Electrostimulation enhances FAT/CD36-mediated long-chain fatty acid uptake by isolated rat cardiac myocytes

Am J Physiol Endocrinol Metab. 2001 Oct;281(4):E704-12. doi: 10.1152/ajpendo.2001.281.4.E704.

Abstract

We investigated palmitate uptake and utilization by contracting cardiac myocytes in suspension to explore the link between long-chain fatty acid (FA) uptake and cellular metabolism, in particular the role of fatty acid translocase (FAT)/CD36-mediated transsarcolemmal FA transport. For this, an experimental setup was developed to electrically stimulate cardiomyocytes in multiple parallel incubations. Electrostimulation at voltages > or =170 V resulted in cellular contraction with no detrimental effect on cellular integrity. At 200 V and 4 Hz, palmitate uptake (measured after 3-min incubation) was enhanced 1.5-fold. In both quiescent and contracting myocytes, after their uptake, palmitate was largely and rapidly esterified, mainly into triacylglycerols. Palmitate oxidation (measured after 30 min) contributed to 22% of palmitate taken up by quiescent cardiomyocytes and, after stimulation at 4 Hz, was increased 2.8-fold to contribute to 39% of palmitate utilization. The electrostimulation-mediated increase in palmitate uptake was blocked in the presence of either verapamil, a contraction inhibitor, or sulfo-N-succinimidyl-FA esters, specific inhibitors of FAT/CD36. These data indicate that, in contracting cardiac myocytes, palmitate uptake is increased due to increased flux through FAT/CD36.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport / drug effects
  • CD36 Antigens / physiology*
  • Carbon Dioxide / analysis
  • Cells, Cultured
  • Electric Stimulation
  • Fatty Acids, Nonesterified / metabolism*
  • Heart / physiology*
  • Kinetics
  • Male
  • Membrane Glycoproteins / metabolism*
  • Myocardial Contraction
  • Myocardium / metabolism*
  • Organic Anion Transporters*
  • Oxidation-Reduction
  • Palmitates / pharmacology
  • Palmitic Acid / metabolism
  • Phloretin / pharmacology
  • Phospholipids / metabolism
  • Rats
  • Rats, Inbred Lew
  • Sarcolemma / metabolism
  • Succinimides / pharmacology
  • Triglycerides / metabolism
  • Verapamil / pharmacology

Substances

  • CD36 Antigens
  • Fatty Acids, Nonesterified
  • Membrane Glycoproteins
  • Organic Anion Transporters
  • Palmitates
  • Phospholipids
  • Succinimides
  • Triglycerides
  • sulfo-N-succinimidyl palmitate
  • Carbon Dioxide
  • Palmitic Acid
  • Verapamil
  • Phloretin