Ca(2+) channels involved in endothelin-induced mitogenic response in carotid artery vascular smooth muscle cells

Am J Physiol Cell Physiol. 2002 Feb;282(2):C330-7. doi: 10.1152/ajpcell.00227.2001.

Abstract

Endothelin (ET)-1 activates two types of Ca(2+)-permeable nonselective cation channels (NSCC-1 and NSCC-2) and a store-operated Ca(2+) channel (SOCC) in rabbit internal carotid artery (ICA) vascular smooth muscle cells (VSMCs) in addition to the voltage-operated Ca(2+) channel (VOCC). These channels can be discriminated using the Ca(2+) channel blockers SK&F-96365 and LOE-908. SK&F-96365 is sensitive to NSCC-2 and SOCC, and LOE-908 is sensitive to NSCC-1 and NSCC-2. On the basis of sensitivity to nifedipine, a specific blocker of the L-type VOCC, VOCCs have a minor role in ET-1-induced mitogenesis. Both LOE-908 and SK&F-96365 inhibited ET-1-induced mitogenesis in a concentration-dependent manner, and the combination of LOE-908 and SK&F-96365 abolished it. The IC(50) values of these blockers for ET-1-induced mitogenesis correlated well with those of the ET-1-induced intracellular free Ca(2+) concentration responses. These results indicate that the inhibitory action of these blockers on ET-1-induced mitogenesis may be mediated by blockade of NSCC-1, NSCC-2, and SOCC. Collectively, extracellular Ca(2+) influx through NSCC-1, NSCC-2, and SOCC may be essential for ET-1-induced mitogenesis in ICA VSMCs.

MeSH terms

  • Acetamides / pharmacology
  • Animals
  • Calcium / metabolism
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / classification
  • Calcium Channels / physiology*
  • Carotid Arteries / cytology*
  • Carotid Arteries / drug effects*
  • Carotid Arteries / physiology
  • Electric Conductivity
  • Endothelin-1 / pharmacology*
  • Imidazoles / pharmacology
  • Intracellular Membranes / metabolism
  • Isoquinolines / pharmacology
  • Male
  • Mitosis / drug effects
  • Mitosis / physiology*
  • Muscle, Smooth, Vascular / cytology*
  • Muscle, Smooth, Vascular / drug effects*
  • Muscle, Smooth, Vascular / physiology
  • Osmolar Concentration
  • Patch-Clamp Techniques
  • Rabbits

Substances

  • Acetamides
  • Calcium Channel Blockers
  • Calcium Channels
  • Endothelin-1
  • Imidazoles
  • Isoquinolines
  • LOE 908
  • 1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole
  • Calcium