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PMID: 2422661 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

Amiloride-sensitive Na channels from the apical membrane of the rat cortical collecting tubule.

Proceedings of the National Academy of Sciences of the United States of America ·Vol. 83 ·No. 8 ·1986-04-00 ·Pages 2767-70

Palmer LG, Frindt G

Abstract

Currents through individual Na channels in the apical membrane of the rat cortical collecting tubule were resolved by using the patch-clamp technique. In cell-attached patches, the channels had a conductance of 5 pS with 140 mM NaCl in the pipet. The conductance was a saturable function of external Na, with a maximal value of about 8 pS and a half saturation at about 75 mM Na. In excised inside-out patches, the selectivity of the channels for Na over K was estimated from reversal potentials to be at least 10:1. The channels underwent spontaneous transitions between open and closed states. Both states had mean lifetimes of 3-4 sec. Amiloride (0.5 microM) added to the pipet induced more frequent closures and openings of the channels and a reduction in the mean open time. These channels are presumed to mediate Na reabsorption by this nephron segment in vivo.

MeSH Terms
Amiloride/pharmacology Animals Electric Conductivity Female Ion Channels/drug effects,physiology Kidney Tubules/physiology Kidney Tubules, Collecting/physiology Male Membrane Potentials Rats Sodium/physiology
Chemicals
Ion Channels Amiloride Sodium
Authors & Affiliations
2 authors, click to expand affiliations / ORCID
Palmer L G
Frindt G
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20 references, click to expand
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Article Info
Journal
Proceedings of the National Academy of Sciences of the United States of America
Abbr.
Proc Natl Acad Sci U S A
ISSN
0027-8424
DOI
10.1073/pnas.83.8.2767
Published
1986-04-00
Pages
2767-70
Language
English
Region
United States
NLM ID
7505876
PMCID
PMC323382
Subset
IM
Grants
NIADDK NIH HHS · AM11489 · United States
NIADDK NIH HHS · AM27847 · United States
External Links
PubMed source DOI: 10.1073/pnas.83.8.2767 PMC Full Text View journal details
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