Lipid Metabolism in Muscle

Abstract

The sections in this article are: Supply and Cellular Uptake of Upids in Skeletal Muscles Albumin‐Bound Fatty Acids Fatty Acids in Circulating Lipoproteins Skeletal Muscle Fatty Acid Uptake Fatty Acid Metabolism in the Skeletal Muscle Cell Activation and Oxidation of Fatty Acids Intramuscular Triacylglycerols Supply and Utilization of Upids During Exercise Albumin‐Bound Fatty Acids in Plasma during Exercise Circulating Lipoprotein‐Triacylglycerols as a Potential Source of Fatty Acids during Exercise Contribution of Intramuscular Triacylglycerols to Fatty Acid Oxidation during Exercise Relative Contribution of Various Sources of Lipids to Overall Fatty Acid Utilization during Exercise Gender Differences in Lipid Utilization during Exercise Effect of Training on Skeletal Muscle Lipid Utilization Advantages of Enhanced Lipid Utilization by Trained Muscles during Exercise Possible Causes of Increased Lipid Consumption by Trained Muscles during Exercise Utilization of Plasma‐Borne Fatty Acids by Trained Muscles Circulating Lipoproteins as an Additional Source of Lipids for Trained Muscles Utilization of Intramuscular Triacylglycerols in Endurance‐Trained Muscles Regulation of Fatty Acid Release from Intramuscular Triacylglycerols in Trained Muscles Effect of Diet on Muscle Lipid Metabolism High‐Carbohydrate vs. High‐Fat Diets in Relation to Physical Performance Shift from Carbohydrate to Lipid Utilization by High‐Fat Diet Source of Lipid for Muscles during High‐Fat Diet Feeding Possible Mechanisms Underlying Increased Muscular Lipid Utilization during High‐Fat Feeding Interrelationship Between Muscular Carbohydrate and Lipid Metabolism The Glucose–Fatty Acid, or Randle, Cycle The Existence of the Randle Cycle in Skeletal Muscle Possible Mechanisms Underlying the Glucose‐Fatty Acid Cycle in Skeletal Muscle A Role for Malonyl CoA in Fuel Selection in Skeletal Muscle Cells Defects in the Skeletal Muscle Fatty Acid Oxidative Pathway Concluding Remarks

Expression of hormone-sensitive lipase and its regulation by adrenaline in skeletal muscle

“…acylglycerol stores can be mobilized by catecholamines [8,9] and by exercise [2,3,10,11]. The exercise-induced decrease in muscle triacylglycerol concentration can be reduced by β-adrenergic blockade, and must accordingly be due to some extent to sympathetic stimulation [12].…”

“…While it seems that the intramuscular triacylglycerols constitute a dynamic energy store, the enzymic regulation of triacylglycerol breakdown in muscle is poorly understood [3,11,13,14]. Skeletal muscle contains three different types of triacylglycerol lipases [2,3].…”

“…Skeletal muscle contains three different types of triacylglycerol lipases [2,3]. One is a lysosomal lipase with an in itro pH optimum of 5.…”

“…The energy content of this triacylglycerol store is higher than the energy content of the muscle glycogen pool [3]. The muscle triacylglycerol concentration is increased by a high-fat diet [4] and in poorly controlled diabetes [5,6], and is inversely related to whole-body insulin action [7].…”

Acute Regulation of Fatty Acid Uptake Involves the Cellular Redistribution of Fatty Acid Translocase

“…LCFAs are a key oxidizable substrate for skeletal muscle (see Ref. 7), and because of its mass (40% of body weight) and highly variable metabolic rate, skeletal muscle is a principal site for the removal of LCFAs from the circulation. Moreover, LCFA uptake and metabolism can be increased rapidly in contracting muscle (16,17).…”