低密度脂蛋白,高脂血清对内皮细胞膜脂流动性的影响

实验用DPH荧光偏振技术测定经人低密度脂蛋白(LDL)及兔高脂血清(HRS)孵育的牛主动脉内皮细胞(EC)的膜脂微粘度。结果表明LDL孵育EC12小时导致细胞膜脂流动性下降,过氧化脂质(Lpo)含量增高;EC经HRS作用36小时后也发生相似的变化。形态观察证明EC胞浆中有大量脂滴样结构。结果提示高胆固醇含量的LDL和HRS可能通过增加膜的胆固醇含量而降低膜的流动性,高浓度Lpo可能也起重要作用。

Effects of low density lipoprotein and hyperlidemic sera on membrane fluidity of cultured endothelial cells

When cultured bovine aortic endothelial cells (EC) were incubated with LDL from men and with sera from hyperlipidemic rabbits, cellular lipid peroxide measured by the TBA method, and membrane fluidity assessed by the fluorescene polarization of the hydrophobic probe 1,6-diphenyl-1,3,5-hexatriene (DPH), it was found that the microviscosity of EC membrane increased when EC incubated with LDL for 12 hours and with hyperlipidemic sera for 36 hours; cellular lipid peroxides also increaeed, as compared with the control, at the same time large amounts of fat drop were found in the cytoplasma of EC. These results suggest that the LDL and hyperlipidemie sera can induce an increase of cholestesterol content on the membrane, then inducing a decline of membrane fluidity of EC. The lipid peroxides resulted from lipid peroxidation may play an important part in this process.