title: Single-strand DNA breaks in rodent and human cells produced by superoxide anion or its reduction products.
abstract: Chinese hamster ovary cells and human P3 teratocarcinoma cells were exposed to superoxide anion (O2-) generated by the addition of potassium superoxide (KO2). DNA from the cells was examined by alkaline elution techniques for the production of single-strand breaks, as well as for the production of double-strand breaks and DNA-protein cross-links. It was demonstrated that KO2 produced only single-strand breaks in DNA in both cell lines, in a dose-dependent manner. The number of breaks was reduced by the prior addition of a metal chelator, indicating that some of the breaks may have been caused by the metal-catalyzed (Fenton reaction) reduction products, hydrogen peroxide or hydroxyl radical Catalase almost completely inhibited break induction by O2-, evidence for a role of hydrogen peroxide. The results of this study indicate that O2- and its reduction products can damage intracellular mammalian DNA.
authors.affiliation: Division of Biological and Medical Research, Argonne National Laboratory, IL 60439-4833.
authors.forename: M L
authors.initials: ML
authors.lastname: Cunningham
authors.forename: J G
authors.initials: JG
authors.lastname: Peak
authors.forename: M J
authors.initials: MJ
authors.lastname: Peak
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D002460:Cell Line; D004249:DNA Damage; D004260:DNA Repair; D006801:Humans; D010084:Oxidation-Reduction; D004369:Pentetic Acid / Q000494:pharmacology; D013481:Superoxides / Q000037:antagonists & inhibitors; D014965:X-Rays
chemical_list: D013481:Superoxides; D004369:Pentetic Acid; D002374:Catalase