Oxygen metabolism in phagocytes of leprotic patients: enhanced endogenous superoxide dismutase activity and hydroxyl radical generation by clofazimine.
AUTOR(ES)
Niwa, Y
RESUMO
We examined the generation of active oxygens (O2-, H2O2, and OH X ) and the superoxide dismutase (SOD) activity of polymorphonuclear leukocytes (PMNs) and monocytes from 14 leprotic patients manifesting a bacillary index above 2.2. Patients with disease of more than 4 years in duration showed significantly enhanced SOD activity and a decrease in O2- and OH X production. The antileprotic agent, clofazimine, significantly increased the generation of OH X in a dose-dependent manner, with a subsequent decrease in H2O2, but had no effect on the SOD activity of the PMNs and monocytes. In medium containing FeSO4 or Fe2+-EDTA, the drug elevated OH X production markedly further. Phagocytic SOD in PMNs and monocytes of leprotic patients was both host and bacillus derived, because the presence of cyanide, to which human-derived cuprozinc SOD is susceptible, did not completely abrogate SOD activity. The difficulty in treating leprosy may be partly ascribable to decreased phagocytic OH X generation, which in leprosy patients is apparently due to the uptake of Hansen bacillus-derived SOD. Clofazimine may be effective in leprosy by chelating Fe2+, with the resultant potentiation of the catalyzing activity of Fe2+ in the Haber-Weiss reaction increasing OH X formation from H2O2.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=271453Documentos Relacionados
- Endogenous Superoxide Dismutase Levels Regulate Iron-Dependent Hydroxyl Radical Formation in Escherichia coli Exposed to Hydrogen Peroxide
- Corneal changes in patients treated with clofazimine.
- Copper, zinc superoxide dismutase catalyzes hydroxyl radical production from hydrogen peroxide.
- Generation of Hydroxyl Radical by Enzymes, Chemicals, and Human Phagocytes In Vitro: DETECTION WITH THE ANTI-INFLAMMATORY AGENT, DIMETHYL SULFOXIDE
- Recombinant superoxide dismutase reduces oxygen free radical concentrations in reperfused myocardium.