Introduction Damage via generation of free radicals has been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Numerous studies demonstrate both direct and surrogate evidence for a high burden of oxidative and nitrative stress which parallels disease activity. Antioxidants such as superoxide dismutase (SOD) function to protect against oxidative damage by neutralizing free ra...

The major unexplained phenomenon in fibrotic conditions is an increase in replicating fibroblasts. In this report we present evidence that oxygen free radicals can both stimulate and inhibit proliferation of cultured human fibroblasts, and that fibroblasts themselves release superoxide (O2.-) free radicals. Fibroblasts released O2.- in concentrations which stimulated proliferation, a finding co...

A unified theory of cell division is presented. This theory explains the division of both tumor cells and normal cells and involves superoxide radicals, hydrogen peroxide, glucose, cAMP, and cGMP.

The stimulatory effect of ferrous salts on the peroxidation of phospholipids can be enhanced by EDTA when the concentration of Fe2+ in the reaction is greater than that of EDTA. Hydroxyl-radical scavengers do not inhibit peroxidation until the concentrations of Fe2+ and EDTA in the reaction are equal. Lipid peroxidation is then substantially initiated by hydroxyl radicals derived from a Fenton-...

Redox reactions play key roles in intra- and inter-cellular signaling, and in adaptative processes of tissues towards stress. Among the major free radicals with essential functions in cells are reactive oxygen species (ROS) including superoxide anion (O2 (•-)), hydroxyl radical ((•)OH) and reactive nitrogen species (RNS) such as nitric oxide ((•)NO). In this article, we review the forgotten and...

In recent years, there has been an explosion of interest in the involvement of free radicals in carcinogenesis (1 -4) . This seems a natural outgrowth of the long overdue realization that free radicals are formed in biological systems and that they contribute significantly to physiological and pathological processes. Much of the emphasis of research linking free radicals and cancer has focused ...

Superoxide dismutase has been purified to homogeneity from aerobically grown Thiobacillus denitrijicarzs strain “RT”. It has a molecular weight of 43,000, is composed of two identical subunits which are not covalently bound, and contains 1.35 atom of iron per molecule. Absorption spectra and amino acid analysis are similar to those of other Fe-superoxide dismutases from bacteria. Aerobically an...

Aging is characterized by increased oxidative stress, chronic inflammation, and organ dysfunction, which occur in a progressive and irreversible manner. Superoxide dismutase (SOD) serves as a major antioxidant and neutralizes superoxide radicals throughout the body. In vivo studies have demonstrated that copper/zinc superoxide dismutase-deficient (Sod1(-/-)) mice show various aging-like patholo...

Contractions of skeletal muscles produce increases in concentrations of superoxide anions and activity of hydroxyl radicals in the extracellular space. The sources of these reactive oxygen species are not clear. We tested the hypothesis that, after a demanding isometric contraction protocol, the major source of superoxide and hydroxyl radical activity in the extracellular space of muscles is mi...