Effect of whole-body x radiation on plasma iron disappearance in the rat

¹ Physics Department, The University of Texas M. D. Anderson Hospital and Tumor Institute, Texas Medical Center, Houston, Texas

Studies on the plasma disappearance half-time of Fe⁵⁹ in whole-body and liver- and spleen-shielded rats given 50–800 rad of 200-kvp X rays showed that the half-time became successively longer with doses up to 600 rad (at a level 2.7 times control value). After 600 rad, plasma disappearance half-time began to fall again, but at this level substantial changes also occurred in plasma iron concentration. The time to reach the maximum increase in plasma disappearance half-time continued to rise and was linear with dose up to 700 rad. The changes in plasma iron disappearance half-time have been shown to be directly related to iron uptake changes but the time for the maximum effect in plasma disappearance precedes that for uptake consistently by 0.5 days. Therefore, plasma iron disappearance half-time is a useful practical parameter of radiation injury in the rat up to about the ld₅₀.