Hydrogen Peroxide and the Indirect Effect of Ionizing Radiations

Abstract

IN a recent paper, Allsopp¹ has suggested that the old ‘poison' hypothesis for the action of ionizing radiation on living cells might be revived in terms of the ‘hydroxyl radical' as the specific poison. Results of experiments on bacteriophage S13, undertaken at the instigation and with the support of the late Dr. D. E. Lea, suggest that for certain in vitro experiments, at least, on the indirect effects of ionizing radiation, a poison hypothesis in quite direct terms will explain the results satisfactorily, the specific poison being hydrogen peroxide. As has been pointed out², the fact that hydrogen peroxide is formed in irradiated water itself requires explanation in terms of a theory such as that of Weiss³ ; but it has become evident that all the observed facts on ‘indirect' action of radiation on this particular phage are fitted by the explanation that when the phage is in dilute solution the hydrogen peroxide formed by ionizing radiations will inactivate it. The following results support this explanation.