AJP - Renal Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 253: F476-F487, 1987;
0363-6127/87 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sackin, H.
Right arrow Articles by Palmer, L. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sackin, H.
Right arrow Articles by Palmer, L. G.

AJP - Renal Physiology, Vol 253, Issue 3 476-F487, Copyright © 1987 by American Physiological Society

ARTICLES

Basolateral potassium channels in renal proximal tubule

H. Sackin and L. G. Palmer

Potassium (K+) channels in the basolateral membrane of unperfused Necturus proximal tubules were studied in both cell-attached and excised patches, after removal of the tubule basement membrane by manual dissection without collagenase. Two different K+ channels were identified on the basis of their kinetics: a short open-time K+ channel, with a mean open time less than 1 ms, and a long open-time K+ channel with a mean open time greater than 20 ms. The short open-time channel occurred more frequently than the longer channel, especially in excised patches. For inside-out excised patches with Cl- replaced by gluconate, the current-voltage relation of the short open-time K+ channel was linear over +/- 60 mV, with a K+-Na+ selectivity of 12 +/- 2 (n = 12), as calculated from the reversal potential with oppositely directed Na+ and K+ gradients. With K-Ringer in the patch pipette and Na-Ringer in the bath, the conductance of the short open-time channel was 47 +/- 2 pS (n = 15) for cell-attached patches, 26 +/- 2 pS (n = 15) for patches excised (inside out) into Na-Ringer, and 36 +/- 6 pS (n = 3) for excised patches with K-Ringer on both sides. These different conductances can be partially explained by a dependence of single-channel conductance on the K+ concentration on the interior side of the membrane. In experiments with a constant K+ gradient across excised patches, large changes in Na+ at the interior side of the membrane produced no change in single-channel conductance, arguing against a direct block of the K+ channel by Na+. Finally, the activity of the short open-time channel was voltage gated, where the mean number of open channels decreased as a linear function of basolateral membrane depolarization for potentials between -60 and 0 mV. Depolarization from -60 to -40 mV decreased the mean number of open K+ channels by 28 +/- 8% (n = 6).


This article has been cited by other articles:


Home page
 Physiol. Rev.Home page
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]

Home page
 Am. J. Physiol. Renal Physiol.Home page
C. G. Hurwitz, V. Y. Hu, and A. S. Segal
A mechanogated nonselective cation channel in proximal tubule that is ATP sensitive
Am J Physiol Renal Physiol, July 1, 2002; 283(1): F93 - F104.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
C. Duranton, E. Mikulovic, M. Tauc, M. Avella, and P. Poujeol
Potassium channels in primary cultures of seawater fish gill cells. I. Stretch-activated K+ channels
Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2000; 279(5): R1647 - R1658.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online