
Fig. 7. (A) Establishment of a reversed (negative sign) current (abbreviated as IKrev in the text) after apical (a) permeabilisation with nystatin and its inhibition by apical or basolateral (b) acidification. K32, standard saline (see Materials and methods); Na32, all K+ in the saline replaced by Na+. (B) Percentage of control pump current (IP, left side, N=4) and reversed current (IKrev, right side, N=4) following intracellular acidification via basolateral (left side) or apical (right side) nystatin channels. Values are means + S.E.M.