AUTORADIOGRAPHIC LOCALIZATION OF TRITIATED SURAMIN POLARIZED HUMAN COLON ADENOCARCINOMA CELLS

In this report we demonstrated that [H-3]suramin enters polarized huma n colon adenocarcinoma cells when added to the apical side of the mono layer. Using light microscopic quantitative autoradiography, we showed that suramin was accumulated in the apical eytoplasm and in the nucle us. In contrast, a weak labeling was noted in other compartments such as the basolateral cytoplasm and the intercellular space. The accumula tion of suramin in the apical region of the cells is consistent with p revious data showing that suramin elicited a lysosomal storage disorde r in HT29-D4 cells by a mechanism of polarized endocytosis.