Nitrogen Metabolism Following Whole Body X-Radiation

Abstract

To determine whether the decrease in wt. after irradiation is due to starvation or to an alteration of metabolism, comparison was made of the N balance of rats given whole body X-radiation and of pair-fed non-irradiated controls. During the first 6 post-exposure days the irradiated animals were in much more marked negative N balance than their paired non-irradiated controls. A second, but less marked, period of negative N balance occurred in irradiated rats during the 2d and 3d week. Water intake decreased markedly on the 2d and 3d days after exposure to 660 r, whereas the intake of the control rats increased markedly. Urinary output in both groups followed the same trend as water intake. During the first 3 post-exposure days, rats receiving 660 r showed a greater N excretion and a more negative N balance than rats receiving 1000 r. Possible causes for these changes in N balance are discussed.