Membrane potential measurements in isolated rat liver plasma membrane vesicles: effect of transmembrane ion concentration gradients.

In isolated basolateral and canalicular rat liver plasma membrane vesicles the membrane potential (measured with DiS-C2 (5] varied with transmembrane concentration gradients of Na+, K+ and Cl- revealing the following ion permeabilities: basolateral vesicles: PNa/PK: 0.76, PCl/PK: 0.45 and canalicular vesicles: PNa/PK: 0.69, PCl/PK: 0.56. The data indicate a permselectivity of PK greater than PNa greater than PCl for both membranes.