Virus particles in rat leukemias.

Abstract

Summary Electron microscopic study of 3 transplantable rat leukemias, viz. , lymphocytic (WR-6), acute monocytic (R3149), and chronic myelogenous (LW/12) leukemias, has revealed the presence of C type virus particles. In lymphocytic leukemia, virus particles measuring 85 mµ were frequently observed in the endoplasmic reticulum cisternae of the tumor tissue, spleen, bone marrow, thymus, and lymph nodes, while only a few extracellular virus particles, measuring 100 mµ, were demonstrated in the transplanted tumor tissue and bone marrow of the monocytic and myelogenous leukemias. The etiological relationship of these virus particles to the rat leukemias remains to be established.