Cl- transport in basolateral renal medullary vesicles: II. Cl- channels in planar lipid bilayers

W. Brian Reeves, Thomas E. Andreoli

Research output: Contribution to journalArticle

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Abstract

The present studies examined some of the properties of Cl- channels in renal outer medullary membrane vesicles incorporated into planar lipid bilayers. The predominant channel was anion selective having a PCl/PK ratio of 10 and a unit conductance of 93 pS in symmetric 320 mm KCl. In asymmetric KCl solutions, the I-V relations conformed to the Goldman-Hodgkin-Katz equation. Channel activity was voltage-dependent with a gating charge of unity. This voltage dependence of channel activity may account, at least in part, for the striking voltage dependence of the basolateral membrane Cl- conductance of isolated medullary thick ascending limb segments. The Cl- channels incorporated into the planar bilayers were asymmetrical: the trans surface was sensitive to changes in ionized Ca2+ concentrations and insensitive to reducing KCl concentrations to 10 mm, while the cis side was insensitive to changes in ionized Ca2+ concentrations, but was inactivated by reducing KCl concentrations to 50 mm.

Original languageEnglish (US)
Pages (from-to)57-65
Number of pages9
JournalThe Journal of Membrane Biology
Volume113
Issue number1
DOIs
StatePublished - Jan 1 1990

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Keywords

  • Cl channels/bilayers
  • Cl channels/vesicles
  • channel conductance
  • rectification
  • thick ascending limb

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Cell Biology

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