|
|
||||||||
AJP - Cell Physiology, Vol 273, Issue 2 C531-C540, Copyright © 1997 by American Physiological Society
ARTICLES |
D. C. Devor, A. K. Singh, A. C. Gerlach, R. A. Frizzell and R. J. Bridges
Department of Cell Biology and Physiology, University of Pittsburgh, Pennsylvania 15261, USA. dd2+@pitt.edu
We evaluated the effects of clotrimazole and clofibrate on Ca(2+)- and adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion in the colonic cell line, T84. We used 1-ethyl-2-benzimidazolinone (1-EBIO) to activate the Ca(2+)-dependent K+ channel (KCa) in these cells to induce a sustained Cl- secretory current (Isc). Clotrimazole potently inhibited the KCa-dependent Isc, with an inhibition constant (Ki) of 0.27 +/- 0.02 microM. Clofibrate also inhibited the 1-EBIO-induced Isc albeit with lower affinity (Ki = 6.5 +/- 1.2 microM). Clotrimazole (10 microM) inhibited the Isc response to the Ca(2+)-mediated agonist, carbachol, by 82%. Similarly, both clotrimazole and clofibrate inhibited cAMP-mediated Cl- secretion, with Ki values of 5.2 +/- 1.0 and 6.7 +/- 1.1 microM, respectively. We used nystatin to permeabilize the apical or basolateral membrane to determine the effects of clotrimazole and clofibrate on the basolateral K+ (IK) and apical Cl- (ICl) currents following stimulation by either 1-EBIO or forskolin. Both clotrimazole and clofibrate inhibited the 1-EBIO- and forskolin-induced IK without affecting ICl. We determined the effects of clotrimazole and clofibrate on KCa using 86Rb+ uptake studies into membrane vesicles. Both clotrimazole and clofibrate inhibited the 1-EBIO-induced 86Rb+ uptake, with Ki values of 0.31 +/- 0.08 and 10.8 +/- 5.5 microM, respectively. Similarly, clotrimazole inhibited the Ca(2+)-induced 86Rb+ uptake with a Ki of 0.51 +/- 0.15 microM. Charybdotoxin inhibited both the 1-EBIO- and Ca(2+)-induced 86Rb+ uptakes with similar affinities (Ki values of 0.57 +/- 0.07 and 0.47 +/- 0.08 nM, respectively), suggesting 1-EBIO and Ca2+ activate the same channel (KCa) in this assay. In excised, single-channel recordings both clotrimazole and clofibrate inhibited KCa, demonstrating a direct inhibition of the channel by these compounds. We demonstrate that clotrimazole blocks the intestinal KCa, thereby inhibiting Cl- secretion. These results suggest that clotrimazole may be useful as an antidiarrheal.
This article has been cited by other articles:
![]() |
D. Heitzmann and R. Warth Physiology and Pathophysiology of Potassium Channels in Gastrointestinal Epithelia Physiol Rev, July 1, 2008; 88(3): 1119 - 1182. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. Bajwa, A. Alioua, J. W. Lee, D. S. Straus, L. Toro, and C. Lytle Fenofibrate inhibits intestinal Cl secretion by blocking basolateral KCNQ1 K+ channels Am J Physiol Gastrointest Liver Physiol, December 1, 2007; 293(6): G1288 - G1299. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Dong, A. Smith, M. Hovaida, and J. Y. Chow Role of Ca2+-activated K+ channels in duodenal mucosal ion transport and bicarbonate secretion Am J Physiol Gastrointest Liver Physiol, December 1, 2006; 291(6): G1120 - G1128. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. T. Halm, T. Liao, and D. R. Halm Distinct K+ conductive pathways are required for Cl- and K+ secretion across distal colonic epithelium Am J Physiol Cell Physiol, October 1, 2006; 291(4): C636 - C648. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. L. Hamilton and M. Kiessling DCEBIO stimulates Cl- secretion in the mouse jejunum Am J Physiol Cell Physiol, January 1, 2006; 290(1): C152 - C164. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Baker and K. L. Hamilton Genistein stimulates electrogenic Cl- secretion in mouse jejunum Am J Physiol Cell Physiol, December 1, 2004; 287(6): C1636 - C1645. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Ouadid-Ahidouch, M. Roudbaraki, P. Delcourt, A. Ahidouch, N. Joury, and N. Prevarskaya Functional and molecular identification of intermediate-conductance Ca2+-activated K+ channels in breast cancer cells: association with cell cycle progression Am J Physiol Cell Physiol, July 1, 2004; 287(1): C125 - C134. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. J. Joiner, S. Basavappa, S. Vidyasagar, K. Nehrke, S. Krishnan, H. J. Binder, E. L. Boulpaep, and V. M. Rajendran Active K+ secretion through multiple KCa-type channels and regulation by IKCa channels in rat proximal colon Am J Physiol Gastrointest Liver Physiol, June 9, 2003; 285(1): G185 - G196. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. O'Grady and S. Y. Lee Chloride and potassium channel function in alveolar epithelial cells Am J Physiol Lung Cell Mol Physiol, May 1, 2003; 284(5): L689 - L700. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. R. Hallows, G. P. Kobinger, J. M. Wilson, L. A. Witters, and J. K. Foskett Physiological modulation of CFTR activity by AMP-activated protein kinase in polarized T84 cells Am J Physiol Cell Physiol, May 1, 2003; 284(5): C1297 - C1308. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Roman P-450 Metabolites of Arachidonic Acid in the Control of Cardiovascular Function Physiol Rev, January 1, 2002; 82(1): 131 - 185. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kunzelmann and M. Mall Electrolyte Transport in the Mammalian Colon: Mechanisms and Implications for Disease Physiol Rev, January 1, 2002; 82(1): 245 - 289. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Gao, J. R. Yankaskas, C. M. Fuller, E. J. Sorscher, S. Matalon, H. J. Forman, and C. J. Venglarik Chlorzoxazone or 1-EBIO increases Na+ absorption across cystic fibrosis airway epithelial cells Am J Physiol Lung Cell Mol Physiol, November 1, 2001; 281(5): L1123 - L1129. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. L. Sedlacek, R. W. Carlin, A. K. Singh, and B. D. Schultz Neurotransmitter-stimulated ion transport by cultured porcine vas deferens epithelium Am J Physiol Renal Physiol, September 1, 2001; 281(3): F557 - F570. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. U. Cotton Basolateral Potassium Channels and Epithelial Ion Transport Am. J. Respir. Cell Mol. Biol., September 1, 2000; 23(3): 270 - 272. [Full Text] |
||||
![]() |
M. Mall, A. Wissner, R. Schreiber, J. Kuehr, H. H. Seydewitz, M. Brandis, R. Greger, and K. Kunzelmann Role of KVLQT1 in Cyclic Adenosine Monophosphate-Mediated Cl- Secretion in Human Airway Epithelia Am. J. Respir. Cell Mol. Biol., September 1, 2000; 23(3): 283 - 289. [Abstract] [Full Text] |
||||
![]() |
M. Trucksis, T. L. Conn, S. S. Wasserman, and C. L. Sears Vibrio cholerae ACE stimulates Ca2+-dependent Cl-/HCO3- secretion in T84 cells in vitro Am J Physiol Cell Physiol, September 1, 2000; 279(3): C567 - C577. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Syme, A. C. Gerlach, A. K. Singh, and D. C. Devor Pharmacological activation of cloned intermediate- and small-conductance Ca2+-activated K+ channels Am J Physiol Cell Physiol, March 1, 2000; 278(3): C570 - C581. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. K. Singh, D. C. Devor, A. C. Gerlach, M. Gondor, J. M. Pilewski, and R. J. Bridges Stimulation of Cl- Secretion by Chlorzoxazone J. Pharmacol. Exp. Ther., February 1, 2000; 292(2): 778 - 787. [Abstract] [Full Text] |
||||
![]() |
A. C. Gerlach, N. N. Gangopadhyay, and D. C. Devor Kinase-dependent Regulation of the Intermediate Conductance, Calcium-dependent Potassium Channel, hIK1 J. Biol. Chem., January 7, 2000; 275(1): 585 - 598. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. B. Campbell and D. R. Harder Endothelium-Derived Hyperpolarizing Factors and Vascular Cytochrome P450 Metabolites of Arachidonic Acid in the Regulation of Tone Circ. Res., March 5, 1999; 84(4): 484 - 488. [Full Text] [PDF] |
||||
![]() |
D. H. Vandorpe, B. E. Shmukler, L. Jiang, B. Lim, J. Maylie, J. P. Adelman, L. de Franceschi, M. D. Cappellini, C. Brugnara, and S. L. Alper cDNA Cloning and Functional Characterization of the Mouse Ca2+-gated K+ Channel, mIK1. ROLES IN REGULATORY VOLUME DECREASE AND ERYTHROID DIFFERENTIATION J. Biol. Chem., August 21, 1998; 273(34): 21542 - 21553. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Merlin, L. Jiang, G. R. Strohmeier, A. Nusrat, S. L. Alper, W. I. Lencer, and J. L. Madara Distinct Ca2+- and cAMP-dependent anion conductances in the apical membrane of polarized T84 cells Am J Physiol Cell Physiol, August 1, 1998; 275(2): C484 - C495. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. C. Devor and R. A. Frizzell Modulation of K+ channels by arachidonic acid in T84 cells. I. Inhibition of the Ca2+-dependent K+ channel Am J Physiol Cell Physiol, January 1, 1998; 274(1): C138 - C148. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |