ERYTHROCYTES FROM YOSHIDA ASCITES SARCOMA-BEARING RATS HAVE REDUCED SURFACE-CHARGE - THE EFFECT OF TUMOR PRODUCTS

Erythrocytes from the circulation of rats bearing intraperitoneal Yosh ida ascites sarcoma, as well as the red cells contaminating the tumor fluid, exhibit higher concanavalin A (Con Al-mediated agglutination th an the cells from normal animals. Two proteins have been purified eali er from the ascites fluid that can impart high agglutinability on the cells in vitro. We report here that the erythrocytes from the tumor-be aring rats exhibit reduced electrophoretic mobility compared to the ce lls from normal animals (P < 0.001), which correlates with the increas e in their Con A-agglutinability (r = 0.998). The two purified protein s also cause reduction in the electrophoretic mobility of erythrocytes (P < 0.01). Thus the modification of the host cell surface observed i n tumor-bearing rats arises due to non-specific binding of tumor produ cts that reduce the host cell surface charge.