Vasomotion has chloride-dependency in rat mesenteric small arteries

Pflugers Arch. 2008 Nov;457(2):389-404. doi: 10.1007/s00424-008-0532-3. Epub 2008 Jun 7.


The possibility that Ca(2+)-activated Cl(-) conductances (CaCCs) contribute to oscillations in vascular tone (vasomotion) is tested in isolated mesenteric small arteries from rats where cGMP independent (I (Cl(Ca))) and cGMP-dependent (I (Cl(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. Cl(-) (o) replacement with aspartate blocked vasomotion while 36mM SCN(-) (o) (substituted for Cl(-)) was sufficient to inhibit vasomotion. Oscillations in tone, membrane potential, and [Ca(2+)](i) disappeared with 36mM SCN(-). DIDS and Zn(2+) blocked I (Cl(Ca,cGMP)) but not I (Cl(Ca)). Vasomotion was not sensitive to DIDS and Zn(2+), and DIDS and Zn(2+) induce vasomotion in arteries without endothelium. The vasomotion in the presence of DIDS and Zn(2+) was sensitive to 36mM SCN(-) (o). The anion substitution data indicate that Cl(-) is crucial for the V (m) and [Ca(2+)](i) oscillations underlying vasomotion. The Cl(-) channel blocker data are consistent with both CaCCs being important.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / pharmacology
  • Animals
  • Aspartic Acid / metabolism
  • Calcium Signaling
  • Chloride Channels / drug effects
  • Chloride Channels / metabolism*
  • Chlorides / metabolism*
  • Dose-Response Relationship, Drug
  • Glycolates / pharmacology
  • Hydrogen-Ion Concentration
  • Male
  • Membrane Potentials
  • Mesenteric Arteries / drug effects
  • Mesenteric Arteries / metabolism*
  • Muscle, Smooth, Vascular / metabolism
  • Myocytes, Smooth Muscle / metabolism
  • Niflumic Acid / pharmacology
  • Norepinephrine / pharmacology
  • Rats
  • Rats, Wistar
  • Sarcoplasmic Reticulum / metabolism
  • Thiocyanates / metabolism
  • Vasoconstriction* / drug effects
  • Vasoconstrictor Agents / pharmacology
  • Vasodilation* / drug effects
  • Zinc / metabolism


  • Chloride Channels
  • Chlorides
  • Glycolates
  • Thiocyanates
  • Vasoconstrictor Agents
  • Aspartic Acid
  • Niflumic Acid
  • MK 473
  • Zinc
  • thiocyanate
  • 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
  • Norepinephrine