The method for determination of serum lipid-free apolipoprotein concentration and its clinical application

高密度脂蛋白的颗粒大小是不均匀的，小的高密度脂蛋白颗粒比大的高密度脂蛋白颗粒更能有效地促进胆固醇从细胞膜外排。二维凝胶电泳法检测高密度脂蛋白，但耗时较长。本研究采用HPLC分离无脂载脂蛋白A-I，洗脱时间为51 min ~ 56 min。无脂载脂蛋白a - i的表位与HDL的表位相同，因为我们在ELISA系统中使用了载脂蛋白a - i的抗体。采用高效液相色谱法，在血液中加入SOU/ml的trasyrol，并在500 μ1的分离溶液中加入SOU/ml的trasyrol。经反复冻融试验，血清无脂载脂蛋白A-I浓度增加2倍，即使在4℃下保存也随时间变化。因此，血清样品立即用高效液相色谱处理或-80℃冷冻待用。与健康对照相比，冠心病患者无脂载脂蛋白A-I浓度在男性和女性中均显著升高。这些发现表明，胆固醇逆向转运在冠状动脉疾病中发生改变，无脂载脂蛋白a - i的测量可能是动脉粥样硬化的一个很好的标志。

It is known that HDL are heterogeneous in particle size and small HDL particle can promote more effectively cholesterol efflux from cell membrane than large HDL particle. Small HDL are detected by two-dimentional gel electrophoresis, but this method is time consuming. Lipid-free apo A-I in this study was separated by HPLC and was elutred from 51 min to 56 min. The epitope of lipid-free apo A-I is the same as tjhat of a HDL, because we used the antibody to apo A-I in the ELISA system. We added SOU/ml of trasyrol to blood and also to 500 μ1 of fractionated solutions by HPLC. Serum lipid-free apo A-I concentration increased two times by repeated freeze and thawing test and changed with time even in the store at 4℃. Thus, serum sample was immediately treated for HPLC or freezed at -80℃ until use.Serum lipid-free apo A-I concentrations significantly increased in patients with coronary heart disease compared to healthy controls in both males and females. These findings show that reverse cholesterol transport is altered in coronary heat disease and the measurement of lipid-free apo A-I may be a good marker for atherosclerosis.