低密度、氧化低密度脂蛋白对内皮细胞分泌内皮素的影响

目的 观察低密度脂蛋白（LDL）、氧化低密度脂蛋白（ox-LDL）对内皮细胞分泌内皮素（ET）的影响，以及后者在体外是否对前者具有氧化修饰作用.方法 采用不同浓度的LDL、ox-LDL及LDL＋ox-LDL与脐静脉内皮细胞株ECV-304进行孵育，24 h后分别收集细胞和上清液，采用放免分析法测定ET含量.结果 LDL、ox-LDL均能促进内皮细胞合成、分泌ET，但ox-LDL的作用更显著，而LDL＋ox-LDL组上清ET浓度大于两者单独作用之和.结论 LDL、ox-LDL均能促进内皮细胞合成、分泌ET，但后者的作用更为明显，且在体外对LDL具有氧化修饰作用。

Effect of low density lipoprotein and oxidized low density lipoprotein on the secretion of endothelin in endothelial cells

ObjectiveTo investigate the effect of low density lipoprotein(LDL) and oxidized low density lipoprotein(ox-LDL) on the secretion of endothelin(ET) and whether LDL to be oxidized and modified by ox-LDL in vitro.MethodsEndothelial cell strain ECV-304 was incubated with different concentration of LDL(50 and 100 mg/L),ox-LDL(50 and 100 mg/L) or LDL+ox-LDL(50mg/L) for 24 hours,then cells and cultured medium were collected.ET in cells and cultured medium were detected with radioimmunoassay.ResultsBoth of LDL and ox-LDL enhanced the secretion of ET in cultured endothelial cells;the effect of ox-LDL was more markedly than LDL.LDL+ox-LDL had a greater effect than any of the two lipoproteins alone.ConclusionLDL and ox-LDL may have the ability to promote the secretion of ET in cultured endothelial cells and LDL can be oxidized and modified by ox-LDL in vitro.