|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 101, 673-694, Copyright © 1993 by The Rockefeller University Press
ARTICLES |
WH Wang, J Geibel and G Giebisch
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510.
The effects of inhibition of the basolateral Na(+)-K(+)-ATPase (pump) on the apical low-conductance K+ channel of principal cells in rat cortical collecting duct (CCD) were studied with patch-clamp techniques. Inhibition of pump activity by removal of K+ from the bath solution or addition of strophanthidin reversibly reduced K+ channel activity in cell-attached patches to 36% of the control value. The effect of pump inhibition on K+ channel activity was dependent on the presence of extracellular Ca2+, since removal of Ca2+ in the bath solution abolished the inhibitory effect of 0 mM K+ bath. The intracellular [Ca2+] (measured with fura-2) was significantly increased, from 125 nM (control) to 335 nM (0 mM K+ bath) or 408 nM (0.2 mM strophanthidin), during inhibition of pump activity. In contrast, cell pH decreased only moderately, from 7.45 to 7.35. Raising intracellular Ca2+ by addition of 2 microM ionomycin mimicked the effect of pump inhibition on K+ channel activity. 0.1 mM amiloride also significantly reduced the inhibitory effect of the K+ removal. Because the apical low-conductance K channel in inside-out patches is not sensitive to Ca2+ (Wang, W., A. Schwab, and G. Giebisch, 1990. American Journal of Physiology. 259:F494-F502), it is suggested that the inhibitory effect of Ca2+ is mediated by a Ca(2+)-dependent signal transduction pathway. This view was supported in experiments in which application of 200 nM staurosporine, a potent inhibitor of Ca(2+)- dependent protein kinase C (PKC), markedly diminished the effect of the pump inhibition on channel activity. We conclude that a Ca(2+)- dependent protein kinase such as PKC plays a key role in the downregulation of apical low-conductance K+ channel activity during inhibition of the basolateral Na(+)-K(+)-ATPase.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  Y. Zhang, D.-H. Lin, Z.-J. Wang, Y. Jin, B. Yang, and W.-H. Wang K restriction inhibits protein phosphatase 2B (PP2B) and suppression of PP2B decreases ROMK channel activity in the CCD Am J Physiol Cell Physiol, March 1, 2008; 294(3): C765 - C773. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Wei, E. Babilonia, H. Sterling, Y. Jin, and W.-H. Wang Mineralocorticoids decrease the activity of the apical small-conductance K channel in the cortical collecting duct Am J Physiol Renal Physiol, November 1, 2005; 289(5): F1065 - F1071. [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]
|
|
|
|
|
|
H. Sterling, D.-H. Lin, Y. Wei, and W.-H. Wang Tetanus toxin abolishes exocytosis of ROMK1 induced by inhibition of protein tyrosine kinase Am J Physiol Renal Physiol, March 1, 2003; 284(3): F510 - F517. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Lin, H. Sterling, K. M. Lerea, G. Giebisch, and W.-H. Wang Protein Kinase C (PKC)-induced Phosphorylation of ROMK1 Is Essential for the Surface Expression of ROMK1 Channels J. Biol. Chem., November 8, 2002; 277(46): 44278 - 44284. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Lu, S. C. Hebert, and G. Giebisch Hydrolyzable ATP and PIP2 Modulate the Small-conductance K+ Channel in Apical Membranes of Rat Cortical-Collecting Duct (CCD) J. Gen. Physiol., October 29, 2002; 120(5): 603 - 615. [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]
|
|
|
|
|
|
W. Wang Regulation of the ROMK channel: interaction of the ROMK with associate proteins Am J Physiol Renal Physiol, December 1, 1999; 277(6): F826 - F831. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. P. Blaustein and W. J. Lederer Sodium/Calcium Exchange: Its Physiological Implications Physiol Rev, July 1, 1999; 79(3): 763 - 854. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Muto, Y. Asano, D. Seldin, and G. Giebisch Basolateral Na+ pump modulates apical Na+ and K+ conductances in rabbit cortical collecting ducts Am J Physiol Renal Physiol, January 1, 1999; 276(1): F143 - F158. [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]
|
|
|
|
|
|
F. LANG, G. L. BUSCH, M. RITTER, H. VOLKL, S. WALDEGGER, E. GULBINS, and D. HAUSSINGER Functional Significance of Cell Volume Regulatory Mechanisms Physiol Rev, January 1, 1998; 78(1): 247 - 306. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Doi, B. Fakler, J. H. Schultz, U. Schulte, U. Brandle, S. Weidemann, H.-P. Zenner, F. Lang, and J. P. Ruppersberg Extracellular K+ and Intracellular pH Allosterically Regulate Renal Kir1.1 Channels J. Biol. Chem., July 19, 1996; 271(29): 17261 - 17266. [Abstract] [Full Text] [PDF]
|
|
|
|
