Abstract
The interaction of nitrogen mustard (HN2) and X-radiation in the induction of lethality in cultured mammalian cells was investigated by testing the effect of HN2 pretreatment on the form of X-ray survival curves, and vice versa. It was found that, whereas the survivors to a single dose of X-radiation were sensitized to HN2, no synergistic interaction could be detected when HN2 was used as the sensitizing agent. In addition, a subline with increased chromosome number, shown to be resistant to HN2, did not display cross-resistance to X-radiation. The results are interpreted as indicating that the lethal effects of HN2 and X-radiation are not entirely due to the same mechanism.