Modulation of thymocyte membrane potential by concanavalin A.

Binding of convanavalin A, a potent mitogenic lectin, to thymocyte surface membrane causes depolarization of membrane potential. The effect is suppressed by alpha-methyl-D-glucoside, a haptenic inhibitor of this lectin, or by low temperature. Colchicine and cytochalasin B aslso suppress the change. These data indicate that perturbation of thymocyte surface membrane receptors induced by concanavalin A might be linked to change in the functional state of cellular cytoskeletal systems in turn causing depolarization of thymocyte surface membrane. The initial event generated by receptor-ligand interaction on the outer surface could be translated into cellular interior action only under highly fluid conditions of membrane lipid. Depolarization of thymocyte plasma membrane may be involved in the triggering mechanism of metabolic burst associated with blastoid transformation.