Multiple types of chloride channels in bovine pulmonary artery endothelial cells

Bernd Nilius, G. Szücs, Stefan Heinke, Thomas Voets, Guy Droogmans

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

We have characterized two different types of Cl- currents in calf pulmonary artery endothelial (CPAE) cells by using a combined patch-clamp and Fura-2 microfluorescence technique to measure simultaneously ionic currents and the intracellular Ca2+ concentration, [Ca2+](i). Exposure of CPAE cells to 28% hypotonic solution induces cell swelling without a change in membrane capacitance and [Ca2+](i), and concomitantly activates a current. This current, I(Cl,vol), is closely correlated with the changes in cell volume and shows a modest outward rectification. It slowly inactivates at potentials more positive than +60 mV but is time- and voltage-independent at other potentials. Increase in [Ca2+](i) by different maneuvers, such as application of vasoactive agonists (ATP), ionomycin, or loading of the cells directly with Ca2+ also activates a Cl- current, I(Cl,Ca). This current slowly activates at positive potentials, inactivates quickly at negative potentials and shows strong outward rectification. A time-independent component of the current activated by elevation of [Ca2+](i) alone can be inhibited by cell shrinking by exposing the cells to hypertonic solution, indicating that an increase in [Ca2+](i) also co-activates I(Cl,vol). Forskolin or cAMP never activated a current in CPAE cells, which indicates the lack of cAMP-activated channels in these cells. There is also no evidence for the existence of voltage-gated Cl- channels in resting, nonstimulated cells. Challenging a cell with elevated [Ca2+](i) and hypotonic solutions activated I(Cl,vol) on top of I(Cl,Ca), suggesting that I(Cl,Ca) and I(Cl,vol) are different channels. We conclude that CPAE cells do not express voltage-gated (ClC-type) or cAMP-gated (CFTR-type) Cl- channels, but activate large Cl- currents after volume (mechanical?) or chemical (Ca2+) stimulation.

Original languageEnglish
Pages (from-to)220-228
Number of pages9
JournalJournal of Vascular Research
Volume34
Issue number3
Publication statusPublished - May 1997

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Chloride Channels
Pulmonary Artery
Endothelial Cells
Hypotonic Solutions
Chemical Stimulation
Hypertonic Solutions
Ionomycin
Fura-2
Vasoconstrictor Agents
Colforsin
Cell Size
Adenosine Triphosphate
Membranes

Keywords

  • Chloride channels
  • Endothelium
  • Patch clamp

ASJC Scopus subject areas

  • Physiology

Cite this

Multiple types of chloride channels in bovine pulmonary artery endothelial cells. / Nilius, Bernd; Szücs, G.; Heinke, Stefan; Voets, Thomas; Droogmans, Guy.

In: Journal of Vascular Research, Vol. 34, No. 3, 05.1997, p. 220-228.

Research output: Contribution to journalArticle

Nilius, B, Szücs, G, Heinke, S, Voets, T & Droogmans, G 1997, 'Multiple types of chloride channels in bovine pulmonary artery endothelial cells', Journal of Vascular Research, vol. 34, no. 3, pp. 220-228.
Nilius, Bernd ; Szücs, G. ; Heinke, Stefan ; Voets, Thomas ; Droogmans, Guy. / Multiple types of chloride channels in bovine pulmonary artery endothelial cells. In: Journal of Vascular Research. 1997 ; Vol. 34, No. 3. pp. 220-228.
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