Transepithelial fluctuation analysis of chloride secretion.
Transepithelial fluctuation analysis (noise analysis) provides valuable information about the density and single-channel properties of ion channels in intact epithelia. Here we investigate cystic fibrosis transmembrane conductance regulator (CFTR)-dependent chloride (Cl-) secretion in T84 human colonic epithelia by inducing noise using the diarylsulfonylurea DASU-01, a low-affinity open-channel blocker of CFTR. Our data indicate that the apical membrane of maximally stimulated T84 epithelia has a very high Cl- conductance generated by approximately 7000 active CFTR channels per cell with open probability (Po) of approximately 0.4 and single-channel amplitude (i) of approximately 0.1 pA. Similar experiments might provide important information about how drugs regulate CFTR in intact epithelia.
Singh
Ashvani K
AK
Vertex Pharmaceuticals Inc., 11010 Torreyana Road, San Diego, CA 92121, USA.
Schultz
Bruce D
BD
van Driessche
Willy
W
Bridges
Robert J
RJ
D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D002712:Chlorides / Q000032:analysis / Q000378:metabolism*; D003106:Colon / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008954:Models, Biological; D018408:Patch-Clamp Techniques / Q000379:methods*; D013453:Sulfonylurea Compounds / Q000494:pharmacology
C505032:CFTR protein, human; D018118:Chloride Channels; D002712:Chlorides; D013453:Sulfonylurea Compounds; D019005:Cystic Fibrosis Transmembrane Conductance Regulator