Pretreatment with oxygen species increases the resistance of mammalian cells to hydrogen peroxide and gamma-rays.
Pretreatment of Chinese hamster ovary (CHO) or H4 (rat hepatoma) cells with low non-toxic doses of H2O2 or xanthine-xanthine oxidase renders the cells more resistant to the toxic effect of H2O2 and gamma-rays. This increased resistance is observed both in exponentially growing and in plateau-phase cells. Cells pretreated with xanthine-xanthine oxidase are less mutated than control cultures when challenged with ionizing radiation. The number of DNA single-strand breaks (measured by nucleoid sedimentation) induced by a high dose of gamma-rays or H2O2 is lower in cells pretreated with xanthine-xanthine oxidase compared to control cultures. However, the pretreatment does not modify the rate of DNA single-strand breaks rejoining in cells challenged with H2O2 or gamma-rays. The catalase activity is not modified in pretreated cells, but the superoxide dismutase activity is increased about 2-fold.
Laval
F
F
Groupe Radiochimie de l'ADN, Institut Gustave Roussy, Villejuif, France.
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006224:Cricetinae; D004247:DNA / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D005260:Female; D005720:Gamma Rays; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000494:pharmacology*; D008114:Liver Neoplasms, Experimental; D009154:Mutation; D010053:Ovary; D011839:Radiation, Ionizing; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism; D013866:Thioguanine / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D019820:Xanthine; D014969:Xanthine Oxidase / Q000494:pharmacology*; D014970:Xanthines / Q000494:pharmacology*
D014970:Xanthines; D019820:Xanthine; D004247:DNA; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D013866:Thioguanine