Dietary α-linolenic acid supplementation alters skeletal muscle plasma membrane lipid composition, sarcolemmal FAT/CD36 abundance, and palmitate transport rates.
The cellular processes influenced by consuming polyunsaturated fatty acids remains poorly defined. Within skeletal muscle, a rate-limiting step in fatty acid oxidation is the movement of lipids across the sarcolemmal membrane, and therefore, we aimed to determine the effects of consuming flaxseed oil high in α-linolenic acid (ALA), on plasma membrane lipid composition and the capacity to transport palmitate. Rats fed a diet supplemented with ALA (10%) displayed marked increases in omega-3 polyunsaturated fatty acids (PUFAs) within whole muscle and sarcolemmal membranes (approximately five-fold), at the apparent expense of arachidonic acid (-50%). These changes coincided with increased sarcolemmal palmitate transport rates (+20%), plasma membrane fatty acid translocase (FAT/CD36; +20%) abundance, skeletal muscle triacylglycerol content (approximately twofold), and rates of whole body fat oxidation (~50%). The redistribution of FAT/CD36 to the plasma membrane could not be explained by increased phosphorylation of signaling pathways implicated in regulating FAT/CD36 trafficking events (i.e., phosphorylation of ERK1/2, CaMKII, AMPK, and Akt), suggesting the increased n-3 PUFA composition of the plasma membrane influenced FAT/CD36 accumulation. Altogether, the present data provide evidence that a diet supplemented with ALA increases the transport of lipids into resting skeletal muscle in conjunction with increased sarcolemmal n-3 PUFA and FAT/CD36 contents.
Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada; and.
Zane
Z
Chorner
Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada; and.
Pierre-Andre
PA
Barbeau
Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada; and.
Laura
L
Castellani
Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada; and.
David C
DC
Wright
Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
Adrian
A
Chabowski
Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada; and ghollowa@uoguelph.ca.
Graham P
GP
Holloway
D000284:Administration, Oral; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects / Q000502:physiology; D018955:CD36 Antigens / Q000378:metabolism*; D019587:Dietary Supplements; D008043:Linseed Oil / Q000008:administration & dosage; D050356:Lipid Metabolism / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008657:Metabolic Clearance Rate; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D010168:Palmitates / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism*; D017962:alpha-Linolenic Acid / Q000008:administration & dosage*
D018955:CD36 Antigens; C008132:Cd36 protein, rat; D010168:Palmitates; D017962:alpha-Linolenic Acid; D008043:Linseed Oil
fatty acid translocase; lipid transport; lipids/oxidation; membranes; omega-3 fatty acids