Jeukendrup A E, Saris W H, Wagenmakers A J
Nutrition Research Center, Department of Human Biology, Maastricht University, The Netherlands.
Int J Sports Med. 1998 May;19(4):231-44. doi: 10.1055/s-2007-971911.
This is the first part in a series of three articles about fat metabolism during exercise. In this part the mobilization of fatty acids and their metabolism will be discussed as well as the possible limiting steps of fat oxidation. It is known for a long time that fatty acids are an important fuel for contracting muscle. After lipolysis, fatty acids from adipose tissue have to be transported through the blood to the muscle. Fatty acids derived from circulating TG may also be used as a fuel but are believed to be less important during exercise. In the muscle the IMTG stores may also provide fatty acids for oxidation after stimulation of hormone sensitive lipase. In the muscle cell, fatty acids will be transported by carrier proteins (FABP), and after activation, fatty acyl CoA have to cross the mitochondrial membrane through the carnitine palmytoyl transferase system, after which the acyl CoA will be degraded to acetyl CoA for oxidation. The two steps that are most likely to limit fat oxidation are fatty acid mobilization from adipose tissue and transport of fatty acids into the mitochondria along with mitochondrial density and the muscles capacity to oxidize fatty acids.
这是关于运动期间脂肪代谢的三篇系列文章中的第一篇。在这部分内容中，将讨论脂肪酸的动员及其代谢，以及脂肪氧化可能的限制步骤。长期以来人们都知道，脂肪酸是收缩肌肉的重要燃料。脂肪分解后，来自脂肪组织的脂肪酸必须通过血液运输到肌肉。循环中的甘油三酯衍生的脂肪酸也可作为燃料，但据信在运动期间其重要性较低。在肌肉中，肌内甘油三酯储存也可在激素敏感性脂肪酶受到刺激后为氧化提供脂肪酸。在肌肉细胞中，脂肪酸将由载体蛋白（FABP）运输，激活后，脂肪酰辅酶A必须通过肉碱棕榈酰转移酶系统穿过线粒体膜，之后酰基辅酶A将被降解为乙酰辅酶A进行氧化。最有可能限制脂肪氧化的两个步骤是脂肪组织中脂肪酸的动员以及脂肪酸进入线粒体的运输，同时还有线粒体密度和肌肉氧化脂肪酸的能力。
