Abstract
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.
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Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Chao A. C., Mochizuki H. Niflumic and flufenamic acids are potent inhibitors of chloride secretion in mammalian airway. Life Sci. 1992;51(18):1453–1457. doi: 10.1016/0024-3205(92)90540-6. [DOI] [PubMed] [Google Scholar]
- Duszyk M., Liu D., French A. S., Man S. F. Evidence that pH-titratable groups control the activity of a large epithelial chloride channel. Biochem Biophys Res Commun. 1995 Oct 4;215(1):355–360. doi: 10.1006/bbrc.1995.2473. [DOI] [PubMed] [Google Scholar]
- Fanelli A., Berlin W. K., Grollman E. F. Inhibition of iodide transport in rat thyroid cells using N-substituted anthranilic acid derivatives. Thyroid. 1995 Jun;5(3):223–230. doi: 10.1089/thy.1995.5.223. [DOI] [PubMed] [Google Scholar]
- Greger R. Chloride channel blockers. Methods Enzymol. 1990;191:793–810. doi: 10.1016/0076-6879(90)91048-b. [DOI] [PubMed] [Google Scholar]
- Guinamard R., Paulais M., Teulon J. Inhibition of a small-conductance cAMP-dependent Cl- channel in the mouse thick ascending limb at low internal pH. J Physiol. 1996 Feb 1;490(Pt 3):759–765. doi: 10.1113/jphysiol.1996.sp021183. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lukacs G. L., Nanda A., Rotstein O. D., Grinstein S. The chloride channel blocker 5-nitro-2-(3-phenylpropyl-amino) benzoic acid (NPPB) uncouples mitochondria and increases the proton permeability of the plasma membrane in phagocytic cells. FEBS Lett. 1991 Aug 19;288(1-2):17–20. doi: 10.1016/0014-5793(91)80992-c. [DOI] [PubMed] [Google Scholar]
- Park K., Brown P. D. Intracellular pH modulates the activity of chloride channels in isolated lacrimal gland acinar cells. Am J Physiol. 1995 Mar;268(3 Pt 1):C647–C650. doi: 10.1152/ajpcell.1995.268.3.C647. [DOI] [PubMed] [Google Scholar]
- Thwaites D. T., Brown C. D., Hirst B. H., Simmons N. L. Transepithelial glycylsarcosine transport in intestinal Caco-2 cells mediated by expression of H(+)-coupled carriers at both apical and basal membranes. J Biol Chem. 1993 Apr 15;268(11):7640–7642. [PubMed] [Google Scholar]