Heideman C L, Hoff H F
Biochim Biophys Acta. 1982 Jun 11;711(3):431-44. doi: 10.1016/0005-2760(82)90057-1.
Apolipoprotein A-I was quantitated by electroimmunoassay in buffer-soluble fractions of both grossly normal intima and raised atherosclerosis lesions of the human aorta. The mean value for apolipoprotein A-I content in microgram/mg tissue dry weight of normal intima (12 cases) was 0.71 +/- 0.10 S.E. and of aortic plaques (19 cases) was 0.64 +/- 0.40 S.E. When compared to the buffer-extractable apolipoprotein B content measured in these same cases from both regions, the ratio of apolipoprotein B to apolipoprotein A-I was approximately 6. No apolipoprotein A-I was measurable in tunica media. Following differential ultracentrifugation into d less than 1.063, d 1.063-1.21 and d greater than 1.21 fractions, the distributions of recovered apolipoprotein A-I were, respectively: 1, 94 and 5% for normal intima, 19, 31 and 50% for plaques and 1, 89 and 10% for plasma. Characterization of a chromatographically purified d 1.063-1.21 or HDL density fraction from fatty-fibrous plaques demonstrated particles of between 60 and 120 A diameter, a characteristic apolipoprotein A-I band by SDS-polyacrylamide gel electrophoresis, and a precipitin peak closely migrating with that for plasma HDL by two-dimensional immunoelectrophoresis. The d greater than 1.21 density fraction from plaques isolated by affinity chromatography on a Sepharose-anti-apolipoprotein A-I column contained small amounts of phospholipid but no measurable cholesterol. The d 1.063-1.21 density fraction from plaques showed a significant increase in percent free cholesterol and phospholipid contents and decrease in cholesteryl ester content relative to plasma HDL. This increase in free cholesterol could represent evidence for an anti-atherogenic mechanism wherein infiltrated HDL removes cholesterol together with phospholipid from the arterial wall.
采用免疫电泳法对人主动脉大体正常内膜和动脉粥样硬化病变处的缓冲液可溶部分中的载脂蛋白A-I进行定量分析。正常内膜（12例）每毫克组织干重中载脂蛋白A-I含量的平均值为0.71±0.10标准误，主动脉斑块（19例）为0.64±0.40标准误。与在这两个区域相同病例中测得的缓冲液可提取载脂蛋白B含量相比，载脂蛋白B与载脂蛋白A-I的比值约为6。中膜中未检测到载脂蛋白A-I。经差速超速离心分为密度小于1.063、1.063 - 1.21和大于1.21的组分后，回收的载脂蛋白A-I的分布分别为：正常内膜中为1%、94%和5%，斑块中为19%、31%和50%，血浆中为1%、89%和10%。对来自脂肪纤维斑块的经色谱纯化的密度为1.063 - 1.21或HDL密度组分进行特性分析，结果显示其颗粒直径在60至120埃之间，通过SDS - 聚丙烯酰胺凝胶电泳呈现特征性的载脂蛋白A-I条带，并且通过二维免疫电泳其沉淀素峰与血浆HDL的沉淀素峰紧密迁移。通过在琼脂糖 - 抗载脂蛋白A-I柱上进行亲和层析分离得到的斑块密度大于1.21的组分含有少量磷脂，但未检测到胆固醇。相对于血浆HDL，斑块密度为1.063 - 1.21的组分中游离胆固醇和磷脂含量百分比显著增加，胆固醇酯含量降低。游离胆固醇的这种增加可能代表了一种抗动脉粥样硬化机制的证据，即浸润的HDL将胆固醇与磷脂一起从动脉壁中清除。
