Human extracellular superoxide dismutase (EC-SOD; EC 1.15.1.1) is a scavenger of superoxide anions in the extracellular space. The amino acid sequence is homologous to the intracellular counterpart, Cu/Zn superoxide dismutase (Cu/Zn-SOD), apart from N- and C-terminal extensions. Cu/Zn-SOD is a homodimer containing four cysteine residues within each subunit, and EC-SOD is a tetramer composed of ...

Generation of superoxide and hydrogen peroxide during interaction of nitrite with human hemoglobin was detected by chemiluminescence of luminol. Luminol chemiluminescence was inhibited by the addition of superoxide dismutase (SOD) and catalase. Methemoglobin formation induced by nitrite was also inhibited by the addition of SOD and catalase. The mechanism of methemoglobin formation by nitrite w...

The superoxide radical (O(2)(-)) has long been considered a major cause of aging. O(2)(-) in cytosolic, extracellular, and mitochondrial pools is detoxified by dedicated superoxide dismutase (SOD) isoforms. We tested the impact of each SOD isoform in Caenorhabditis elegans by manipulating its five sod genes and saw no major effects on life span. sod genes are not required for daf-2 insulin/IGF-...

Exposure to hypobaric hypoxia causes oxidative damage to male rat reproductive function. The aim of this study was to evaluate the protective effect of a blueberry extract (BB-4) in testis of rats exposed to hypobaric hypoxia. Morphometric analysis, cellular DNA fragmentation, glutathione reductase (GR), and superoxide dismutase (SOD) activities were evaluated. Our results showed that supplemen...

A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the...

The production of superoxide (O2-) under hyperoxic conditions is markedly accentuated leading to the generation of potent oxidants such as hydrogen peroxide (H2O2), hydroxyl radical (HO.), and peroxynitrite (ONOO-). Superoxide dismutase (SOD), by rapidly removing O2-, reduces the tissue concentration of O2- and prevents the production of HO. and ONOO-. Three forms of SOD exist in the lung: CuZn...

Introduction: The gastrointestinal system is frequently affected in patients with diabetes mellitus (DM). Some of these alterations are due to oxidative stress and the production of free radicals. The present study was designed to evaluate whether treatment with superoxide dismutase (SOD) exerts protection on established bowel alterations in experimental diabetes mellitus induced by streptozoto...