人主动脉粥样硬化病变中修饰脂蛋白的研究

Modified lipoproteins in atherosclerotic lesions of human aorta

目的研究人粥样硬化病变主动脉中丙二醛（ＭＤＡ）和４羟基壬烯醛（ＨＮＥ）修饰载脂蛋白Ｂ（ａｐｏＢ）的分布特点、含量和理化特性，并与脂蛋白（ａ）［Ｌｐ（ａ）］和ａｐｏＢ的分布进行比较。方法应用免疫组织化学、电镜、免疫电镜以及生物化学等方法进行定性或定量分析。结果ＭＤＡ和ＨＮＥ－ａｐｏＢ在细胞外基质中的分布与Ｌｐ（ａ）和ａｐｏＢ一致，但在泡沫细胞内则有不同。ＭＤＡ－ａｐｏＢ和ＨＮＥ－ａｐｏＢ在泡沫细胞内呈环状、孔状分布，与蜡样色素相似。病变动脉内膜低密度脂蛋白的超微结构、化学成分及电泳行为均与体外修饰脂蛋白相似，其醛类修饰ａｐｏＢ含量明显高于无病变者。结论脂蛋白的氧化性修饰是动脉粥样硬化发生的必要条件。

Objective To study the distribution patterns,amount,as well as the physical and chemical properties of malondialdehyde (MDA) and 4 hydroxynonenal (HNE) modified apolipoprotein B (apo B) in atherosclerotic lesions of human aorta. The distribution patterns of MDA and HNE modified apo B were also compared with those of lipoprotein(a) and apo B. Methods Immunohistochemistry,electronic microscopy, immunoelectronic microscopic and biochemistry methods were used for qualitative and quantitative analysis. Results It was found that the distribution of MDA and HNE modified apo B coincided with Lp(a) and apo B in the extracellular matrix. While the distribution of MDA apo B and HNE apo B in foam cells appeared annular or particulate,similar to ceroids but different from that of Lp(a) or apo B. The physical and chemical properties of LDL from lesions on the intima were similar to those of in vitro modified LDL. In addition, a higher level of aldehyde modified LDL was extracted from the lesion areas than from normal intima. Conclusion Oxidative modification of apo B containing lipoproteins is necessary for atherogenesis.