Studies on the Anemia of Tumor-Bearing Animals. III. Localization of Erythrocyte Iron Within the Tumor

Abstract

When erythrocytes tagged with Cr⁵¹ were mixed with erythrocytes labeled with Fe⁵⁹, both isotopes were distributed in the same pattern in Lymphosarcoma R2788 of the rat. Most of the radioisotope was deposited in hemorrhagic areas, almost none in firm, viable tumor, and an intermediate amount in the necrotic areas. Most of the iron found within the tumor was shown to have been derived from the erythrocytes. Microscopic examination of stained and incinerated sections of Lymphosarcoma R2788 showed a major portion of the iron to be present as deposits of hemosiderin in macrophages surrounding the hemorrhagic areas, with little being detectable within the tumor cells. Other tumors had widely varying patterns of vascular injury. The relationship of the anemia in the host to the vascular lesions in the tumor is discussed.