlet spectrum of the unlabeled radical was invariant between pH 6 and 9, confirming that in this pH range the detected radical is the carbonate radical anion (CO 3 . ).Importantly, in addition to contributing to the understanding of nitrosoperoxocarboxylate decomposition pathways, this is the first report unambiguously demonstrating the formation of the carbonate radical anion at physiological pHs by direct EPR spectroscopy.Peroxynitrite 1 is formed from the very fast reaction between nitric oxide and superoxide anion (k ϭ (6.7 Ϫ 19) ϫ 10 9 M Ϫ1 s Ϫ1 ) (see Reaction 1) (1, 2). The compound is a potent oxidant that has been receiving increasing attention as a potential pathogenic mediator in human diseases and as a cellular toxin in host defense mechanisms against invading microorganisms (3-6). At present, a significant part of the biological reactivity of peroxynitrite is ascribed to the adduct produced by its reaction with carbon dioxide (7-13). The peroxynitrite anion (ONOO Ϫ ), which is the predominant form at physiological pHs (pK a ϭ 6.8) (see reaction 2, Table II) (2, 3), reacts fast with carbon dioxide (pH-independent k ϭ 5.8 ϫ 10 4 M Ϫ1 ⅐ s Ϫ1 at 37°C) (11), producing an adduct whose structure is proposed to be ([ONOOCO 2 ] Ϫ , nitrosoperoxocarboxylate) (see reaction 3, Table II) (7). Taking into account the concentrations of carbon dioxide in equilibrium with bicarbonate present in physiological fluids, model calculations have suggested that most of the peroxynitrite that might be formed in these fluids will produce the carbon dioxide adduct before reacting with other biological targets (5, 13).Carbon dioxide modulates the reactivity of peroxynitrite by altering reaction rates, product yields, and product distribution (7-13). In these reactions, formation of the adduct nitrosoperoxocarboxylate is rate-limiting, as first proposed by Lymar and Hurst (7). This suggestion was confirmed by other authors (8 -13), and the current proposal is that in the absence of substrates, the carbon dioxide adduct decomposes to nitrate and carbon dioxide, but in ...

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“…Calibration curves were constructed using solutions of NaNO 2 of known concentrations (2-50 nM) in bidistilled water. The concentration of the stock solution was controlled assuming the coefficient of molar absorption of nitrite to be 2,400 M −1 cm −1 at 230 nm [24].…”

Section: Determination Of Nitrite By Means Of 23-diaminonaphthalene mentioning

confidence: 99%

Heat-induced formation of nitrogen oxides in water

2013

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It was found by the fluorimetric method using 2,3-diaminonaphthalene that moderate heating of water (60-80 • C, for up to 4 h) leads to the fixation of atmospheric nitrogen with the formation of nitrite. The kinetic parameters of this process were determined. The energy of activation of NO − 2 formation was estimated to be 139 kJ/mol. It was found that the amount of nitrite formed depends on the concentration of dissolved oxygen and nitrogen. It was shown by two independent methods (Griess reagent/VCl 3 and 2,3-diaminonaphthalene/nitrate reductase) that heating of water (80 • C, 1 h) results in the formation of nitrate; with the use of the fluorescent probe dihydrorhodamine 123, the generation of nitrogen dioxide (peroxynitrite) was revealed. Nitrite, nitrate, and nitrogen dioxide are formed in water upon heating in approximately equal amounts. A scheme of reactions proceeding with bidistilled water by the action of heat with the formation of nitrogen oxides is proposed.

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Absorption spectra and reaction kinetics of NO2, N2O3, and N2O4 in aqueous solution

Cited by 207 publications

References 0 publications

Pathways for Intracellular Generation of Oxidants and Tyrosine Nitration by a Macrophage Cell Line

Pathways for Intracellular Generation of Oxidants and Tyrosine Nitration by a Macrophage Cell Line

Direct EPR Detection of the Carbonate Radical Anion Produced from Peroxynitrite and Carbon Dioxide

Heat-induced formation of nitrogen oxides in water

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