小鼠腹腔巨噬细胞对糖基化脂蛋白的氧化修饰作用

Oxidation of Glucosylated Low Density Lipoprotein by Mouse Peritoneal Macrophages

目的通过研究脂蛋白糖基化后易被氧化修饰的性质来探讨胰岛素抵抗患者易于发生动脉粥样硬化的机理。方法用葡萄糖和低密度脂蛋白（ＬＤＬ）共同温育后得到糖基化脂蛋白（Ｇｌｕ－ＬＤＬ），并用琼脂糖电泳法和硫代巴比妥酸（ＴＢＡ）比色法鉴定糖基化的程度。用Ｃｕ２＋和小鼠腹腔巨噬细胞分别和Ｇｌｕ－ＬＤＬ共同温育，检测ＴＢＡ反应物（ＴＢＡＲＳ）含量及电泳迁移速度。结果Ｇｌｕ－ＬＤＬ和未糖基化ＬＤＬ分别与Ｃｕ２＋共同温育８ｈ后，二者ＴＢＡＲＳ含量具有显著性差异（Ｐ＜０．００１）；Ｇｌｕ－ＬＤＬ和ＬＤＬ分别与小鼠腹腔巨噬细胞共同温育２４及４８ｈ后，二者ＴＢＡＲＳ含量亦具有显著性差异（Ｐ＜０．０５），电泳迁移率也有相应改变。结论脂蛋白糖基化后易被氧化修饰，说明其稳定性下降。

Aim\ To study the mechanism of oxidative modification of glucosylated low density lipoprotein(Glu LDL) in pathogenesis of arterioselerosis. Methods\ By incubating LDL in the medium of 200 mmol/L glucose for 2￣4 days and measuring the glucosylative products by agarose electrophoresis and thio barbituric acid(TBA) chromotometry simutaneously. Cu 2+ and mouse peritoneal macrophages were co cultured with two kinds LDL and determined their difference in concentration of reaction product.\ Results\ After cultured with Cu 2+ for 8 h, the concentration of TBA reactive substance(TBARS) in Glu LDL were significantly higher than that in native LDL(P<0 001). The same result can be obtained when incubating with mouse peritoneal macrophages (P<0 05).\ Conclusion\ Glucosylative LDL was easily changed by oxidation, its stability was decreased in the process of oxidation.