A novel approach to measure the time course of paramagnetic spin probe concentration in the circulating blood of a living mouse using X-band (9.4 GHz) electron paramagnetic resonance spectrometer is described. Using this technique, the pharmacokinetics of several nitroxyl spin probes was examined. The decay profiles were also independently simulated using pharmacokinetic properties as well as r...

Urinary N-hydroxy metabolites of the bladder carcinogens, 2-aminofluorene and 4-aminobiphenyl, were examined for the induction of unscheduled DNA synthesis (UDS) in urothelial cells of several susceptible species. N-Hydroxy-2-aminofluorene, N-hydroxy-2-acetylaminofluorene (N-OH-AAF), N-hydroxy-4-aminobiphenyl, N-hydroxy-4-acetylaminobiphenyl, and the N-glucuronides of these two hydroxylamines i...

3-Amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) are potent mutagen/carcinogens isolated from pyrolyzates of tryptophan and glutamic acid, respectively, and they have been found to exist in many cooked foods. Trp-P-2 and Glu-P-1 bind to DNA covalently after metabolic activations. The compounds are oxidized to the corresponding hydr...

Nitroxides can undergo one- or two-electron reduction reactions to hydroxylamines or oxammonium cations, respectively, which themselves are interconvertible, thereby providing redox metabolic actions. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) is the most extensively studied nitroxide. It is a cell membrane-permeable amphilite that dismutates superoxide catalytically, facilitates h...

The role of hydrogenase on the reduction of 2,4,6-trinitrotoluene (TNT) in Clostridium acetobutylicum was evaluated. An Fe-only hydrogenase was isolated and identified by using TNT reduction activity as the selection basis. The formation of hydroxylamino intermediates by the purified enzyme corresponded to expected products for this reaction, and saturation kinetics were determined with a K(m) ...