Palmitoleic acid induces the cardiac mitochondrial membrane permeability transition despite the presence of L-carnitine

Biochem Biophys Res Commun. 2015 Jul 17-24;463(1-2):29-36. doi: 10.1016/j.bbrc.2015.05.011. Epub 2015 May 14.

Abstract

Although palmitoleic acid (C16:1) is associated with arrhythmias, and increases in an age-dependent matter, the effects of L-carnitine, which is essential for the transport of long-chain fatty acids into the mitochondria, are unclear. It has been postulated that L-carnitine may attenuate palmitate (C16:0)-induced mitochondrial dysfunction and the apoptosis of cardiomyocytes. The aim of this study was to elucidate the activity of L-carnitine in the prevention of the palmitoleic acid-induced mitochondrial membrane permeability transition and cytochrome c release using isolated cardiac mitochondria from rats. Palmitoleoyl-CoA-induced mitochondrial respiration was not accelerated by L-carnitine treatment, and this respiration was slightly inhibited by oligomycin, which is an inhibitor of ATP synthase. Despite pretreatment with L-carnitine, the mitochondrial membrane potential decreased and mitochondrial swelling was induced by palmitoleoyl-CoA. In the presence of a combination of L-carnitine and tiron, a free radical scavenger, there was attenuated mitochondrial swelling and cytochrome c release following palmitoleoyl-CoA treatment. We concluded that palmitoleic acid, but not palmitate, induces the cardiac mitochondrial membrane permeability transition despite the presence of L-carnitine.

Keywords: Cytochrome c; Membrane potential; Palmitoleoyl-CoA; Palmitoyl-CoA; Swelling; Tiron.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / pharmacology
  • Animals
  • Carnitine / metabolism*
  • Carnitine / pharmacology*
  • Cytochromes c / metabolism
  • Fatty Acids, Monounsaturated / metabolism*
  • Fatty Acids, Monounsaturated / pharmacology*
  • Free Radical Scavengers / pharmacology
  • In Vitro Techniques
  • Male
  • Membrane Potential, Mitochondrial / drug effects
  • Membrane Potential, Mitochondrial / physiology
  • Mitochondria, Heart / drug effects*
  • Mitochondria, Heart / metabolism*
  • Mitochondrial Membrane Transport Proteins / drug effects*
  • Mitochondrial Membrane Transport Proteins / metabolism*
  • Mitochondrial Permeability Transition Pore
  • Mitochondrial Swelling / drug effects
  • Mitochondrial Swelling / physiology
  • Oxygen Consumption / drug effects
  • Palmitoyl Coenzyme A / pharmacology
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Fatty Acids, Monounsaturated
  • Free Radical Scavengers
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Permeability Transition Pore
  • Palmitoyl Coenzyme A
  • palmitoleic acid
  • 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt
  • Cytochromes c
  • Carnitine