The Relative Biologic Effectiveness Of X Rays Gamma Rays And Fast Neutrons In The Production Of Weight Loss Of The Small Intestine Of The Mouse PDF Download

Groups of 10-week-old female RF mice were exposed to graded doses of Cobalt-60 gamma rays, 250-kvp x-rays, or 14-Mev fast neutrons. The weight of the small intestine decreased during the first 48 hours after irradiation as a linear function of dose over the range of 50 to 700 Rads. No significant differences between radiations in the production of this effect was observed 1 day after irradiation, but at 2 days the RBE was found to increase with LET, being 1.0, 1.5, and 2.0 for gamma rays, x-rays and neutrons, respectively. The RBE of neutrons for intestinal weight loss was appreciably higher than for 30-day lethality, in keeping with the hypothesis that the earlier mortality of mice exposed to neutrons, as opposed to x-rays, results from relatively greater injury of the gastrointestinal tract by neutrons.