Activation of the volume-sensitive chloride current in vascular endothelial cells requires a permissive intracellular Ca2+ concentration

G. Szücs, Stephan Heinke, Guy Droogmans, Bernd Nilius

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Combined patch clamp and Ca2+-measurements (Fura-2) were used to study the dependence of volume-activated Cl--currents (ICl,vol) of endothelial cells from bovine pulmonary artery on the intracellular Ca2+-concentration [Ca2+]i. Loading the cells with high concentrations of EGTA or BAPTA via ruptured membrane patches or by preincubating them with 50 μM BAPTA-AM caused a substantial decrease of ICl,vol. This reduction was independent of the activation state of the current: the current amplitude was not only diminished if [Ca2+]i was lowered at the peak of the volume-activated current, but this low Ca2+-concentration also prevented activation of the current by a second hypotonic challenge. ICl,vol is already maximally activated at intracellular Ca2+-concentrations between 50 and 100 nmol/l, a further increase of [Ca2+]i does not affect the size of ICl,vol. These results indicate that a sustained full activation of ICl,vol in endothelial cells requires submicromolar concentrations of Ca2+, and that changes in [Ca2+]i do not modulate the current.

Original languageEnglish
Pages (from-to)467-469
Number of pages3
JournalPflugers Archiv European Journal of Physiology
Volume431
Issue number3
DOIs
Publication statusPublished - Jan 1996

Fingerprint

Endothelial cells
Chlorides
Endothelial Cells
Chemical activation
Egtazic Acid
Pulmonary Artery
Clamping devices
Membranes
fura-2-am
1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester
1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid

Keywords

  • endothelium
  • intracellular Ca
  • patch clamp
  • volume-activated Cl-currents

ASJC Scopus subject areas

  • Physiology

Cite this

Activation of the volume-sensitive chloride current in vascular endothelial cells requires a permissive intracellular Ca2+ concentration. / Szücs, G.; Heinke, Stephan; Droogmans, Guy; Nilius, Bernd.

In: Pflugers Archiv European Journal of Physiology, Vol. 431, No. 3, 01.1996, p. 467-469.

Research output: Contribution to journalArticle

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