Induction of chromosomal aberrations in active oxygen-generating systems. I. Effects of paraquat in Chinese hamster cells in culture.
A possible role for the superoxide anion radical (O2-) in the clastogenicity of paraquat (PQ) was investigated in cultured Chinese hamster cells. When cells were treated with 0.8 mg/ml of PQ for 3 h followed by 21 h of recovery time, structural chromosome aberrations were induced in about 50% of the metaphases examined. Almost all aberrations were of the chromatid-type and involved exclusively gaps and breaks. The induction of chromosomal aberrations by PQ was enhanced by a 1-h pretreatment with diethyldithiocarbamate, an inhibitor of superoxide dismutase. Diethyl maleate, a glutathione scavenger, also enhanced the induction of chromosomal aberrations, but 3-aminotriazole, an inhibitor of catalase, showed no such effects. Enhanced induction of chromosomal aberrations was also observed when PQ-treated cells were cultured at a high oxygen concentration (80%). The present results suggest that the production of chromosomal aberrations by PQ may be directly or indirectly related to the generation of O2-, but not to the formation of hydrogen peroxide by the dismutation reaction of O2- or of other active oxygen species including the hydroxyl radical and singlet oxygen.
Sofuni
T
T
Division of Mutagenesis, National Institute of Hygienic Sciences, Tokyo, Japan.
Ishidate
M
M
D000640:Amitrole / Q000494:pharmacology; D000818:Animals; D002374:Catalase / Q000494:pharmacology; D002460:Cell Line; D002869:Chromosome Aberrations; D006224:Cricetinae; D003412:Cricetulus; D004050:Ditiocarb / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007700:Kinetics; D008298:Maleates / Q000494:pharmacology; D010269:Paraquat / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000494:pharmacology
D008298:Maleates; D004050:Ditiocarb; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; C014476:diethyl maleate; D010269:Paraquat; D000640:Amitrole