Strain Differences in Response to Whole Body Irradiation and Shielding Procedures in the Rat

¹ From the Atomic Energy Commission, Biological Effects of Irradiation Laboratory, University of Michigan, Ann Arbor, Michigan, and the Cancer Research Institute, University of California Medical Center, San Francisco, California

Over the past 3 years we have used 421 rats in studies of the protective effect of lead shields against irradiation death. Two strains of rats were used throughout these studies. The strain that was more sensitive to whole body irradiation was also the one more effectively protected by the shielding procedure. Previous work indicated that shielded tissues made some contribution to the irradiated animal which enhances its chances of survival. From the current study it is concluded that the strain in which the tissues are best able to make this type of contribution is also the one in which this contribution is most readily destroyed by irradiation.