Some Aspects of Synergistic Actions of Halogenophenols on Radiation Lethal Effect

Data concerning synergistic actions of halogenophenols to increase the radiation lethal effect on E. coli are presented in succession of the preceding paper. The synergistic actions of these reagents were greatly depressed by the addition of certain organic materials or freezing during irradiation. These results suggest that indirect actions of ionizing radiations may play an important role in the halogenophenol actions. After-effects of the irradiated reagents were also observed and the magnitude of significance of the after-effect appeared to be varied with difference in chemical structures of halognophenols. Some discussions concerning their mode of action and mechanism of the enhancement were made. It was postulated that their synergistic effects during irradiation may due to the actions of short-life free radicals and long-life species produced by the radiolysis of halogenophenol and also to some radiation damages within cells.