The effect of the selenium-containing compounds selenomethionine, selenocystine and ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one] on the oxidation of dihydrorhodamine 123 caused by peroxynitrite and on the nitration of 4-hydroxyphenylacetate by peroxynitrite was studied in comparison with their sulphur analogues methionine, cystine and ebsulfur [2-phenyl-1,2-benzisothiazol-3(2H)-one]. The s...

In the present study, we examined the effects of peroxynitrite on reperfusion injury using a rat model of hepatic ischemia-reperfusion (HI/R). The left and median lobes of the liver were subjected to 30 min of ischemia, followed by 4 h of reperfusion. Groups A and B rats were sham-operated controls that received vehicle or peroxynitrite; groups C and D rats were subjected to HI/R and received p...

Most thymocytes are deleted by thymic selection. The mechanisms of cell death are far from being clear. Peroxynitrite is a powerful oxidant produced in vivo by the reaction of superoxide (O2) with nitric oxide (NO•) and is able to mediate apoptosis. The aim of this study was to analyze whether NO and peroxynitrite could play a role in human thymocyte apoptosis. The results indicate that 3-(4-mo...

Peroxynitrite is a potent oxidant formed by the rapid reaction of the free radicals nitric oxide (NO) and superoxide. It causes airway hyperresponsiveness and airway epithelial damage, enhances inflammatory cell recruitment, and inhibits pulmonary surfactant. Asthma is characterized by increased airway hyperresponsiveness, airway epithelial shedding, and inflammation. We examined the production...

Here we show that exogenous peroxynitrite results in nitration of phosphorylase as well inhibition glycogenolysis isolated intact mouse skeletal muscle during short-term repeated contractions. However, contractions the absence do not result or affect glycogenolysis, nor does addition antioxidants alter Thus is subject to redox control

The elevated nitric oxide/peroxynitrite and the neural sensitization theories of multiple chemical sensitivity (MCS) are extended here to propose a central mechanism for the exquisite sensitivity to organic solvents apparently induced by previous chemical exposure in MCS. This mechanism is centered on the activation of N-methyl-D-aspartate (NMDA) receptors by organic solvents producing elevated...

Peroxynitrite, a cytotoxic oxidant formed from nitric oxide (NO) and superoxide, induces DNA strand breakage, which activates the nuclear enzyme poly(ADPribose) synthase (PARS; EC 2.4.2.30). The cellular function of PARS was determined in fibroblast lines from PARS knockout animals (PARS2/2) and corresponding wild-type animals (PARS1/1), with the aid of the lipophilic PARS inhibitor 5-iodo-6-am...

An initial rate approach was used to study the reaction of peroxynitrite with human serum albumin (HSA) through stopped-flow spectrophotometry. At pH 7.4 and 37 degreesC, the second order rate constant for peroxynitrite reaction with HSA was 9.7 +/- 1.1 x 10(3) M-1 s-1. The rate constants for sulfhydryl-blocked HSA and for the single sulfhydryl were 5.9 +/- 0.3 and 3.8 +/- 0.8 x 10(3) M-1 s-1, ...

Lipid oxidation and nitration represents a novel area of research of relevance in the understanding of inflammatory processes. Peroxynitrite, the product of the diffusion-limited reaction between nitric oxide and superoxide anion, mediates oxidative modifications in lipid systems including cell membranes and lipoproteins. In this review, we discuss the mechanisms of lipid oxidation and nitratio...

We present the design, synthesis, spectroscopy, and biological applications of PyBor, a new type of fluorescent probe for peroxynitrite detection in aqueous solution and living cells. The probe employs pyrene as the fluorophore, and is equipped with a chemically responsive unit boronate. The fluorescent probe can selectively detect peroxynitrite with fluorimetric determination and high-performa...