Vasomotion has chloride-dependency in rat mesenteric small arteries

  • D. M. Briggs Boedtkjer
  • V. V. Matchkov
  • E. Boedtkjer
  • H. Nilsson
  • C. Aalkjaer
Ion Channels, Receptors and Transporters

DOI: 10.1007/s00424-008-0532-3

Cite this article as:
Boedtkjer, D.M.B., Matchkov, V.V., Boedtkjer, E. et al. Pflugers Arch - Eur J Physiol (2008) 457: 389. doi:10.1007/s00424-008-0532-3

Abstract

The possibility that Ca2+-activated Cl conductances (CaCCs) contribute to oscillations in vascular tone (vasomotion) is tested in isolated mesenteric small arteries from rats where cGMP independent (ICl(Ca)) and cGMP-dependent (ICl(Ca,cGMP)) chloride conductances are important. The effect of anion substitution and Cl channel blockers on noradrenaline (NA)-stimulated tension in isometrically mounted mesenteric arteries and for chloride conductance of smooth muscle cells isolated from these arteries were assessed electrophysiologically. Clo replacement with aspartate blocked vasomotion while 36mM SCNo (substituted for Cl) was sufficient to inhibit vasomotion. Oscillations in tone, membrane potential, and [Ca2+]i disappeared with 36mM SCN. DIDS and Zn2+ blocked ICl(Ca,cGMP) but not ICl(Ca). Vasomotion was not sensitive to DIDS and Zn2+, and DIDS and Zn2+ induce vasomotion in arteries without endothelium. The vasomotion in the presence of DIDS and Zn2+ was sensitive to 36mM SCNo. The anion substitution data indicate that Cl is crucial for the Vm and [Ca2+]i oscillations underlying vasomotion. The Cl channel blocker data are consistent with both CaCCs being important.

Keywords

Ca2+-dependent Cl channels Vasomotion Thiocyanate Aspartate DIDS Zinc 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • D. M. Briggs Boedtkjer
    • 1
  • V. V. Matchkov
    • 1
  • E. Boedtkjer
    • 1
  • H. Nilsson
    • 1
  • C. Aalkjaer
    • 1
  1. 1.Department of PhysiologyInstitute of Physiology and Biophysics, University of AarhusAarhus CDenmark

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