Mezdour H, Monte G, Fruchart J C
Service de recherche sur les lipoprotéines et l'athérosclérose (Serlia), Inserm U-325 institut Pasteur de Lille, France.
Ann Biol Clin (Paris). 1994;52(2):95-102.
Transfer processes in plasma are determinant in cholesterol metabolism. In many species, including man, there is an alternative route for the disposal of cholesteryl esters (CE) in HDL via transfer to VLDL in exchange for triglycerides (TG), a process dependent on a hydrophobic 74 kDa glycoprotein called cholesteryl ester transfer protein (CETP). In vivo, cholesteryl esters transferred from HDL will contribute to LDL, to which VLDL is converted. Although the prevention of CE accumulation in HDL may enhance the ability of HDL to take up more cholesterol from tissues, high rates of transfer may also increase the risk for atheroma by increasing formation of atherogenic lipoproteins. Conversely, CE retained within HDL, if returned directly to the liver, would be expected to be beneficial. Moreover, in most conditions predisposing to atheroma, CETP activity is raised; whereas species with low or absent CETP activity are at low risk for atherosclerosis.
血浆中的转运过程在胆固醇代谢中起决定性作用。在包括人类在内的许多物种中，高密度脂蛋白（HDL）中的胆固醇酯（CE）可通过与极低密度脂蛋白（VLDL）交换甘油三酯（TG）的方式进行转运，这是一种通过名为胆固醇酯转运蛋白（CETP）的74 kDa疏水糖蛋白介导的替代途径。在体内，从HDL转运来的胆固醇酯会进入低密度脂蛋白（LDL），VLDL会转化为LDL。虽然防止CE在HDL中积累可能会增强HDL从组织中摄取更多胆固醇的能力，但高转运率也可能通过增加致动脉粥样硬化脂蛋白的形成而增加动脉粥样硬化的风险。相反，如果HDL中保留的CE直接返回肝脏，则有望带来益处。此外，在大多数易患动脉粥样硬化的情况下，CETP活性会升高；而CETP活性低或缺乏的物种患动脉粥样硬化的风险较低。
