Interaction of nitrogen dioxide with human plasma Antioxidant depletion and oxidative damage

Abstract

Nitrogen dioxide (NO'.,) is often present in inhaled air and ,nay be generated in viva from tfitrie oxide. Exposure of human blood plasma to NO~ caused rapid los~es of as¢orbic acid, uric acid and protein thiol groups, as well as lipid peroxidation and depletions ofcz-to¢opherol, bilirabia and ubiqninol-10. No increase in protein carbonyls was detected. $ttpplementation of plasma with ascorbate decreased the rules of lipid pero~idation, 0:-tocopherol del~letion and 1o~5 of uric acid. Uric acid supplementation decreased rat¢~ of lipid peroxidation but not the loss ofcx-toeopherol, We conclude Ihat a~corbic acid, protein -SH groups, uric a~:id and ~z-tocophcrol may be important agents protecting against NO~ in viva. If these antioxidants are depleted, peroxidation of lipids occurs and might contribute to the toxicity of NO'.,.

Oxygen-derived species: their relation to human disease and environmental stress.

“…By contrast with the effect of 03, NO0 did not generate protein carbonyls in plasma, although nitration of aromatic amino acids took place and protein -SH groups were lost, presumably by direct reaction with NO (86). Again unlike 03, NO2 induced lipid peroxidation in plasma, presumably by the reactions L-H + NO -HN02 + L [8] L-+ 02-4 LOO [9] L-H + LOO --> L + LOOH [10] Initiation of peroxidation by NOQ (Equation 8) presumably sets up the autocatalytic chain reaction of lipid peroxidation (Equations 9,10) resulting in the accumulation of lipid peroxides (LOOH).…”

“…Again unlike 03, NO2 induced lipid peroxidation in plasma, presumably by the reactions L-H + NO -HN02 + L [8] L-+ 02-4 LOO [9] L-H + LOO --> L + LOOH [10] Initiation of peroxidation by NOQ (Equation 8) presumably sets up the autocatalytic chain reaction of lipid peroxidation (Equations 9,10) resulting in the accumulation of lipid peroxides (LOOH). Uric acid and ascorbate were found to be important antioxidants protecting plasma against oxidative damage by NO;, but the lipid-soluble antioxidants ct-tocopherol and ubiquinol probably also play an important protective role in limiting lipid peroxidation (86).…”

Macrophage Activation: Role of Toll-like Receptors, Nitric Oxide, and Nuclear Factor kappa B

“…Nitrogen oxides have been shown to increase lipid peroxidation and decrease antioxidant defense systems. 25 Exposed thiol groups can react with nitric oxide and then later liberate the extremely reactive nitrosonium ion. The reaction of nitric oxide and superoxide results in the formation of peroxynitrite, a powerful oxidant.…”

Catalase polymorphism May Influence the Pathogenesis of Diabetes Mellitus

“…Unlike the superoxide ion, it can cross cell membrane boundaries and decomposes to form the reactive hydroxyl radical [15]. CAT destroys hydrogen peroxide in two steps, using a haem group in its structure.…”