Beisiegel U
Medical Clinic, University Hospital Eppendorf, Hamburg, Germany.
Eur Heart J. 1998 Feb;19 Suppl A:A20-3.
Hyperlipidaemias are important risk factors for coronary heart disease. To prevent and treat the different forms of hyperlipidaemias it is important to understand lipoprotein metabolism. The current knowledge on lipoprotein metabolism is based on many different biochemical and metabolic studies which are summarized here for a clinically orientated overview. Exogenous fat is transported in chylomicrons from the intestine to the liver. After entry in the blood stream the chylomicrons are hydrolyzed by the endothelial-bound lipoprotein lipase. The chylomicron remnants are rapidly taken up into the liver via the LDL receptor and the LDL receptor-related protein. Apolipoprotein E and lipoprotein lipase are the recognition signals for these receptors. The liver utilizes the exogenous fat and can release surplus lipids via VLDL into the blood. The VLDL are another substrate for lipoprotein lipase. The remaining VLDL remnants can either be taken up into the liver or are hydrolyzed to LDL. LDL delivers cholesterol to all body cells via the LDL receptor. The level of LDL cholesterol is regulated by the amount of LDL receptor, and defects in the LDL receptor molecule lead to hypercholesterolaemia. The level of triglyceride-rich remnants is regulated by the amount and activity of lipoprotein lipase and defects in this enzyme cause mixed hyperlipidaemias. Both these forms of hyperlipoproteinaemias are the most frequent and represent major risk factors for arteriosclerosis.
高脂血症是冠心病的重要危险因素。为了预防和治疗不同类型的高脂血症，了解脂蛋白代谢非常重要。目前关于脂蛋白代谢的知识基于许多不同的生化和代谢研究，在此进行总结以提供一个临床导向的概述。外源性脂肪通过乳糜微粒从肠道运输到肝脏。进入血流后，乳糜微粒被内皮结合的脂蛋白脂肪酶水解。乳糜微粒残粒通过低密度脂蛋白受体和低密度脂蛋白受体相关蛋白迅速被肝脏摄取。载脂蛋白E和脂蛋白脂肪酶是这些受体的识别信号。肝脏利用外源性脂肪，并可通过极低密度脂蛋白将多余的脂质释放到血液中。极低密度脂蛋白是脂蛋白脂肪酶的另一种底物。剩余的极低密度脂蛋白残粒要么被肝脏摄取，要么被水解为低密度脂蛋白。低密度脂蛋白通过低密度脂蛋白受体将胆固醇输送到所有身体细胞。低密度脂蛋白胆固醇的水平由低密度脂蛋白受体的数量调节，低密度脂蛋白受体分子的缺陷会导致高胆固醇血症。富含甘油三酯的残粒水平由脂蛋白脂肪酶的数量和活性调节，该酶的缺陷会导致混合性高脂血症。这两种类型的高脂蛋白血症最为常见，是动脉硬化的主要危险因素。
