HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gosling, M Articles by Poyner, D R Search for Related Content PubMed PubMed Citation Articles by Gosling, M Articles by Poyner, D R

Pharmaceutical Sciences Institute, Aston University, Birmingham, UK.

1. During osmotic swelling, cultured osteoblastic cells (ROS 17/2.8) exhibited activation of large amplitude Cl- currents in the whole-cell configuration of the patch-clamp technique. Effects of hypotonic shock on cell volume and membrane conductance were rapidly reversed on return to isotonic conditions. 2. Voltage command pulses in the range -80 to +50 mV produce instantaneous activation of Cl- currents. At potentials more positive than +50 mV the current exhibited time-dependent inactivation. The instantaneous current-voltage relationship was outwardly rectifying. 3. The anion permeability sequence of the induced current was SCN- (2.2) > i- (1.9) > Br- (1.5) > Cl- (1.0) > F- (0.8) > gluconate- (0.2). This corresponds to Eisenman's sequence I. 4. The volume-sensitive Cl- current was effectively inhibited by the Cl- channel blockers 4,4'- diisothiocyanatostilbene-2,2-disulphonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). Outward currents were more effectively suppressed by DIDS than inward currents. The concentrations for 50% inhibition (IC50) of outward and inward currents were 81 and 298 microM, respectively. NPPB was equally effective at inhibiting outward and inward currents (IC50 of 64 microM). The current was relatively insensitive to diphenylamine-2-carboxylate (DPC), 500 microM producing only 22.5 +/- 4.0% inhibition. 5. Inhibitors of protein kinase A (H-89, 1 microM) and tyrosine kinase (tyrphostin A25, 200 microM) were without effect upon activation of Cl- currents in response to hypotonic shock. Under isotonic conditions, elevation of intracellular Ca2+ by ionomycin (1 microM) or activation of protein kinase C by 12-O-tetradecanoylphorbol 13-acetate (TPA, 0.1 microM) failed to evoke increases in basal Cl- conductance levels. 6. It is concluded that an outwardly rectifying Cl- conductance is activated upon osmotic swelling and may be involved in cell volume regulation of ROS 17/2.8 cells.

This article has been cited by other articles:

				D. Soto, N. Comes, E. Ferrer, M. Morales, A. Escalada, J. Pales, C. Solsona, A. Gual, and X. Gasull Modulation of Aqueous Humor Outflow by Ionic Mechanisms Involved in Trabecular Meshwork Cell Volume Regulation Invest. Ophthalmol. Vis. Sci., October 1, 2004; 45(10): 3650 - 3661. [Abstract] [Full Text] [PDF]

				M. Brauer, E. Frei, L. Claes, S. Grissmer, and H. Jager Influence of K-Cl cotransporter activity on activation of volume-sensitive Cl- channels in human osteoblasts Am J Physiol Cell Physiol, July 1, 2003; 285(1): C22 - C30. [Abstract] [Full Text] [PDF]

				J. J. Borg, K. H. Yuill, J. C. Hancox, I. C. Spencer, and R. Z. Kozlowski Inhibitory Effects of the Antiestrogen Agent Clomiphene on Cardiac Sarcolemmal Anionic and Cationic Currents J. Pharmacol. Exp. Ther., October 1, 2002; 303(1): 282 - 292. [Abstract] [Full Text] [PDF]

				Y. M. Shuba, N. Prevarskaya, L. Lemonnier, F. Van Coppenolle, P. G. Kostyuk, B. Mauroy, and R. Skryma Volume-regulated chloride conductance in the LNCaP human prostate cancer cell line Am J Physiol Cell Physiol, October 1, 2000; 279(4): C1144 - C1154. [Abstract] [Full Text] [PDF]

				M. Kolajova and J. M. Baltz Volume-Regulated Anion and Organic Osmolyte Channels in Mouse Zygotes Biol Reprod, April 1, 1999; 60(4): 964 - 972. [Abstract] [Full Text]

				B. D. SCHULTZ, A. K. SINGH, D. C. DEVOR, and R. J. BRIDGES Pharmacology of CFTR Chloride Channel Activity Physiol Rev, January 1, 1999; 79(1): 109 - 144. [Abstract] [Full Text] [PDF]

				K. Liu and S. Luan Voltage-Dependent K+ Channels as Targets of Osmosensing in Guard Cells PLANT CELL, November 1, 1998; 10(11): 1957 - 1970. [Abstract] [Full Text] [PDF]

				V. Crepel, W. Panenka, M. E. M. Kelly, and B. A. MacVicar Mitogen-Activated Protein and Tyrosine Kinases in the Activation of Astrocyte Volume-Activated Chloride Current J. Neurosci., February 15, 1998; 18(4): 1196 - 1206. [Abstract] [Full Text] [PDF]

				L. P. Zanello and A. W. Norman Stimulation by 1alpha ,25(OH)2-Vitamin D3 of Whole Cell Chloride Currents in Osteoblastic ROS 17/2.8 Cells. A STRUCTURE-FUNCTION STUDY J. Biol. Chem., September 5, 1997; 272(36): 22617 - 22622. [Abstract] [Full Text] [PDF]