title: Different effects of palmitoyl-L-carnitine and palmitoyl-CoA on mitochondrial function in rat ventricular myocytes.
abstract: Although mitochondrial oxidative catabolism of fatty acid (FA) is a major energy source for the adult mammalian heart, cardiac lipotoxity resulting from elevated serum FA and enhanced FA use has been implicated in the pathogenesis of heart failure. To investigate the effects of intermediates of FA metabolism [palmitoyl-l-carnitine (Pal-car) and palmitoyl-CoA (Pal-CoA)] on mitochondrial function, we measured membrane potential (DeltaPsi(m)), opening of the mitochondrial permeability transition pore (mPTP), and the production of ROS in saponin-treated rat ventricular myocytes with a laser scanning confocal microscope. Our results revealed that 1) lower concentrations of Pal-car (1 and 5 muM) caused a slight hyperpolarization of DeltaPsi(m) [tetramethylrhodamine ethyl ester (TMRE) intensity increased to 115.5 +/- 5.4% and 110.7 +/- 1.6% of baseline, respectively, P < 0.05] but did not open the mPTP, 2) a higher concentration of Pal-car (10 microM) depolarized DeltaPsi(m) (TMRE intensity decreased to 61.9 +/- 12.2% of baseline, P < 0.01) and opened the mPTP (calcein intensity decreased to 70.7 +/- 2.8% of baseline, P < 0.01), 3) Pal-CoA depolarized DeltaPsi(m) without opening the mPTP, and 4) only the higher concentration of Pal-car (10 muM) increased ROS generation (2',7'-dichlorofluorescein diacetate intensity increased to 3.4 +/- 0.3-fold of baseline). We concluded that excessive exogenous intermediates of long-chain saturated FA may disturb mitochondrial function in different ways between Pal-car and Pal-CoA. The distinct mechanisms of the deteriorating effects of long-chain FA on mitochondrial function are important for our understanding of the development of cardiac diseases in systemic metabolic disorders.
authors.affiliation: Div. of Cardiology, Internal Medicine III, Hamamatsu Univ. School of Medicine, Hamamatsu 431-3192, Japan.
authors.forename: Hiromutsu
authors.initials: H
authors.lastname: Tominaga
authors.forename: Hideki
authors.initials: H
authors.lastname: Katoh
authors.forename: Keiichi
authors.initials: K
authors.lastname: Odagiri
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kawashima
authors.forename: Masao
authors.initials: M
authors.lastname: Saotome
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Urushida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Satoh
authors.forename: Hideharu
authors.initials: H
authors.lastname: Hayashi
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D006352:Heart Ventricles / Q000378:metabolism; D008297:Male; D053078:Membrane Potential, Mitochondrial; D018613:Microscopy, Confocal; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D010171:Palmitoyl Coenzyme A / Q000378:metabolism*; D010172:Palmitoylcarnitine / Q000378:metabolism*; D010539:Permeability; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species; D010171:Palmitoyl Coenzyme A; D010172:Palmitoylcarnitine; D016572:Cyclosporine; D000111:Acetylcysteine