Modification of Urethan-Lung Tumor Incidence by Low X Radiation Doses. Cortisone and Transfusion of Isogenic Lymphocytes

摘要

Young adult male LAF1 mice were exposed to a single (300 R) dose of X rays, followed one day later by an intraperitoneal injection of urethan, 0.08 mg or 0.2 per gram body weight Cortisone acetate was injected subcutaneously, 7 injections of 2.5 mg each, on alternate days beginning one day after irradiation. The mice were sacrificed 25 to 26 weeks after the urethan injection, and the enumeration of lung tumor incidence was made by standard procedures. The percent of mice bearing lung tumors was highest (50%) in the group receiving 300 R plus urethan (0108 mg/g), as compared with 12.5% in the control mice irradiated only, and 16% in those receiving urethan only. Thus, X radiation and urethan can be additive for lung tumorigenesis. (Author)