We evaluate herein the impact of positive charge distribution on the in vitro and in vivo properties of Mn porphyrins as redox modulators possessing the same overall 5+ charge and of minimal stericity demand: Mn(III) meso-tetrakis(trimethylanilinium-4-yl)porphyrin (MnTTriMAP(5+)), Mn(III) meso-tetrakis(N,N'-dimethylpyrazolium-4-yl)porphyrin (MnTDM-4-PzP(5+)), Mn(III) meso-tetrakis(N,N'-dimethyl...

Nitroxides are the most important metal-independent superoxide dismutase mimics. They act as antioxidants mainly by reacting with superoxide. Nitroxides are low molecular weight, cell membrane permeable, and relatively stable radicals. The SOD-mimic activities of nitroxides are catalytic processes in which nitroxides and their oxidized form exchange among themselves without depletion of nitroxi...

Hypothermic perfusion of the heart decreases oxidative phosphorylation and increases NADH. Because O(2) and substrates remain available and respiration (electron transport system, ETS) may become impaired, we examined whether reactive oxygen species (ROS) exist in excess during hypothermic perfusion. A fiberoptic probe was placed on the left ventricular free wall of isolated guinea pig hearts t...

The Mn(III) meso -tetrakis(N-ethylpyridinium-2-yl)porphyrin, MnIIITE-2PyP5+, is a potent SOD mimic in vitro, and was beneficial in rodent models of oxidative stress pathologies. Its high activity has been ascribed to both the favorable redox potential of its metal center and to the electrostatic facilitation assured by the four positive charges encircling the metal center. Its comparison with t...

The tobacco alkaloid nicotine possesses a molecular structure by which it may be related empirically to the amino acid proline. Proline is a-pyrrolidinecarboxylic acid. Nicotine may be considered as an N-methylated proline containing a 3-pyridine rino attached to the alpha position in place of the carboxyl. These similarities have been pointed out by TOTTINGHAM (9) and have been employed by TRI...

A novel dissimilatory perchlorate-reducing bacterium (DPRB), Arcobacter sp. strain CAB, was isolated from a marina in Berkeley, CA. Phylogenetically, this halophile was most closely related to Arcobacter defluvii strain SW30-2 and Arcobacter ellisii. With acetate as the electron donor, strain CAB completely reduced perchlorate (ClO4(-)) or chlorate (ClO3(-)) [collectively designated (per)chlora...

To examine the structural identities of reactive free radicals and the mechanism of the oxidative modification of proteins, we used EPR and spin-trapping methods to investigate the oxidation of amino acids by H2O2 as well as the decomposition of H2O2 itself catalyzed by Mn(II) ions. Superoxide and hydroxyl radicals (O2-. and OH.) were trapped by a spin trap, 5,5-dimethyl-1-pyrroline-1-oxide (DM...