Role of Na§ § Exchange in the Control of Intracellular pH and Cell Membrane Conductances in Frog Skin Epithelium

I N T R O D U C T I O N Changes in ion permeability at one epithelial cell membrane are often associated with modifications in ion t ransport at the opposing membrane ("cross-talk") (Schultz, 1981; Diamond, 1982). The nature of the cellular signal for "cross-talk" is not known, however, in a companion paper (Harvey et al., 1988) we have shown that sodium and potassium conductances in frog skin epithelium are very sensitive to slight variations in intracellular p H (pHi. This raises the interesting possibility that the mechanism(s) regulating p H i could also influence transepithelial ion transport. An understanding of how this epithelium maintains and regulates cell H § is, therefore, essential in interpreting changes in pHi and their electrical effects. BasoAddress reprint requests to Dr. Brian J. Harvey, Laboratoire Jean Maetz, B.P. 68, Station Marine, 06230 Villefranche-sur-Mer, France. J. GEN. Pm'sloL. 9 The Rockefeller University Press 9 0022-1295/88/12/0793/18 $2.00 793 Volume 92 December 1988 793-810 on O cber 9, 2016 D ow nladed fom Published December 1, 1988