A summary of the fission product metabolism studies up to March 1944

The metabolic properties of the carrier free long lived fission products in the adult rat have been investigated at different intervals ranging from one to sixty-eight days following administration of the radioactive material. The radio elements studied include the most important long lived fission products, namely, Sr, Y, Zr, Cb, Ra, I, Xe, Cs, Ba, La, Ce, Pr, Np, and the unseparated uranium free fission mixture. The routes of administration included intraperitoneal, intramuscular, oral and intrapulmonary. The tissues assayed for the distribution of the administered radio elements included heart, liver, kidney, testes, spleen, muscle, skin, stomach, small intestine, large intestine, bone, blood, lungs, brain, fat, adrenals, lymph nodes. Urine and feces were collected separately at daily intervals for assay. Data acquired is provided in tabular form. For the fission products which were poorly absorbed from the site of both intramuscular arid intraperitoneal injection (namely, Y, Zr, Cb, Ru, La, Ce, Pr, Np, and the uranium free fission mixture) only the intramuscular data are given here and it is expressed in terms of the distribution of the fraction absorbed from the site of injection. For the radio elements which are completely absorbed following intraperitoneal and intramuscular injection or are absorbed in the digestive tract the distribution is expressed in terms of the administered dose. Due to the difficulty of introducing an exactly known dose into the lungs the distribution in this series of experiments is expressed as distribution of retained activity within the animal. A total of 510 animals were used and 10,500 samples assayed with at least two measurements made on each sample. The average measured recovery of the administered dose in the tissue and excreta was 103.6%