Fragoso Y D, Brown A J
Department of Molecular & Cell Biology, University of Aberdeen, Scotland.
Sao Paulo Med J. 1998 Jul-Aug;116(4):1753-9. doi: 10.1590/s1516-31801998000400003.
To investigate the transport of alpha-tocopherol in lipoproteins of rabbits under normal diet and under acute loading of cholesterol.
Two New Zealand White rabbits were fed 14C-alpha-tocopherol acetate in a single oral dose and the recovery of radiolabel in lipoproteins and plasma was monitored. Low density lipoprotein (LDL) from these animals was obtained and labeled with [3H] cholesteryl ester. Three other rabbits were injected with this double-labeled LDL in the native form; while three other animals received this LDL in the acetylated form.
Plasma clearance, liver uptake and levels of radiolabel in high density lipoprotein (HDL) of animals injected with 14C[3H]acetyl LDL were significantly higher than those in animals injected with 14C[3H]native LDL. Larger particles of HDL, rich in apolipoprotein E (apoE) carried significantly higher levels of both labels in rabbits injected with acetylated LDL.
These results provide evidence for in vivo mechanisms of "reverse alpha-tocopherol transport", analogous to "reverse cholesterol transport".
研究正常饮食及急性胆固醇负荷情况下，家兔脂蛋白中α-生育酚的转运情况。
给两只新西兰白兔单次口服14C-α-生育酚醋酸酯，监测脂蛋白和血浆中放射性标记物的回收情况。获取这些动物的低密度脂蛋白（LDL）并用[3H]胆固醇酯进行标记。另外三只兔子注射天然形式的这种双标记LDL；而另外三只动物接受乙酰化形式的这种LDL。
注射14C[3H]乙酰化LDL的动物，其血浆清除率、肝脏摄取率以及高密度脂蛋白（HDL）中的放射性标记物水平显著高于注射14C[3H]天然LDL的动物。在注射乙酰化LDL的家兔中，富含载脂蛋白E（apoE）的较大HDL颗粒携带的两种标记物水平均显著更高。
这些结果为“α-生育酚逆向转运”的体内机制提供了证据，类似于“胆固醇逆向转运”。
