Genistein activates CFTR-mediated Cl(-) secretion in the murine trachea and colon.
The action of the isoflavone genistein on the cystic fibrosis transmembrane conductance regulator (CFTR) has been studied in many cell systems but not in intact murine tissues. We have investigated the action of genistein on murine tissues from normal and cystic fibrosis (CF) mice. Genistein increased the short-circuit current (I(sc)) in tracheal (16.4 +/- 2.8 microA/cm(2)) and colonic (40.0 +/- 4.4 microA/cm(2)) epithelia of wild-type mice. This increase was inhibited by furosemide, diphenylamine-2-carboxylate, and glibenclamide, but not by DIDS. In contrast, genistein produced no significant change in the I(sc) of the tracheal epithelium (0.9 +/- 1.1 microA/cm(2)) and decreased the I(sc) of colons from CF null (-13.1 +/- 2.3 microA/cm(2)) and DeltaF508 mice (-10.3 +/- 1.3 microA/cm(2)). Delivery of a human CFTR cDNA-liposome complex to the airways of CF null mice restored the genistein response in the tracheas to wild-type levels. Tracheas from DeltaF508 mice were also studied: 46% of trachea showed no response to genistein, whereas 54% gave an increase in I(sc) similar to that in wild type. We conclude that genistein activates CFTR-mediated Cl(-) secretion in the murine trachea and distal colon.
Department of Physiology, University of Cambridge, United Kingdom. cag24@cam.ac.uk
C A
CA
Goddard
M J
MJ
Evans
W H
WH
Colledge
D000818:Animals; D018118:Chloride Channels / Q000187:drug effects* / Q000502:physiology; D003106:Colon / Q000187:drug effects* / Q000502:physiology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D014132:Trachea / Q000187:drug effects* / Q000502:physiology
C505032:CFTR protein, human; D018118:Chloride Channels; D004791:Enzyme Inhibitors; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D019833:Genistein