The distribution of radioactive iodine in mice with and without tumor 1509la after injection of radioactive sodium iodide.

Abstract

Summary Measurements were made of the distribution of I 131 among the tissues of 206 mice killed either 45 minutes or 25 hours after injection of labeled sodium iodide in quantities varying from 0.0013 to 1.3 μg. of iodine per gram of mouse. Smaller quantities of I 131 were found in the thyroid glands of mice with implants of tumor 15091a than in the thyroids of control mice, although the concentrations of I 131 in their blood were similar. Higher concentrations of I 131 were found in the spleens of tumor mice than in their blood, on some occasions. The explanation for this is uncertain. Splenic enlargement in mice without tumors was not a sufficient cause for such concentration of I 131 . Compared to the concentrations of I 131 in the sera, the livers and ear pinnae of mice contained lower concentrations of I 131 , and their thymus glands contained higher concentrations than did the corresponding tissues in rats. Otherwise, the distribution of the injected iodide was similar in mice and rats.