Activation and inhibition of reconstituted cardiac L-type calcium channels by palmitoyl-L-carnitine

Biochem Biophys Res Commun. 1996 Nov 12;228(2):252-8. doi: 10.1006/bbrc.1996.1649.


We have studied the effect of a palmitoyl-L-carnitine (L-PC) on single cardiac L-type Ca channels incorporated from porcine ventricular sarcolemma into planar lipid bilayers where we could control the concentration, intracellular and/or extracellular location, and duration of L-PC treatment. We found that 1.0 microM L-PC in either the intracellular or extracellular chamber caused an approximately 8 fold increase in channel open probability when measured within the first minute after L-PC addition. Higher concentrations of L-PC did not increase open probability to the same extent as 1.0 microM. In addition, we found that L-PC had biphasic effects on the open probability of L-type Ca channels, causing an increase in activity immediately after the addition of L-PC, but leading to a decrease in open probability after a few minutes. Higher concentrations of L-PC (10 microM) also caused a decrease in single-channel conductance from 26 to 21 pS (measured in 100 mM external Ba2+). The effects of L-PC were similar on both sides of the channels, suggesting that alterations in the physical properties of the membrane surrounding the channels may be responsible for the effects of L-PC. These changes in Ca channel activity may participate in the generation of abnormal electrical activity and arrhythmogenesis during ischemia.

Publication types

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

MeSH terms

  • Animals
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Calcium Channels, L-Type
  • Heart Ventricles
  • Ion Channel Gating
  • Kinetics
  • Lipid Bilayers
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Muscle Proteins / physiology
  • Myocardium / metabolism
  • Palmitoylcarnitine / pharmacology*
  • Patch-Clamp Techniques
  • Probability
  • Sarcolemma / physiology*
  • Swine


  • Calcium Channels
  • Calcium Channels, L-Type
  • Lipid Bilayers
  • Muscle Proteins
  • Palmitoylcarnitine