【摘要】 目的　研究维生素C(VC)在预防低密度脂蛋白 (LDL)氧化修饰中的作用。方法　在Cu2 +介导的无细胞体系中分别加入VC 10、5 0、10 0、2 0 0 μmol/L ,巨噬细胞体系中分别加入VC 5 0、10 0、2 0 0 μmol/L ,以维生素 ( 2 0 0 μmol/L)为阳性对照 ,不添加维生素C组 (VC0 )为阴性对照。测定荧光物质(lipofusin)、硫代巴比妥酸反应物质 (TBARS)、LDL电泳迁移率 (Rf)、氧化型低密度脂蛋白 (Ox LDL)、LDL氧化过程中的停滞时间等LDL的氧化修饰情况。结果　Cu2 +介导的无细胞体系中 ,高剂量VC( 10 0、2 0 0 μmol/L)在 3、6、9h均能发挥其抗氧化作用 ,抑制TBARS、Ox LDL生成 ;而VC低剂量 ( 10、5 0μmol/L)则无此作用 ,相反在 3h表现出促Ox LDL生成作用。在巨噬细胞体系中 ,高剂量组 ( 10 0、2 0 0μmol/L)能显著降低荧光物质、TBARS和LDL电泳迁移率 (Rf) ,延长LDL氧化过程中的停滞时间 ,并存在剂量反应关系。结论　VC在LDL氧化修饰中具有双重作用 ,低剂量时能促进LDL氧化 ,高剂量时表现出抗氧化作用。更多还原

【Abstract】 Objective To study the effect of vitamin C on preventing oxidative modification of low density lipoprotein cholesterol (LDL) in vitro Methods Different levels of vitamin C were added to two different systems of lipid peroxidation of LDL induced by either Cu 2+ or macrophage The level of VC in systems induced by Cu 2+ were 10,50,100 and 200 μmol/L respectively and by macrophage were 50,100,200 μmol/L respectively. Vitamin E (200 μmol/L) and VC 0 (0 μmol/L) were served as positive and negative control respectively The content of TBARS、Ox LDL、fluorescent compounds、electrophoretic mobility of LDL and the lag phage of oxidation of LDL were measured Results In the oxidative systems induced by Cu 2+ ,the groups with higher levels of VC (100,200 μmol/L) reduced the levels of TBARS,Ox LDL at 3、6、and 9 hour after adding Cu 2+ ,but low dose groups (10,50 μmol/L) had no the effects In the macrophage systems ,higher levels of VC (100,200 μmol/L) significantly reduced levels of fluorescent compounds and TBARS,and also lowered electrophoretic mobility of LDL and increased the lag phage of oxidation of LDL Conclusion Vitamin C has dual effect on oxidation of LDL Low dose treatment enhanced oxidation of LDL,but high doses has anti oxidative effects on LDL更多还原