Metabotropic Ca2+ channel-induced calcium release in vascular smooth muscle

Cell Calcium. 2007 Oct-Nov;42(4-5):513-20. doi: 10.1016/j.ceca.2007.04.010. Epub 2007 Jun 7.

Abstract

Contraction of vascular smooth muscle cells (VSMCs) depends on the rise of cytosolic [Ca(2+)] owing to either Ca(2+) influx through voltage-gated Ca(2+) channels of the plasmalemma or to receptor-mediated Ca(2+) release from the sarcoplasmic reticulum (SR). Although the ionotropic role of L-type Ca(2+) channels is well known, we review here data suggesting a new role of these channels in arterial myocytes. After sensing membrane depolarization Ca(2+) channels activate G proteins and the phospholipase C/inositol 1,4,5-trisphosphate (InsP(3)) pathway. Ca(2+) released through InsP(3)-dependent channels of the SR activates ryanodine receptors to amplify the cytosolic Ca(2+) signal, thus triggering arterial cerebral vasoconstriction in the absence of extracellular calcium influx. This metabotropic action of L-type Ca(2+) channels, denoted as calcium channel-induced Ca(2+) release, could have implications in cerebral vascular pharmacology and pathophysiology, because it can be suppressed by Ca(2+) channel antagonists and potentiated with small concentrations of extracellular vasoactive agents as ATP.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Arteries / metabolism
  • Arteries / physiology
  • Calcium / metabolism*
  • Calcium Channels, L-Type / physiology*
  • Calcium Signaling
  • Inositol 1,4,5-Trisphosphate / metabolism
  • Models, Biological
  • Muscle Contraction
  • Muscle, Smooth, Vascular / metabolism*
  • Muscle, Smooth, Vascular / physiology
  • Rats
  • Type C Phospholipases / metabolism

Substances

  • Calcium Channels, L-Type
  • Inositol 1,4,5-Trisphosphate
  • Type C Phospholipases
  • Calcium