The Effect of X-Irradiation on Sodium and Water Transport in Rat Ileum

Abstract

X-ray doses of 2500 to 3000 rads were administered to the abdomen of rats, and sodium and water transport by the ileum were studied in vivo at postirradiation times ranging from 6 to 67 hours. Sodium and water were rapidly absorbed from the lumen in control nonirradiated animals. Six hours after irradiation net absorption was considerably reduced, and in the period from 13 to 48 hours there was no net transfer of either Sodium or water across the mucosa, Thirteen hours after irradiation normal active transport of sodium from lumen to plasma was stopped. Unidirectional sodium fluxes were lower than those in control animals at all post-irradiation times up to 67 hours. At 67 hours, a significant net movement of both sodium and water into the lumen was observed. The relationship of these observations to the mechanism of intestinal death has been discussed, The observation that active transport was completely inhibited within 13 hours after irradiation cannot be explained by death of epithelial cells and suggests that there was a direct effect of radiation on the active transport process. (auth)