ROLE OF FREE FATTY-ACIDS AND INSULIN IN DETERMINING FREE FATTY-ACID AND LIPID OXIDATION IN MAN
ROLE OF FREE FATTY-ACIDS AND INSULIN IN DETERMINING FREE FATTY-ACID AND LIPID OXIDATION IN MAN
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DOI：
10.1172/jci115005
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发表时间：
1991-01-01
影响因子：
15.9
通讯作者：
DEFRONZO, RA
中科院分区：
文献类型：
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作者：
GROOP, LC;BONADONNA, RC;DEFRONZO, RA
胰岛素可抑制血浆FFA氧化（通过输注C-14-棕榈酸酯测定）和净脂质氧化（间接量热法）。本研究旨在检查这些胰岛素介导的脂质代谢效应是否是由于循环FFA水平下降或激素对FFA/脂质氧化的直接作用所致。9名受试者参加了两次正常血糖胰岛素钳夹试验，使用和不使用肝素。在每次胰岛素钳夹研究期间，以两种速率（4和20 mU/m2）输注胰岛素。用间接量热法和3-H-3-葡萄糖和C-14-棕榈酸酯输注进行研究。在对照研究期间，血浆FFA分别从610 +/- 46降至232 +/- 42至154 +/- 27 μ mol/L。当输注肝素时，基础血浆FFA浓度保持恒定。在对照研究期间，FFA/脂质氧化速率与血浆FFA浓度的下降平行下降。在胰岛素/肝素研究期间，血浆C-14-FFA氧化保持不变，而净脂质氧化降低。总之，当血浆FFA浓度通过肝素输注保持不变时，胰岛素对FFA周转和处置没有直接影响。因此，这些结果表明，血浆FFA氧化主要由血浆FFA浓度决定，而净脂质氧化受血浆FFA和胰岛素水平的调节。
Plasma FFA oxidation (measured by infusion of C-14-palmitate) and net lipid oxidation (indirect calorimetry) are both inhibited by insulin. The present study was designed to examine whether these insulin-mediated effects on lipid metabolism resulted from a decline in circulating FFA levels or from a direct action of the hormone on FFA/lipid oxidation. Nine subjects participated in two euglycemic insulin clamps, performed with and without heparin. During each insulin clamp study insulin was infused at two rates, 4 and 20 mU/m2 . min for 120 min. The studies were performed with indirect calorimetry and 3-H-3-glucose and C-14-palmitate infusion. During the control study plasma FFA fell from 610 +/- 46 to 232 +/- 42 to 154 +/- 27 mu-mol/liter, respectively. When heparin was infused basal plasma FFA concentration remained constant. During the control study, FFA/lipid oxidation rates decreased in parallel with the fall in the plasma FFA concentration. During the insulin/heparin study, plasma C-14-FFA oxidation remained unchanged while net lipid oxidation decreased. In conclusion, when the plasma FFA concentration is maintained unchanged by heparin infusion, insulin has no direct effect on FFA turnover and disposal. These results thus suggest that plasma FFA oxidation is primarily determined by the plasma FFA concentrations, while net lipid oxidation is regulated by both the plasma FFA and the insulin level.