|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 92, 643-665, Copyright © 1988 by The Rockefeller University Press
ARTICLES |
JD Horisberger and G Giebisch
Yale University School of Medicine, Department of Physiology, New Haven, Connecticut 06510-8026.
Membrane potentials and conductances, and intracellular ionic activities were studied in isolated perfused collecting tubules of K+- adapted Amphiuma. Intracellular Na+ (aNai) and K+ (aKi) activities were measured, using liquid ion-exchanger double-barreled microelectrodes. Apical and basolateral membrane conductances were estimated by cable analysis. The effects of inhibition of the apical conductance by amiloride (10(-5) M) and of inhibition of the basolateral Na-K pump by either a low K+ (0.1 mM) bath or by ouabain (10(-4) M) were studied. Under control conditions, aNai was 8.4 +/- 1.9 mM and aKi 56 +/- 3 mM. With luminal amiloride, aNai decreased to 2.2 +/- 0.4 mM and aKi increased to 66 +/- 3 mM. Ouabain produced an increase of aNai to 44 +/- 4 mM, and a decrease of aKi to 22 +/- 6, and similar changes were observed when the tubule was exposed to a low K+ bath solution. During pump inhibition, there was a progressive decrease of the K+-selective basolateral membrane conductance and of the Na+ permeability of the apical membrane. A similar inhibition of both membrane conductances was observed after pump inhibition by low K+ solution. Upon reintroduction of K+, a basolateral membrane hyperpolarization of -23 +/- 4 mV was observed, indicating an immediate reactivation of the electrogenic Na-K pump. However, the recovery of the membrane conductances occurred over a slower time course. These data imply that both membrane conductances are regulated according to the intracellular ionic composition, but that the basolateral K+ conductance is not directly linked to the pump activity.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  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]
|
|
|
|
 |
|
 U. I. M. Wiehart, G. Klein, P. Steels, S. W. Nicolson, and E. Van Kerkhove K+ transport in Malpighian tubules of Tenebrio molitor L.: is a KATP channel involved? J. Exp. Biol., March 15, 2003; 206(6): 959 - 965. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Crambert, J.-D. Horisberger, N. N. Modyanov, and K. Geering Human nongastric H+-K+-ATPase: transport properties of ATP1al1 assembled with different beta -subunits Am J Physiol Cell Physiol, July 1, 2002; 283(1): C305 - C314. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Heinzinger, F. van den Boom, H. Tinel, and F. Wehner In rat hepatocytes, the hypertonic activation of Na+ conductance and Na+-K+-2Cl- symport - but not Na+-H+ antiport - is mediated by protein kinase C J. Physiol., November 1, 2001; 536(3): 703 - 715. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Burnay, G. Crambert, S. Kharoubi-Hess, K. Geering, and J.-D. Horisberger Bufo marinus bladder H-K-ATPase carries out electroneutral ion transport Am J Physiol Renal Physiol, November 1, 2001; 281(5): F869 - F874. [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]
|
|
|
|
|
|
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]
|
|
|
|
|
|
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]
|
|
|
|
|
|
F. Wehner and H. Tinel Role of Na+ conductance, Na+-H+ exchange, and Na+-K+-2Cl- symport in the regulatory volume increase of rat hepatocytes J. Physiol., January 1, 1998; 506(1): 127 - 142. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Lu, G. Giebisch, and W. Wang Nitric Oxide Links the Apical Na+ Transport to the Basolateral K+ Conductance in the Rat Cortical Collecting Duct J. Gen. Physiol., December 1, 1997; 110(6): 717 - 726. [Abstract] [Full Text] [PDF]
|
|
|
|
