Both cellular cholesterol metabolism imbalance and apoptosis are related to th e development of atherosclerosis. To investigate the relationship between the ce llular cholesterol metabolism and apoptosis, the porcine aortic smooth muscle ce lls were cultured with medium 199 containing 15 mg/L oxidized low density lipo protein (Ox-LDL) for 72 h, the ratio of cellular cholesteryl ester to total cholesterol increased from 26.2% to 64.1%, and Ox-LDL induced accumulation o f cellular ch olesteryl ester in a concentration dependent manner in the cells. It indicated t hat the vascular smooth muscle cells had transformed to foam cells. In addition, cells incubated with oxidized low density lipoprotein had characteristic of apo ptosis, as determined by fluorescence microscope, laser scanning confocal micros cope and flow cytometry. From this findings, it was speculated that the inducti on of apoptosis may be related to the raise of the ratio of cellular cholesteryl este r to total cholesterol besides oxidation of low density lipoprotein in vascular smooth muscle cells.%细胞内胆固醇代谢的失衡和细胞凋亡都与动脉粥样硬化的发生有关.为了研究两者之间的关系,我们把猪的主动脉平滑肌细胞与15 mg/L氧化低密度脂蛋白共同孵育 72 h,发现细胞内胆固醇酯与总胆固醇的比值由26.2%增加到64.1%,并且细胞内胆固醇酯的积聚有剂量依赖关系,表明细胞已经转化为平滑肌源性的泡沫细胞.另外,使用荧光显微镜、激光共聚焦显微镜和流式细胞仪分别发现,与氧化低密度脂蛋白共孵育的细胞有典型的凋亡形态改变.从实验可以推测,由氧化低密度脂蛋白诱导的平滑肌细胞凋亡,除了低密度脂蛋白氧化的因素外,也可能与细胞内胆固醇酯与总胆固醇的比值升高有关.
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