Capell W H, Zambon A, Austin M A, Brunzell J D, Hokanson J E
Department of Medicine, University of Washington, Seattle 98195, USA.
Arterioscler Thromb Vasc Biol. 1996 Aug;16(8):1040-6. doi: 10.1161/01.atv.16.8.1040.
A predominance of small LDL particles (subclass phenotype B), as determined by gradient-gel electrophoresis is found among patients with myocardial infarction. Despite physical differences in phenotype A and B particles, differences in lipid composition of particles in these phenotypes have yet to be reported in an unselected population of males and females. The present study used lipid/apoB ratios to analyze the amount of lipid per LDL particle, isolated by density-gradient ultracentrifugation, in 70 healthy subjects. Relative to apoB, the LDL particles from phenotype B subjects were found to contain less free cholesterol (0.391 +/- 0.05 versus 0.465 +/- 0.05; mean +/- SD; P < .001), phospholipid (1.26 +/- 0.2 versus 1.43 +/- 0.2; P < .001), and cholesteryl ester (1.97 +/- 0.1 versus 2.11 +/- 0.2; P < .001) than particles from phenotype A subjects. The amount of triglyceride per LDL particle did not differ between the two phenotypes (0.410 +/- 0.1 versus 0.406 +/- 0.1; P = NS) despite higher plasma triglyceride levels in the phenotype B subjects. LDL size and buoyancy were positively correlated with particle free cholesterol, phospholipid, and cholesteryl ester but not with particle triglyceride. These data suggest that the physical properties of LDL from subjects with phenotype A and B reflect their lipid composition. The compositional differences between LDL particles of the two phenotypes may provide new insight into the increased risk of myocardial infarction in subjects with small, dense LDL.
通过梯度凝胶电泳测定发现，心肌梗死患者中存在大量小LDL颗粒（亚类表型B）。尽管A和B表型颗粒在物理性质上存在差异，但在未经过选择的男性和女性群体中，尚未有关于这些表型颗粒脂质组成差异的报道。本研究使用脂质/载脂蛋白B比率分析了70名健康受试者中通过密度梯度超速离心分离的每个LDL颗粒的脂质含量。相对于载脂蛋白B，发现B表型受试者的LDL颗粒所含游离胆固醇（0.391±0.05对0.465±0.05；平均值±标准差；P<0.001）、磷脂（1.26±0.2对1.43±0.2；P<0.001）和胆固醇酯（1.97±0.1对2.11±0.2；P<0.001）比A表型受试者的颗粒少。尽管B表型受试者的血浆甘油三酯水平较高，但两种表型之间每个LDL颗粒的甘油三酯含量没有差异（0.410±0.1对0.406±0.1；P=无显著性差异）。LDL大小和浮力与颗粒游离胆固醇、磷脂和胆固醇酯呈正相关，但与颗粒甘油三酯无关。这些数据表明，A和B表型受试者的LDL物理性质反映了它们的脂质组成。两种表型的LDL颗粒之间的组成差异可能为小而密LDL受试者心肌梗死风险增加提供新的见解。
