Takumi Yamashita

Autoradiographic study of tissue distribution of [3H]Ubenimex in IMC carcinoma-bearing mice

[3H]Ubenimex was administered to IMC carcinoma-bearing mice, and the tissue distribution of the radioactivity was examined at various times after drug injection by autoradiography of glutaraldehyde-fixed tissues. Silver grains were concentrated on some of the macrophages present around the solid tumor and in thymic medulla, splenic red pulp, and mesenteric lymph node medulla. The grains were also seen at a similar concentration on some nurse cell-like cells in the thymic cortex and on some reticular cells in splenic red pulp. In the liver, grains were concentrated on the hepatocytes and bile duct epithelium. The grains were most densely concentrated on kidney proximal straight tubules, in which strong leucine aminopeptidase activity was also observed.