Abstract: | Net fluxes of sodium and potassium were studied in Ehrlich mouse ascites tumor cells during contact with the agglutinating protein, concanavalin A. This lectin altered cation transport markedly at concentrations of 20–105 μg/ml (6–47 μg/mg cell protein). Whereas control cells extruded sodium and maintained or accumulated potassium against electrochemical gradients, in the presence of concanavalin A there was rapid net sodium entry and potassium loss. After 10–20 minutes in concanavalin A, sodium extrusion began and potassium loss diminished but these events were prevented by ouabain. The alterations in cation content induced by concanavalin A are unlikely to be the result only of agglutination since soybean agglutinin caused much smaller changes although it agglutinated the cells equally well. |