Chloride channel blockers decrease intracellular pH in cultured renal epithelial LLC-PK1 cells.
The effects of chloride channel blockers upon intracellular pH (pHi) were examined in renal epithelial monolayers of LLC-PK1 cells. A significant intracellular acidification was found with addition of 100 microM 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB), niflumic acid, flufenamate and diphenylamine-2-carboxylate (DPC) but not with 4,4'-diisothiocyanatostilbene-2-2'disulphonic acid (DIDS). The effects of these agents upon pHi was dose-dependent with apparent K0.5 values of: 16.7 +/- 0.3 microM, 34.2 +/- 0.9 microM and 740 +/- 13 microM for niflumic acid, flufenamate and DPC respectively. The results indicate that at concentrations commonly used to block channel activity these chloride channel blockers have profound effects upon pHi.
Brown
C D
CD
Department of Physiological Sciences, Medical School, University of Newcastle upon Tyne.
Dudley
A J
AJ
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000818:Animals; D018118:Chloride Channels / Q000037:antagonists & inhibitors*; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000187:drug effects; D006863:Hydrogen-Ion Concentration / Q000187:drug effects*; D018374:LLC-PK1 Cells; D009544:Niflumic Acid / Q000494:pharmacology; D013552:Swine; D013997:Time Factors
D018118:Chloride Channels; D009544:Niflumic Acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid