A rapid method for the evaluation of the ionic permeabilities across epithelial cell membranes

This short note presents a recipe for the calculation of the ionic permeabi lities across epithelial cell membranes. The method requires the Goldman-Ho dgkin-Katz formalism as well as the consideration of the equivalent electri cal circuit for an epithelial cell. The equivalent electrical circuit is so lved in terms of the equivalent electromotive forces coupled in series with the ionic resistances of both cell membranes (apical and basolateral). The present procedure is feasible for any leaky epithelial cell membrane with the condition that this membrane (apical or basolateral) does not contain p rimary or secondary mechanisms for active transport. (C) 1999 Elsevier Scie nce B,V. All rights reserved.