Removal of Mg2+ inhibition of cardiac ryanodine receptor by palmitoyl coenzyme A

FEBS Lett. 1994 Oct 3;352(3):285-90. doi: 10.1016/0014-5793(94)00969-4.

Abstract

45Ca2+ fluxes and planar bilayer recordings indicated that the fatty acid metabolite palmitoyl coenzyme A, but not free coenzyme A or palmitic acid, stimulated the cardiac ryanodine receptor channel of pig heart sarcoplasmic reticulum. Palmitoyl CoA reactivated channels inhibited by concentrations of cytoplasmic free Mg2+ in the physiological range. Reactivation by palmitoyl CoA in the presence of Mg2+ was stimulated by myoplasmic free Ca2+ in the micromolar range. Acyl coenzyme A derivatives may be utilized by cardiac muscle cells to compensate for the severe Mg2+ inhibition of ryanodine receptors which would otherwise leave Ca2+ stores unresponsive to Ca2+ and to other cytosolic ligands involved in signal transduction.

Publication types

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

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium / pharmacology
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Heart Ventricles
  • Kinetics
  • Lipid Bilayers
  • Magnesium / pharmacology*
  • Muscle Proteins / drug effects
  • Muscle Proteins / physiology*
  • Myocardium / metabolism*
  • Palmitoyl Coenzyme A / pharmacology*
  • Ryanodine Receptor Calcium Release Channel
  • Sarcoplasmic Reticulum / metabolism*
  • Swine
  • Time Factors

Substances

  • Calcium Channels
  • Lipid Bilayers
  • Muscle Proteins
  • Ryanodine Receptor Calcium Release Channel
  • Palmitoyl Coenzyme A
  • Magnesium
  • Calcium