Chait A, Brazg R L, Tribble D L, Krauss R M
Department of Medicine, University of Washington, Seattle 98195.
Am J Med. 1993 Apr;94(4):350-6. doi: 10.1016/0002-9343(93)90144-e.
To test whether low-density lipoprotein (LDL) from subjects with an atherogenic lipoprotein phenotype characterized by small, dense LDL (pattern B) demonstrates greater susceptibility to oxidative modification than LDL from subjects exhibiting primarily larger, more buoyant LDL particles (pattern A).
Measures of susceptibility to oxidative modification were compared in six density subfractions of LDL isolated from pattern A and pattern B subjects. Seven male and three female pattern A subjects and five male and two female pattern B subjects, classified on the basis of peak LDL particle size, were studied. Plasma lipid and lipoprotein levels, apolipoprotein B, mean LDL particle diameter, lag phase, and rate of oxidation after initiation of oxidation by copper sulfate were measured.
The lag time, a measure of resistance to oxidative modification, was inversely related (p < 0.001) to LDL density in both groups of subjects, without an independent effect of phenotype. The fraction that had the major LDL peak had a shorter lag time (p < 0.05) in pattern B than in pattern A. Pattern B subjects also demonstrated an increased rate of oxidation (p < 0.005) in fraction 1, which includes remnants of triglyceride-rich lipoproteins.
The increased atherogenic risk associated with the pattern B phenotype may result in part from increased concentrations of lipoprotein subpopulations that are relatively susceptible to oxidative modification.
检测以小而密低密度脂蛋白（LDL）为特征的致动脉粥样硬化脂蛋白表型（B型）受试者的LDL，与主要表现为更大、更具浮力的LDL颗粒（A型）受试者的LDL相比，是否对氧化修饰更敏感。
比较从A型和B型受试者分离出的LDL的六个密度亚组分对氧化修饰的敏感性。研究了根据LDL颗粒大小峰值分类的7名男性和3名女性A型受试者以及5名男性和2名女性B型受试者。测量了血浆脂质和脂蛋白水平、载脂蛋白B、平均LDL颗粒直径、滞后期以及硫酸铜引发氧化后的氧化速率。
两组受试者中，滞后期（氧化修饰抗性的一种测量指标）均与LDL密度呈负相关（p < 0.001），不受表型的独立影响。B型中具有主要LDL峰值的亚组分的滞后期比A型短（p < 0.05）。B型受试者在第1亚组分中也表现出氧化速率增加（p < 0.005），该亚组分包括富含甘油三酯的脂蛋白残余物。
与B型表型相关的动脉粥样硬化风险增加可能部分源于相对易受氧化修饰的脂蛋白亚群浓度增加。
