高浓度葡萄糖和低密度脂蛋白对血管内皮细胞的协同损伤及NO释放的影响

High glucose and LDL synergetic injure ECV304 and affect secretionof NO

目的探讨高浓度葡萄糖和低密度脂蛋白对血管内皮细胞有无协同损伤作用及两者对血管内皮细胞一氧化氮(NO)合成释放的影响.方法将葡萄糖和低密度脂蛋白(LDL)分别和共同加入培养的ECV304中,分别于作用24、48、72h进行形态学观察、台盼兰染色计算死亡率以及上清乳酸脱氢酶(LDH)、硫代巴比妥酸反应物质(TBARS)和NO-3/NO-2含量测定.结果联合作用净生成的TBARS远＞单独作用之和(约1.14～1.28倍),并呈现协同致死亡作用,而NO含量则随作用时间延长表现出先升高后下降的动态变化过程.结论高浓度葡萄糖和低密度脂蛋白对血管内皮细胞具有协同损伤作用,可能与高糖造成氧化应激,生成大量的活性氧(ROS)促进脂质过氧化以及损伤内皮NO系统有关,这可能是糖尿病高发动脉粥样硬化的部分机制.

Objective To explore whether high glucose and LDL could synergetic injure vascular endothelial cells （ECV304） and affect EC on secretion of NO. Methods Glucose（5.5,20,40M）and/or LDL（ 100 μg/ml）was added into the medium of cultured endothelial cells and incubated for 24, 48,72 hours respectively . The lipid peroxidation was assessed by the content of TBARS; cell necrosis with trypan blue staining and activity of LDH in the medium; NO3/NO2, which standing for the amount of NO, with nitrate reductase. Results （ 1 ）. High glucose could enhance lipid peroxidation and showed a position of dose - effect relationship; （2）. high glucose and LDL had synergetic effects on inducing necrosis of EC; （3） Both high glucose and LDL could unbalanced the metabolism of NO of endothelial cells; Conclusion High glucose and LDL could synergetic induce necrosis in endothelial ceils, which may be related to the cell - mediated LDL peroxidation enhanced by high glucose through oxidalon stress, and aggravate the pathogenesis of atherosclerosis in diabetes mellitus. This may partly attribute to the mechanism that diabetes mellitus mostly accompany by high risk of atherosclerosis.