AJP - Renal Physiology, Vol 266, Issue 5 813-F822, Copyright © 1994 by American Physiological Society

ARTICLES

A novel approach allows identification of K channels in the lateral membrane of rat CCD

W. H. Wang, C. M. McNicholas, A. S. Segal and G. Giebisch
Department of Pharmacology, New York Medical College, Valhalla 10595.

We have developed a novel approach to study K channels in the lateral membrane of principal cells (PC) in rat cortical collecting ducts (CCD). The technique consists of 1) exposing the CCD apical membrane, 2) removing the intercalated cells adjoining a PC by gentle suction through a pipette, and 3) applying patch-clamp technique to the lateral membrane of PC. Functional viability of the PC was confirmed by three indexes: 1) maintenance of physiological cell membrane potentials (-85 +/- 3 mV); 2) depolarization of the cell membrane potential with 1 mM Ba2+; and 3) hyperpolarization of the cell potential with 0.1 mM amiloride. Two types of K channels were identified: a low-conductance K channel and an intermediate-conductance K channel. In cell-attached patches the slope conductance of the low-conductance K channel was 27 pS and that of the intermediate-conductance K channel was 45 pS. The open probability (Po) of the 27-pS K channel was 0.81 +/- 0.02 and was not voltage dependent. In contrast, the Po of the 45-pS K channel was 0.23 +/- 0.01 at the spontaneous cell membrane potential and was increased by hyperpolarization. In addition, decrease of the bath pH from 7.4 to 6.7 reduced the 27-pS K channel current amplitude in a voltage-dependent manner, but the Po was not affected. Finally, two time constants were required to fit open- and closed-time histograms of both populations of K channels. Application of 1 mM Ba2+ completely blocked these K channels. We conclude that two types of K channel are present in the basolateral membrane of PC.

This article has been cited by other articles:

				S. Lachheb, F. Cluzeaud, M. Bens, M. Genete, H. Hibino, S. Lourdel, Y. Kurachi, A. Vandewalle, J. Teulon, and M. Paulais Kir4.1/Kir5.1 channel forms the major K+ channel in the basolateral membrane of mouse renal collecting duct principal cells Am J Physiol Renal Physiol, June 1, 2008; 294(6): F1398 - F1407. [Abstract] [Full Text] [PDF]

				Z. Wang, Y. Wei, J. R. Falck, K. R. Atcha, and W.-H. Wang Arachidonic acid inhibits basolateral K channels in the cortical collecting duct via cytochrome P-450 epoxygenase-dependent metabolic pathways Am J Physiol Renal Physiol, June 1, 2008; 294(6): F1441 - F1447. [Abstract] [Full Text] [PDF]

				C. Alewine, B.-y. Kim, V. Hegde, and P. A. Welling Lin-7 targets the Kir 2.3 channel on the basolateral membrane via a L27 domain interaction with CASK Am J Physiol Cell Physiol, December 1, 2007; 293(6): C1733 - C1741. [Abstract] [Full Text] [PDF]

				A. Nissant, M. Paulais, S. Lachheb, S. Lourdel, and J. Teulon Similar chloride channels in the connecting tubule and cortical collecting duct of the mouse kidney Am J Physiol Renal Physiol, June 1, 2006; 290(6): F1421 - F1429. [Abstract] [Full Text] [PDF]

				D. A. Gray, G. Frindt, Y.-Y. Zhang, and L. G. Palmer Basolateral K+ conductance in principal cells of rat CCD Am J Physiol Renal Physiol, March 1, 2005; 288(3): F493 - F504. [Abstract] [Full Text] [PDF]

				S. C. Hebert, G. Desir, G. Giebisch, and W. Wang Molecular Diversity and Regulation of Renal Potassium Channels Physiol Rev, January 1, 2005; 85(1): 319 - 371. [Abstract] [Full Text] [PDF]

				S. Muto, Y. Asano, W. Wang, D. Seldin, and G. Giebisch Activity of the basolateral K+ channels is coupled to the Na+-K+-ATPase in the cortical collecting duct Am J Physiol Renal Physiol, November 1, 2003; 285(5): F945 - F954. [Abstract] [Full Text] [PDF]

				Y. Wei and W. Wang Angiotensin II stimulates basolateral K channels in rat cortical collecting ducts Am J Physiol Renal Physiol, January 1, 2003; 284(1): F175 - F181. [Abstract] [Full Text] [PDF]

				J. A. Schafer Abnormal regulation of ENaC: syndromes of salt retention and salt wasting by the collecting duct Am J Physiol Renal Physiol, August 1, 2002; 283(2): F221 - F235. [Abstract] [Full Text] [PDF]

				Y. Wei, M. Lu, and W. Wang Ca2+ mediates the effect of inhibition of Na+-K+-ATPase on the basolateral K+ channels in the rat CCD Am J Physiol Cell Physiol, April 1, 2001; 280(4): C920 - C928. [Abstract] [Full Text] [PDF]

				S. Muto Potassium Transport in the Mammalian Collecting Duct Physiol Rev, January 1, 2001; 81(1): 85 - 116. [Abstract] [Full Text] [PDF]

				X. Zhou, I. J. Lynch, S.-L. Xia, and C. S. Wingo Activation of H+-K+-ATPase by CO2 requires a basolateral Ba2+-sensitive pathway during K restriction Am J Physiol Renal Physiol, July 1, 2000; 279(1): F153 - F160. [Abstract] [Full Text] [PDF]

				W. H. Wang The cGMP-dependent protein kinase stimulates the basolateral 18-pS K channel of the rat CCD Am J Physiol Cell Physiol, June 1, 2000; 278(6): C1212 - C1217. [Abstract] [Full Text] [PDF]

				C. Walther, K. E. Zittlau, H. Murck, and K. Voigt Resting Membrane Properties of Locust Muscle and Their Modulation I. Actions of the Neuropeptides YGGFMRFamide and Proctolin J Neurophysiol, August 1, 1998; 80(2): 771 - 784. [Abstract] [Full Text] [PDF]

				M. Lu and W.-H. Wang Reaction of nitric oxide with superoxide inhibits basolateral K+ channels in the rat CCD Am J Physiol Cell Physiol, July 1, 1998; 275(1): C309 - C316. [Abstract] [Full Text] [PDF]

				G. Giebisch Renal potassium transport: mechanisms and regulation Am J Physiol Renal Physiol, May 1, 1998; 274(5): F817 - F833. [Abstract] [Full Text] [PDF]

				S. Le Maout, M. Brejon, O. Olsen, J. Merot, and P. A. Welling Basolateral membrane targeting of a renal-epithelial inwardly rectifying potassium channel from the cortical collecting duct, CCD-IRK3, in MDCK cells PNAS, November 25, 1997; 94(24): 13329 - 13334. [Abstract] [Full Text] [PDF]

				P. A. Welling Primary structure and functional expression of a cortical collecting duct Kir channel Am J Physiol Renal Physiol, November 1, 1997; 273(5): F825 - F836. [Abstract] [Full Text] [PDF]

				M. Paulais, S. Lourdel, and J. Teulon Properties of an inwardly rectifying K+ channel in the basolateral membrane of mouse TAL Am J Physiol Renal Physiol, May 1, 2002; 282(5): F866 - F876. [Abstract] [Full Text] [PDF]