A new current expression for selective ion permeation across membranes.

Abstract

Classical Nernst-Planck electrodiffusion approach to selective ion permeation through membranes, remains a currently popular approach to the problem. Some attempts have, however, been made to use Eyring's theory to explain selective ion permeation through the trans-membrane channels. The common problem with either approach is that the final expression for ionic current does not have selectivity inbuilt, rather selectivity is introduced in the current equation as an arbitrarily chosen parameter. In addition, the negative conductance region is non-reproduceable. To the best of our knowledge, we describe, for the first time in the literature, a selective ion current equation which, in addition, also has inbuilt negative conductance property within the framework of a kinematic approach—to a level of first degree approximation.