1. The distribution of Fe59 in plasma, bone marrow, erythrocytes, liver, and spleen was determined at specified intervals after single intravenous injections of the radioisotope into normal and protein-deficient rats.
2. In normal rats, injected radioiron followed the usual metabolic pathways; i.e., through bone marrow to erythrocytes, with small, consistent amounts to liver and spleen.
3. In protein-deficient animals normal Fe59 time-concentration relationships were disrupted completely.
4. Less iron was recovered from the tissues of protein-deficient rats than from normal animals.
5. Storage iron in liver and spleen was not conjugated with polysaccharide, even though tissue protein was seriously depleted.