Influence of Altered Atmospheric Oxygen on Urethan-Induced Pulmonary Tumors in Mice

Abstract

Three groups of male and female Strong A mice, 6 to 8 weeks old, were injected with either 0.01 mg., 0.1 mg., or 1.0 mg. of urethan per gm. of body weight. Immediately after injection, mice from each of the 3 groups were exposed for 48 hours to 4 different environments: 10 percent oxygen, room air, 70 percent oxygen, and compressed air. Three months later the mice were killed and the number of pulmonary adenomas counted. With 1 mg. of urethan per gm. of body weight, the concentration which produced tumors in all mice, the hyperoxia group developed more tumors than the other groups and showed a statistically significant difference from the other groups.