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Plasma GSH and GSSG concentrations were examined after the administration of compounds that deplete intracellular GSH either by adduct formation or by production of oxidative stress. A modified assay based on the GSSG reductase method was developed that minimizes the artifactual auto-oxidation of GSH to GSSG and mixed disulfides by rapid addition of(More)
The mainstream and sidestream smoke of four types of popular US cigarettes were analyzed for toxic and carcinogenic agents. The cigarettes included one without a filter tip, and one filter cigarette each with medium, low and ultra-low smoke yields. The analyses clearly demonstrated that 12 toxic agents determined in this study were significantly reduced in(More)
Human data indicate an increased risk for cancer of the oral cavity for snuff dippers. Popular snuff products from the United States, Germany, Sweden, and Denmark were analyzed for tobacco-specific N-nitrosamines (TSNA). These compounds are formed during tobacco processing from nicotine, nornicotine, and anatabine and represent the only known carcinogens in(More)
MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) produces an irreversible parkinsonism in primates. Recent evidence suggests metabolism of MPTP to 1-methyl-4-phenylpyridine (MPP+) is required for toxicity. We have proposed that MPP+ may play a central role in the toxicity of MPTP, but direct assessment of the effects of MPP+ in brain is difficult.(More)
The pharmacokinetics of N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the Syrian golden hamster, the CD-1 mouse, and the baboon were compared to the pharmacokinetics in the Fischer rat. The formation and biological half-life of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), the major metabolite of NNK, was(More)
The involvement of oxygen radicals in the pathogenesis of Parkinson's disease has been suggested for some time. This article reviews the evidence supporting the involvement of oxygen radicals in the disease process in the brain. This includes a discussion of iron, lipid peroxidation, peroxidase, catalase, superoxide dismutase, and glutathione levels in the(More)
The mechanism of acrolein-induced lipid peroxidation is unknown. This study found that acrolein and its glutathione adduct, glutathionylpropionaldehyde, induce oxygen radical formation. These oxygen radicals may be responsible for the induction of lipid peroxidation by acrolein. The enzymes xanthine oxidase and aldehyde dehydrogenase were found to interact(More)
The tumorigenic activities toward the oral cavity of snuff, its extracts, and two of its major nitrosamines, N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were evaluated in male F344 rats. In one protocol, groups of 21-30 rats were treated beginning at age 10 weeks by chronic application to the oral cavity for 131(More)
An ultrasensitive HPLC method has been developed for measuring NADP+, NADPH, NAD+, and NADH. A simple, rapid reaction of the oxidized nucleotides with cyanide in basic solution leads to two stable fluorescent products and allows all four nucleotides to be separated and quantitated on one chromatogram. Furthermore, only one extraction is needed, rather than(More)
Hepatic glutathione turnover and the efflux of glutathione from the liver into bile and blood were measured in male Sprague-Dawley rats in vivo. In fed rats the efflux of glutathione into blood, calculated from the hepatic arteriovenous concentration gradient and hepatic blood flow, amounted to 12.4 +/- 1.4 nmoles min X gm liver. Together with the excretion(More)