349 - Membrane potential and ion permeability of lipid bilayer membranes

In order to clarify the components consisting of transmembrane potential of membranes, measurements of surface potentials of phospholipid monolayers and concentration potentials of phospholipid bilayer membranes measurements were carried out with respect to salt concentrations.It was concluded that, for a highly charged membranes symmetrical with respect to the surface charge density, the observed transmembrane potential is due mostly to the difference between the two surface potentials on both sides of the membrane. On the other hand, for an uncharged membrane, the transmembrane potential is due to the ion diffusion potential through the membrane.Some discussion concerning ion permeabilities through the membranes is also made in relation to the observed transmembrane potentials.