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Journal ArticleDOI

Formation and properties of peroxynitrite as studied by laser flash photolysis, high-pressure stopped-flow technique, and pulse radiolysis.

01 Nov 1997-Chemical Research in Toxicology (American Chemical Society)-Vol. 10, Iss: 11, pp 1285-1292
TL;DR: Improvements to the biomimetic synthesis of peroxynitrite with solid potassium superoxide and gaseous nitrogen monoxide result in higher peroxlynitrite to nitrite yields than in most other syntheses.
Abstract: Flash photolysis of alkaline peroxynitrite solutions results in the formation of nitrogen monoxide and superoxide. From the rate of recombination it is concluded that the rate constant of the react...
Citations
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Journal ArticleDOI
TL;DR: An "oxidative response to inflammation" model is proposed as a means of reconciling the response-to-injury and oxidative modification hypotheses of atherosclerosis.
Abstract: This review focuses on the role of oxidative processes in atherosclerosis and its resultant cardiovascular events. There is now a consensus that atherosclerosis represents a state of heightened oxidative stress characterized by lipid and protein oxidation in the vascular wall. The oxidative modification hypothesis of atherosclerosis predicts that low-density lipoprotein (LDL) oxidation is an early event in atherosclerosis and that oxidized LDL contributes to atherogenesis. In support of this hypothesis, oxidized LDL can support foam cell formation in vitro, the lipid in human lesions is substantially oxidized, there is evidence for the presence of oxidized LDL in vivo, oxidized LDL has a number of potentially proatherogenic activities, and several structurally unrelated antioxidants inhibit atherosclerosis in animals. An emerging consensus also underscores the importance in vascular disease of oxidative events in addition to LDL oxidation. These include the production of reactive oxygen and nitrogen species by vascular cells, as well as oxidative modifications contributing to important clinical manifestations of coronary artery disease such as endothelial dysfunction and plaque disruption. Despite these abundant data however, fundamental problems remain with implicating oxidative modification as a (requisite) pathophysiologically important cause for atherosclerosis. These include the poor performance of antioxidant strategies in limiting either atherosclerosis or cardiovascular events from atherosclerosis, and observations in animals that suggest dissociation between atherosclerosis and lipoprotein oxidation. Indeed, it remains to be established that oxidative events are a cause rather than an injurious response to atherogenesis. In this context, inflammation needs to be considered as a primary process of atherosclerosis, and oxidative stress as a secondary event. To address this issue, we have proposed an "oxidative response to inflammation" model as a means of reconciling the response-to-injury and oxidative modification hypotheses of atherosclerosis.

2,518 citations

Journal ArticleDOI
TL;DR: This review examines how target selectivity and antioxidant effectiveness vary for different oxidants and highlights areas where greater understanding is required on the fate of oxidants generated by cellular NADPH oxidases and on the identification of oxidant sensors in cell signaling.
Abstract: There is a vast literature on the generation and effects of reactive oxygen species in biological systems, both in relation to damage they cause and their involvement in cell regulatory and signaling pathways. The biological chemistry of different oxidants is becoming well understood, but it is often unclear how this translates into cellular mechanisms where redox changes have been demonstrated. This review addresses this gap. It examines how target selectivity and antioxidant effectiveness vary for different oxidants. Kinetic considerations of reactivity are used to assess likely targets in cells and how reactions might be influenced by restricted diffusion and compartmentalization. It also highlights areas where greater understanding is required on the fate of oxidants generated by cellular NADPH oxidases and on the identification of oxidant sensors in cell signaling.

2,011 citations

Journal ArticleDOI
TL;DR: The levels of oxidative DNA damage reported in many human tissues or in animal models of carcinogenesis exceed the levels of lesions induced by exposure to exogenous carcinogenic compounds, and it seems likely that oxidativeDNA damage is important in the etiology of many human cancers.
Abstract: A major development of carcinogenesis research in the past 20 years has been the discovery of significant levels of DNA damage arising from endogenous cellular sources. Dramatic improvements in analytical chemistry have provided sensitive and specific methodology for identification and quantitation of DNA adducts. Application of these techniques to the analysis of nuclear DNA from human tissues has debunked the notion that the human genome is pristine in the absence of exposure to environmental carcinogens. Much endogenous DNA damage arises from intermediates of oxygen reduction that either attack the bases or the deoxyribosyl backbone of DNA. Alternatively, oxygen radicals can attack other cellular components such as lipids to generate reactive intermediates that couple to DNA bases. Endogenous DNA lesions are genotoxic and induce mutations that are commonly observed in mutated oncogenes and tumor suppressor genes. Their mutagenicity is mitigated by repair via base excision and nucleotide excision pathways. The levels of oxidative DNA damage reported in many human tissues or in animal models of carcinogenesis exceed the levels of lesions induced by exposure to exogenous carcinogenic compounds. Thus, it seems likely that oxidative DNA damage is important in the etiology of many human cancers. This review highlights some of the major accomplishments in the study of oxidative DNA damage and its role in carcinogenesis. It also identifies controversies that need to be resolved. Unraveling the contributions to tumorigenesis of DNA damage from endogenous and exogenous sources represents a major challenge for the future.

1,825 citations

Journal ArticleDOI
TL;DR: This review focuses on mechanisms for sensing and transmitting redox signals, from the perspective of their chemical reactivity with specific oxidants, and discusses substrate preferences for different oxidants and how the kinetics of these reactions determines how each oxidant will react in a cell.

1,107 citations

Journal ArticleDOI
TL;DR: Critical issues regarding this biological process, namely the biochemical pathways for nitration of tyrosine residues in vivo, potential protein targets, and pathophysiological consequences of protein tyrosines nitration are addressed.

1,015 citations

References
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Journal ArticleDOI
TL;DR: In this article, the rate constants for over 3500 reaction are tabulated, including reaction with molecules, ions and other radicals derived from inorganic and organic solutes, and the corresponding radical anions, ⋅O− and eaq−, have been critically pulse radiolysis, flash photolysis and other methods.
Abstract: Kinetic data for the radicals H⋅ and ⋅OH in aqueous solution,and the corresponding radical anions, ⋅O− and eaq−, have been critically pulse radiolysis, flash photolysis and other methods. Rate constants for over 3500 reaction are tabulated, including reaction with molecules, ions and other radicals derived from inorganic and organic solutes.

9,887 citations

Journal ArticleDOI
TL;DR: The rapid diffusion of nitric oxide between cells allows it to locally integrate the responses of blood vessels to turbulence, modulate synaptic plasticity in neurons, and control the oscillatory behavior of neuronal networks.
Abstract: Nitric oxide contrasts with most intercellular messengers because it diffuses rapidly and isotropically through most tissues with little reaction but cannot be transported through the vasculature due to rapid destruction by oxyhemoglobin. The rapid diffusion of nitric oxide between cells allows it to locally integrate the responses of blood vessels to turbulence, modulate synaptic plasticity in neurons, and control the oscillatory behavior of neuronal networks. Nitric oxide is not necessarily short lived and is intrinsically no more reactive than oxygen. The reactivity of nitric oxide per se has been greatly overestimated in vitro because no drain is provided to remove nitric oxide. Nitric oxide persists in solution for several minutes in micromolar concentrations before it reacts with oxygen to form much stronger oxidants like nitrogen dioxide. Nitric oxide is removed within seconds in vivo by diffusion over 100 microns through tissues to enter red blood cells and react with oxyhemoglobin. The direct toxicity of nitric oxide is modest but is greatly enhanced by reacting with superoxide to form peroxynitrite (ONOO-). Nitric oxide is the only biological molecule produced in high enough concentrations to out-compete superoxide dismutase for superoxide. Peroxynitrite reacts relatively slowly with most biological molecules, making peroxynitrite a selective oxidant. Peroxynitrite modifies tyrosine in proteins to create nitrotyrosines, leaving a footprint detectable in vivo. Nitration of structural proteins, including neurofilaments and actin, can disrupt filament assembly with major pathological consequences. Antibodies to nitrotyrosine have revealed nitration in human atherosclerosis, myocardial ischemia, septic and distressed lung, inflammatory bowel disease, and amyotrophic lateral sclerosis.

5,370 citations

Journal ArticleDOI
TL;DR: The results support that peroxynitrite anion rapidly reacts with carbon dioxide to yield an adduct (ONOOCO2-) which can participate in oxidation and nitration processes, thus redirecting the primary reactivity of peroxysitrite.

550 citations

Journal ArticleDOI
TL;DR: The results suggest that ONOO- can be a critical unrecognized mediator of cell-derived luminol chemiluminescence reported in previous studies, and it is shown that bicarbonate can participate in secondary oxidation reactions after reacting with ONOO-.
Abstract: Vascular endothelial cells, smooth muscle cells, macrophages, neutrophils, Kupffer cells and other diverse cell types generate superoxide (O2.-) and nitric oxide (.NO), which can react to form the potent oxidant peroxynitrite anion (ONOO-). Peroxynitrite reacted with luminol to yield chemiluminescence which was greatly enhanced by bicarbonate. The quantum chemiluminescence yield of the ONOO- reaction with luminol in bicarbonate was approx. 10(-3). Chemiluminescence was superoxide dismutase-inhibitable, indicating that O2.- was a key intermediate for chemiexcitation. O2.- appears to be formed secondarily to the reaction of a bicarbonate-peroxynitrite complex with luminol, yielding luminol radical and O2.-. Luminol radical reacts with O2.- to form the unstable luminol endoperoxide, which follows the light-emitting pathway. Neither .NO nor O2.- alone were capable of directly inducing significant luminol chemiluminescence in our assay systems. These results suggest that ONOO- can be a critical unrecognized mediator of cell-derived luminol chemiluminescence reported in previous studies. In addition, it is shown that bicarbonate can participate in secondary oxidation reactions after reacting with ONOO-.

360 citations