Effect of Daily Exposure to 15 r γ Radiation on Susceptibility of Mice to Experimental Infection. ∗

Summary

1) CF-1 female mice were exposed to approximately 15 a day radiation for 9-15 weeks and challenged at intervals by intraperitoneal inoculation with graded doses of Pseudomonas aeruginosa. Comparison of LD₅₀ of irradiated and control mice in each challenge showed that between 9th and 15th weeks a slight but demonstrable increase in susceptibility to experimental infection had occurred.

2) The increase caused by accumulation of 1350 r during 15 weeks exposure was, however, very much less than that resulting from a single acute exposure to 300 r X-radiation.