【Abstract】  Objective  To explore the role of reactive oxygen species in the proliferation of ECV304 induced by AngⅡ.Methods  lines of human umbilical vein endothelial cell(ECV304) cultured in vivo were divided into three groups were treated by AngⅡ，Ang Ⅱ+N-acetyl-L-cysteine(NAC)，and normal culture medium.First we observed the proliferous effect of ECV304 induced by AngⅡ at different concentration with improved MTT and microscope.Then the contents of ROS(·OH) in three groups were detected by spectrophotometer.Results  ECV304 incubated with Ang Ⅱ(0.03125～1μmol/L) for 12 hours increase the proliferation rate (P<0.05 vs control group);It is significant that the negative correlation between proliferation rate and the content of ROS(·OH);NAC(10m免费论文网 【http://www.51lunwen.net】mol/L) can inhibit the proliferation of ECV304 induced by AngⅡ(P>0.05 vs control group).Conclusion  ECV304 induced by AngⅡ can produce ROS(·OH)，and the contents of ROS(·OH) increase with the prolongation of time and the enlargement of dose;Antioxidant NAC can inhibit the proliferation of ECV304 induced by AngⅡ，this effect may be related with reducing the content of ROS(·OH);ROS(·OH) may be one of the major mocleculars which play an important role in the signal transduction of ECV304 proliferation.

    【Key words】  NAC  Ang Ⅱ  ROS  ECV304  proliferation

    血管内皮是心血管疾病危险因子的靶点，其功能障碍构成许多心血管疾病的病理基础。认为血管自稳态的调节取决于血管内皮自身的氧化还原状态［１，２］。大量表明，氧化应激产生的各种活性氧(reactive oxygen species，ROS)对血管内皮具有细胞毒性作用，是许多心血管疾病发生的重要机制［3，4］。然而，新近报道氧化应激产生的ROS在一定量时，可作为血管内皮信号转导分子，参与调节细胞功能［5］。本研究以血管紧张素Ⅱ(AngⅡ)作为血管氧化应激的诱导剂，观察N-乙酰半胱氨酸(NAC)对人脐静脉内皮细胞株(ECV304)增殖作用的，探讨活性氧在血管紧张素Ⅱ诱导ECV304细胞增殖中的作用，为心血管疾病的防治提供新的依据，启示新药研发和的新途径。

    1  材料与方法

    1.1  材料  ECV304(人脐静脉内皮细胞株)购自院上海药物研究所；AngⅡ、NAC和MTT(批号9710)购自Sigma公司；特级无支原体新生牛血清购自杭州四季青生物工程材料研究所(批号20020114)；·OH测定试剂盒购自南京建成生物工程研究所(批号20030625)。

    1.2  方法

    1.2.1  实验分组  (1)AngⅡ处理组：a.不同作用时间(4h、12h和24h)；b.不同浓度(Ang Ⅱ终浓度分别为，0.03125μmol/L、0.0625μmol/L、0.125μmol/L、0.25μmol/L、0.5μmol/L和1μmol/L)；(2)NAC干预组：AngⅡ 1μmol/L+NAC 10mmol/L;(3)正常对照组：加入等量完全培养基。

    1.2.2  ECV304细 本文来自：免费论文网 [http://www.51lunwen.net]