Dietary {alpha}-linolenic acid supplementation alters skeletal muscle plasma membrane lipid composition, sarcolemmal FAT/CD36 abundance and palmitate transport rates
AJP Regulatory Integrative and Comparative Physiology
Published online on November 02, 2016
Abstract
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 of movement 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 n-3 PUFAs within whole muscle and sarcolemmal membranes (~5-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 (~2-fold) 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, Akt), suggesting the increased n-3 PUFA composition of the plasma membrane influenced FAT/CD36 accumulation. Altogether, the present data provides 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.