title: Detection of oxidant-induced slight chromosomal damage in cells by subsequent exposure to X-rays.
abstract: We examined whether slight oxidative stress and/or damage in cells could be amplified by subsequent ionizing irradiation and thus become detectable as obvious chromosomal damage. WIL2-NS cells, a human B lymphoblastoid cell line, were pretreated with an oxidant and then exposed to X-rays at 0.25 or 0.5 Gy. The chromosomal damage in the cells was evaluated by cytokinesis-block micronucleus (CBMN) assay. Pretreatment with a superoxide-generating system (hypoxanthine (HX)/xanthine oxidase (XO), 1 and 2 mU/ml of XO), tert-butyl hydroperoxide (t-BuOOH, 10 and 100 microM) or H2O2 (5 microM) alone did not induce significant chromosomal damage, but the oxidant-induced damage increased significantly with subsequent irradiation. The tested dose of these oxidants did not induce significant changes in cell viability, the nuclear division index, and the concentration of antioxidants, indicating that only weak oxidative stress was introduced into the cells. These results suggest that low-dose oxidant-induced chromosomal damage becomes detectable as obvious chromosomal damage with subsequent ionizing irradiation in vitro.
authors.affiliation: Department of Food Science Research for Health, National Institute of Health and Nutrition, Tokyo, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Sugisawa
authors.forename: Keizo
authors.initials: K
authors.lastname: Umegaki
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002467:Cell Nucleus / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D019457:Chromosome Breakage; D003849:Deoxyguanosine / Q000031:analogs & derivatives*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D015162:Micronucleus Tests; D016877:Oxidants / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D014407:Tumor Cells, Cultured; D014810:Vitamin E / Q000378:metabolism; D014965:X-Rays; D020122:tert-Butylhydroperoxide / Q000633:toxicity
chemical_list: D000975:Antioxidants; D016877:Oxidants; D017382:Reactive Oxygen Species; D013481:Superoxides; D014810:Vitamin E; D000080242:8-Hydroxy-2'-Deoxyguanosine; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D003849:Deoxyguanosine; D001205:Ascorbic Acid