Preferential uptake of dietary fatty acids in adipose tissue and muscle in the postprandial period
Preferential uptake of dietary fatty acids in adipose tissue and muscle in the postprandial period
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DOI：
10.2337/db06-0822
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发表时间：
2007-01-01
期刊：
影响因子：
7.7
通讯作者：
Frayn, Keith N.
中科院分区：
文献类型：
--
作者：
Bickerton, Alex S. T.;Roberts, Rachel;Frayn, Keith N.
尽管有一致的证据表明，脂肪酸输送和储存异常是胰岛素抵抗代谢缺陷的基础，但脂肪在脂肪组织和骨骼肌中储存的生理途径尚不清楚。我们使用稳定同位素标记和动静脉差异测量相结合的方法来阐明健康人的脂肪组织和骨骼肌餐后脂肪沉积的途径。将含有[U-C-13]棕榈酸酯的试验餐与静脉滴注[(2)H-2]棕榈酸酯联合标记血浆脂肪酸和vldl -甘油三酯。饮食（乳糜微粒）和vldl -甘油三酯都在脂肪组织和肌肉中被清除，尽管乳糜微粒-甘油三酯的提取比例更高。在脂肪组织中，在餐后有显著的血浆非酯化脂肪酸（NEFAs）摄取，但在禁食状态没有。然而，与乳糜微粒-甘油三酯脂肪酸相比，这是次要的。我们模拟了脂蛋白脂肪酶（LPL）释放的脂肪酸的命运。与血浆NEFAs相比，这些脂肪酸有明显的优先摄取。在肌肉中，有意想不到的证据表明lpl衍生的脂肪酸释放到血浆中。通过这种综合生理学方法，我们揭示了脂肪组织和骨骼肌中脂肪酸摄取途径的隐藏复杂性。
Despite consistent evidence that abnormalities of fatty acid delivery and storage underlie the metabolic defects of insulin resistance, physiological pathways by which fat is stored in adipose tissue and skeletal muscle are not clear. We used a combination of stable isotope labeling and arteriovenous difference measurements to elucidate pathways of postprandial fat deposition in adipose tissue and skeletal muscle in healthy humans. A test meal containing [U-C-13]palmitate was combined with intravenous infusion of [(2) H-2]palmitate to label plasma fatty acids and VLDL-triglyceride. Both dietary (chylomicron) and VLDL-triglyceride were cleared across adipose tissue and muscle, though with greater fractional extraction of the chylomicron-triglyceride. In adipose tissue there was significant uptake of plasma nonesterified fatty acids (NEFAs) in the postprandial but not the fasting state. However, this was minor in comparison with chylomicron-triglyceride fatty acids. We modeled the fate of fatty acids released by lipoprotein lipase (LPL). There was clear Preferential uptake of these fatty acids compared with plasma NEFAs. In muscle, there was unexpected evidence for release of LPL-derived fatty acids into the plasma. With this integrative physiological approach, we have revealed hidden complexities in pathways of fatty acid uptake in adipose tissue and skeletal muscle.