The Effect of Oxygen on the Radiosensitivity of Growing Bone in the Tail of the Mouse

The effect of X irradiation on the growth of the tails of young mice was investigated. The animals were irradiated when seven days old, and the growth during subsequent weeks was compared with that of litter-mate control animals. The reduction in growth was found to give a reproducible index of radiation damage. The tails of groups of animals were irradiated while breathing various partial pressures of oxygen ranging from one-tenth to three atmospheres. The tails of another group were irradiated with the blood occluded to render them anoxic. In this way the variation of relative radiosensitivity of the growing mouse tail was determined for various partial pressures of oxygen in the respired gas.