Tomkin Gerald H, Owens Daphne
Diabetes Institute of Ireland, Beacon Clinic, Sandyford, Dublin 18, Ireland.
Int J Vasc Med. 2012;2012:784536. doi: 10.1155/2012/784536. Epub 2011 Oct 5.
The B-containing lipoproteins are the transporters of cholesterol, and the evidence suggests that the apo B48-containing postprandial chylomicron particles and the triglyceride-rich very low density lipoprotein (VLDL) particles play an important part in the development of the plaque both directly and indirectly by their impact on LDL composition. The ratio of dietary to synthesised cholesterol is variable but tightly regulated: hence intervention with diet at best reduces serum cholesterol by <20% andusually <10%. Statins are the mainstay of cholesterol reduction therapy, but they increase cholesterol absorption, an example of the relationship between synthesis and absorption. Inhibition of cholesterol absorption with Ezetimibe, an inhibitor of Niemann Pick C1-like 1 (NPC1-L1), the major regulator of cholesterol absorption, increases cholesterol synthesis and hence the value of adding an inhibitor of cholesterol absorption to an inhibitor of cholesterol synthesis. Apo B48, the structural protein of the chylomicron particle, is synthesised in abundance so that the release of these particles is dependent on the amount of cholesterol and triglyceride available in the intestine. This paper will discuss cholesterol absorption and synthesis, chylomicron formation, and the effect of postprandial lipoproteins on factors involved in atherosclerosis.
含B的脂蛋白是胆固醇的转运蛋白，有证据表明，含载脂蛋白B48的餐后乳糜微粒颗粒和富含甘油三酯的极低密度脂蛋白（VLDL）颗粒，通过对低密度脂蛋白（LDL）成分的影响，在斑块形成过程中直接或间接地发挥重要作用。饮食胆固醇与合成胆固醇的比例是可变的，但受到严格调控：因此，饮食干预最多只能使血清胆固醇降低<20%，通常<10%。他汀类药物是降低胆固醇治疗的主要药物，但它们会增加胆固醇吸收，这体现了合成与吸收之间的关系。依泽替米贝是一种抑制胆固醇吸收的药物，它能抑制胆固醇吸收的主要调节因子尼曼-匹克C1样1蛋白（NPC1-L1），但会增加胆固醇合成，因此将胆固醇吸收抑制剂与胆固醇合成抑制剂联合使用具有重要意义。乳糜微粒颗粒的结构蛋白载脂蛋白B48大量合成，因此这些颗粒的释放取决于肠道中可利用的胆固醇和甘油三酯的量。本文将讨论胆固醇吸收与合成、乳糜微粒的形成以及餐后脂蛋白对动脉粥样硬化相关因素的影响。
