Abstract
Outwardly rectified, swelling-activated anion conductances have been described in numerous cell types. The major functional variable observed amongst these conductances is the extent and rate of depolarization-induced inactivation. In general, the conductances can be divided into two broad classes, those that show rapid inactivation in response to strong depolarization and those that show little or no voltage dependence. The swelling-activated anion conductance in rat C6 glioma cells is inactivated nearly completely by membrane depolarization above +90 mV and reactivated by membrane hyperpolarization. The kinetics of inactivation and reactivation are fit by single and double exponentials, respectively. Voltage-dependent behavior is well described by a simple linear kinetic model in which the channel exists in an open or one of three inactivated states. pH- induced changes in voltage-dependent gating suggest that the voltage sensor contains critical basic amino acid residues. Extracellular ATP blocks the channel in a voltage-dependent manner. The block is sensitive to the direction of net Cl- movement and increases open channel noise indicating that ATP interacts with the channel pore. Blockage of the channel with ATP dramatically slows depolarization- induced inactivation.
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Selected References
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- Ackerman M. J., Wickman K. D., Clapham D. E. Hypotonicity activates a native chloride current in Xenopus oocytes. J Gen Physiol. 1994 Feb;103(2):153–179. doi: 10.1085/jgp.103.2.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Armstrong C. M. Interaction of tetraethylammonium ion derivatives with the potassium channels of giant axons. J Gen Physiol. 1971 Oct;58(4):413–437. doi: 10.1085/jgp.58.4.413. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chan H. C., Goldstein J., Nelson D. J. Alternate pathways for chloride conductance activation in normal and cystic fibrosis airway epithelial cells. Am J Physiol. 1992 May;262(5 Pt 1):C1273–C1283. doi: 10.1152/ajpcell.1992.262.5.C1273. [DOI] [PubMed] [Google Scholar]
- Garcia-Perez A., Burg M. B. Renal medullary organic osmolytes. Physiol Rev. 1991 Oct;71(4):1081–1115. doi: 10.1152/physrev.1991.71.4.1081. [DOI] [PubMed] [Google Scholar]
- Jackson P. S., Morrison R., Strange K. The volume-sensitive organic osmolyte-anion channel VSOAC is regulated by nonhydrolytic ATP binding. Am J Physiol. 1994 Nov;267(5 Pt 1):C1203–C1209. doi: 10.1152/ajpcell.1994.267.5.C1203. [DOI] [PubMed] [Google Scholar]
- Jackson P. S., Strange K. Single-channel properties of a volume-sensitive anion conductance. Current activation occurs by abrupt switching of closed channels to an open state. J Gen Physiol. 1995 May;105(5):643–660. doi: 10.1085/jgp.105.5.643. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jackson P. S., Strange K. Volume-sensitive anion channels mediate swelling-activated inositol and taurine efflux. Am J Physiol. 1993 Dec;265(6 Pt 1):C1489–C1500. doi: 10.1152/ajpcell.1993.265.6.C1489. [DOI] [PubMed] [Google Scholar]
- Krafte D. S., Kass R. S. Hydrogen ion modulation of Ca channel current in cardiac ventricular cells. Evidence for multiple mechanisms. J Gen Physiol. 1988 May;91(5):641–657. doi: 10.1085/jgp.91.5.641. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kubo M., Okada Y. Volume-regulatory Cl- channel currents in cultured human epithelial cells. J Physiol. 1992 Oct;456:351–371. doi: 10.1113/jphysiol.1992.sp019340. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewis R. S., Ross P. E., Cahalan M. D. Chloride channels activated by osmotic stress in T lymphocytes. J Gen Physiol. 1993 Jun;101(6):801–826. doi: 10.1085/jgp.101.6.801. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McCann J. D., Li M., Welsh M. J. Identification and regulation of whole-cell chloride currents in airway epithelium. J Gen Physiol. 1989 Dec;94(6):1015–1036. doi: 10.1085/jgp.94.6.1015. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Okada Y., Petersen C. C., Kubo M., Morishima S., Tominaga M. Osmotic swelling activates intermediate-conductance Cl- channels in human intestinal epithelial cells. Jpn J Physiol. 1994;44(4):403–409. doi: 10.2170/jjphysiol.44.403. [DOI] [PubMed] [Google Scholar]
- Paulmichl M., Li Y., Wickman K., Ackerman M., Peralta E., Clapham D. New mammalian chloride channel identified by expression cloning. Nature. 1992 Mar 19;356(6366):238–241. doi: 10.1038/356238a0. [DOI] [PubMed] [Google Scholar]
- Pollard C. E. A volume-sensitive Cl- conductance in a mouse neuroblastoma x rat dorsal root ganglion cell line (F11). Brain Res. 1993 Jun 18;614(1-2):178–184. doi: 10.1016/0006-8993(93)91032-n. [DOI] [PubMed] [Google Scholar]
- Rugolo M., Mastrocola T., De Luca M., Romeo G., Galietta L. J. A volume-sensitive chloride conductance revealed in cultured human keratinocytes by 36Cl- efflux and whole-cell patch clamp recording. Biochim Biophys Acta. 1992 Nov 23;1112(1):39–44. doi: 10.1016/0005-2736(92)90251-g. [DOI] [PubMed] [Google Scholar]
- Solc C. K., Wine J. J. Swelling-induced and depolarization-induced C1-channels in normal and cystic fibrosis epithelial cells. Am J Physiol. 1991 Oct;261(4 Pt 1):C658–C674. doi: 10.1152/ajpcell.1991.261.4.C658. [DOI] [PubMed] [Google Scholar]
- Stevens C. F. Interactions between intrinsic membrane protein and electric field. An approach to studying nerve excitability. Biophys J. 1978 May;22(2):295–306. doi: 10.1016/S0006-3495(78)85490-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoddard J. S., Steinbach J. H., Simchowitz L. Whole cell Cl- currents in human neutrophils induced by cell swelling. Am J Physiol. 1993 Jul;265(1 Pt 1):C156–C165. doi: 10.1152/ajpcell.1993.265.1.C156. [DOI] [PubMed] [Google Scholar]
- Swenson R. P., Jr, Armstrong C. M. K+ channels close more slowly in the presence of external K+ and Rb+. Nature. 1981 Jun 4;291(5814):427–429. doi: 10.1038/291427a0. [DOI] [PubMed] [Google Scholar]
- Tseng G. N. Cell swelling increases membrane conductance of canine cardiac cells: evidence for a volume-sensitive Cl channel. Am J Physiol. 1992 Apr;262(4 Pt 1):C1056–C1068. doi: 10.1152/ajpcell.1992.262.4.C1056. [DOI] [PubMed] [Google Scholar]
- Unwin P. N., Ennis P. D. Two configurations of a channel-forming membrane protein. Nature. 1984 Feb 16;307(5952):609–613. doi: 10.1038/307609a0. [DOI] [PubMed] [Google Scholar]
- Vandenberg C. A., Bezanilla F. A sodium channel gating model based on single channel, macroscopic ionic, and gating currents in the squid giant axon. Biophys J. 1991 Dec;60(6):1511–1533. doi: 10.1016/S0006-3495(91)82186-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weiss D. S., Magleby K. L. Voltage-dependent gating mechanism for single fast chloride channels from rat skeletal muscle. J Physiol. 1992;453:279–306. doi: 10.1113/jphysiol.1992.sp019229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woodhull A. M. Ionic blockage of sodium channels in nerve. J Gen Physiol. 1973 Jun;61(6):687–708. doi: 10.1085/jgp.61.6.687. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Worrell R. T., Butt A. G., Cliff W. H., Frizzell R. A. A volume-sensitive chloride conductance in human colonic cell line T84. Am J Physiol. 1989 Jun;256(6 Pt 1):C1111–C1119. doi: 10.1152/ajpcell.1989.256.6.C1111. [DOI] [PubMed] [Google Scholar]
- Zhang J. F., Siegelbaum S. A. Effects of external protons on single cardiac sodium channels from guinea pig ventricular myocytes. J Gen Physiol. 1991 Dec;98(6):1065–1083. doi: 10.1085/jgp.98.6.1065. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zimmerberg J., Parsegian V. A. Polymer inaccessible volume changes during opening and closing of a voltage-dependent ionic channel. Nature. 1986 Sep 4;323(6083):36–39. doi: 10.1038/323036a0. [DOI] [PubMed] [Google Scholar]
