Biological effects of active oxygen on an X-ray-sensitive mutant mouse cell line (SL3-147).

The biological effects of active oxygen species were examined in a mutant mouse cell line (SL3-147) that is deficient in the repair of DNA double-strand breaks. This mutant cell line shows different sensitivities to X-rays, hydrogen peroxide, paraquat and menadione when compared to the wild-type cell line (LTA). SL3-147 was more sensitive to X-rays, hydrogen peroxide and paraquat, but was less sensitive to menadione in side by side comparisons to LTA cells. The greater number of DNA double-strand breaks in SL3-147 appears to account for the line's greater sensitivity to X-rays and paraquat. DNA damage other than double-strand breaks or injury to non-DNA targets, however, is responsible for the differences between LTA and SL3-147 in their sensitivities to hydrogen peroxide and menadione.