A basolateral chloride conductance in rat lingual epithelium.
We used Ussing chamber measurements and whole-cell recordings to characterize a chloride conductance in rat lingual epithelium. Niflumic acid (NFA) and flufenamic acid (FFA), nonsteroidal anti-inflammatory aromatic compounds known to inhibit Cl- conductances in other tissues, reduced transepithelial short-circuit current (Isc) in the intact dorsal anterior rat tongue epithelium when added from the serosal side, and reduced whole-cell currents in rat fungiform taste cells. In both Ussing chamber and patch-clamp experiments, the effect of NFA was mimicked by replacement of bath Cl- with methanesulfonate or gluconate. In low Cl- bath solution, the effect of NFA on whole-cell current was reduced. Replacement of bath Ca2+ with Ba2+ reduced the whole-cell Cl- current. We conclude that a Ca2+-activated Cl- conductance is likely present in the basolateral membrane of the rat lingual epithelium, and is present in the taste receptor cells from fungiform papillae. Further experiments will be required to identify the role of this conductance in taste transduction.
Wladkowski
S L
SL
Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, USA.
Lin
W
W
McPheeters
M
M
Kinnamon
S C
SC
Mierson
S
S
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology; D018118:Chloride Channels / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005439:Flufenamic Acid / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009544:Niflumic Acid / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D013650:Taste Buds / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014059:Tongue / Q000166:cytology / Q000378:metabolism*
D018118:Chloride Channels; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D009544:Niflumic Acid; D005439:Flufenamic Acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D002118:Calcium