摘要目的 探讨不同程度和频率间歇低氧对人血管内皮细胞超氧化物歧化酶(SOD)和丙二醛(MDA)分泌水平的影响.方法 采用人脐静脉内皮细胞(ECV304细胞株)建立细胞模型.实验细胞株分为间歇正常氧组和间歇低氧(IH)组,根据低氧程度设立3个亚组:轻度低氧组、中度低氧组和重度低氧组,根据低氧频率不同设立5个亚组.分别以不同程度和不同频率间歇低氧环境暴露细胞,采用酶联免疫法测定细胞胚基中SOD和MDA水平.结果 不同程度间歇低氧组中MDA水平均高于间歇正常氧组(P＜0.01),随低氧程度增加呈逐渐升高(P＜0.01).SOD水平在3个不同程度IH组均低于间歇正常氧组(P＜0.01),SOD随IH程度减低逐渐下降(P＜0.01).SOD水平在IH频率为40和20次/h之间差异无统计学意义(P＞0.05),随IH频率降低,SOD水平逐渐降低,至9.2次/h达到最高,至6.3次/h再次下降(P＜0.01).MDA水平在IH频率为40次/h与20次/h间差异无统计学意义(P＞0.05),之后随IH频率降低,MDA水平逐渐升高,至9.2次/h达到最低,至6.3次/h再次轻度上升(P＜0.01).正常氧与3个不同程度IH组,SOD与MDA均值呈负相关(r=0.932,P＜0.01).不同频率IH暴露,5个不同频率IH组SOD与MDA均值呈负相关(r=0.832,P＜0.01).结论 间歇低氧暴露人脐动脉内皮细胞氧化应激反应增强,抗氧化能力减低,其减低和增高具有低氧程度依赖性.不同频率间歇低氧暴露,脐动脉上皮细胞氧化应激反应增强,抗氧化能力减低随频率减低逐渐增强和减低的趋势.低氧程度对氧化应激反应的影响高于频率,间歇低氧暴露上皮细胞出现氧化和抗氧化平衡的失调.

abstractsObjective To investigate the effect of different degrees and frequencies of intermittent hypoxia on levels of superoxide dismutase(SOD)and malondialdehyde(MDA)in vascular endothelial cells.Methods Umbilical vein endothelial cell ECV304 was used to set up the cell model.The experiment consisted of 1 control group(normal air)and 8 experimental groups,in which the cells were exposed to 3 different degrees and 5 different frequencies of intermittent hypoxia.The levels of SOD and MDA were measured by ELISA in cytoblastema.ResulIs The levels of MDA in the 3 different degree intermittent hypoxia groups were higher than that in the control group(P＜0.01)The levels of SOD in the 3 different degree hypoxia groups were lower than that in the control group(P＜0.01).The level of SOD decreased and the level of MDA increased with decreasing degrees of hypoxia(P＜0.01).The level of MDA was not different between the groups with hypoxia for 40 times/h and 20 times/h(P＞0.05).With decreased hypoxia frequency,the level of MDA increased;the MDA level of the 9.2 times/h subgroup was the lowest, but the level of MDA increased slightly when the frequency reached 6.3 times/h(P＜0.01).When hypoxia frequency decreased.the level of SOD decreased,and the level of the 9.2 times/h group was the highest,but the level of SOD decreased again when the hypoxia frequency reached 6.3 times/h(P＜0.01).The level of SOD was negatively correlated to that of MDA under different degrees of hypoxia exposure(r= 0.932,P＜0.01).and the level of SOD was negatively correlated to that of MDA under difierent frequencies of exposure(r=0.832,P＜0.01).Conclusion Intermittent hypoxia activates oxidative stress in endothelial cells,leading to increase of reactive oxygen species,with the antioxidant capacity impaired.The decrease and increase of oxidative stress reaction depended on the degree of hypoxia and were correlated to the frequency of hypoxia.With exposure to intermittent hypoxia,the balalice between oxidative stress and antioxidative system in endothelial cells was disturbed.