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.
Vertex Pharmaceuticals Inc., 11010 Torreyana Road, San Diego, CA 92121, USA.
Ashvani K
AK
Singh
Bruce D
BD
Schultz
Willy
W
van Driessche
Robert J
RJ
Bridges
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