Free radicals and inflammation. Protection of phagocytosine leukocytes by superoxide dismutase.

Free radicals and inflammation. Protection of phagocytosine leukocytes by superoxide dismutase.

Isolated human polymorphonuclear leukocytes engaged in phagocytosis liberate superoxide radical and hydrogen peroxide into the surrounding medium. These two chemical species react to produce the hydroxyl radical, which attacks the leukocyte and leads to premature death of the cell. The hydroxyl radical may be scavenged by mannitol, or its formation can be prevented by the addition of superoxide...

Superoxide dismutase activity in leukocytes.

Superoxide dismutase activity has been identified in both human neutrophils and rabbit alveolar macrophages by two distinct assay procedures. The enzyme is insensitive to both cyanide and azide and is present in the cytosol of the cell. The identification of this enzyme in phagocytic cells is compatible with the theory that superoxide anion might be involved in the bactericidal activity of the ...

Superoxide dismutase Superoxide dismutase

Mitochondrial complex I deficiency leads to increased production of superoxide radicals and induction of superoxide dismutase.

Mitochondria were isolated from skin fibroblast cultures derived from healthy individuals (controls) and from a group patients with complex I (NADH-CoQ reductase) deficiency of the mitochondrial respiratory chain. The complex I deficient patients included those with fatal infantile lactic acidosis (FILA), cardiomyopathy with cataracts (CC), hepatopathy with tubulopathy (HT), Leigh's disease (LD...

Free radicals and inflammation: superoxide-dependent activation of a neutrophil chemotactic factor in plasma.

The intravenous administration of superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) to animals with induced inflammation suppresses the inflammatory response and inhibits leukocyte infiltration into the challenged site, suggesting that neutrophil-generated superoxide reacts with an extracellular precursor to generate a substance chemotactic for neutrophils. Plasma exposed...