Lipid metabolism in contracting muscle - HSL takes a back seat

摘要

All cells of the body store triglycerides, which are composed of three fatty acids conjugated to a glycerol backbone. Triglycerides are located within discrete intracellular organelles called lipid droplets that are populated with surface proteins that regulate diverse functions, including triglyceride metabolism. While adipose tissue stores the most triglyceride, a significant amount accumulates inside muscle cells. There has been a sustained interest in understanding what regulates the breakdown and synthesis of this intra-myocellular triglyceride (IMTG), primarily because it is an important metabolic substrate that accounts for ~25% of energy production during moderate intensity exercise (Romijn et al. 1993).