Chromosomal aberrations in V79 cells induced by superoxide radical generated by the hypoxanthine-xanthine oxidase system

The effect of the superoxide radical, generated by the hypoxanthine-xanthine oxidase system, on chromosomal mutation was examined in Chinese hamster V79 cells. When cells were treated with this system for 1 h in Hanks' solution, the incidence of metaphases with chromosomal aberrations was increased with hypoxanthine at concentrations of 2.5 to 10 micrograms/ml. On the other hand, in Eagle's minimum essential medium (MEM) or MEM supplemented with 10% fetal bovine serum, only hypoxanthine at 5 micrograms/ml plus xanthine oxidase induced chromosomal aberrations and higher concentrations of hypoxanthine were cytotoxic to V79 cells. The increased frequency of chromosomal aberrations and the cytotoxicity of hypoxanthine plus xanthine oxidase were not affected by superoxide dismutase, but were strongly inhibited by catalase.