中文摘要：

目的：研究尼古丁对人脐带间充质干细胞（HUCMSCs）超微结构及氧化应激的影响,探讨尼古丁诱导HUCMSCs凋亡的作用机制。方法：不同浓度尼古丁作用HUCMSCs后,透射电镜（TEM）观察HUCMSCs超微结构变化。分光光度计法检测HUCMSCs胞内过氧化氢酶（CAT）活性,黄嘌呤氧化酶法检测超氧化物歧化酶（SOD）活性,化学比色法检测还原型谷胱甘肽（GSH）活性,硫代巴比妥酸法检测丙二醛（MDA）含量。分光光度计法检测一氧化氮合酶（NOS）、诱生型一氧化氮合酶（iNOS）活性。结果：尼古丁作用HUCMSCs后,细胞内出现大量空泡状结构,粗面内质网扩张成池,线粒体嵴扩张。细胞内CAT、SOD、GSH活性均显著降低,脂质过氧化产物MDA含量显著增加,呈浓度依赖性。NOS、iNOS活性随尼古丁浓度上升而逐渐增加。结论：尼古丁可增加HUCMSCs的NOS、iNOS活性,使细胞发生凋亡结构改变,呈氧化应激状态,发生氧化-抗氧化系统失衡。

英文摘要：

Aim： To research the effects of nicotine on uhrastructures and oxidative stress in human umbilical cord mesenchymal stem cells （ HUCMSCs）, explore mechanism of nicotine-induced apoptosis on HUCMSCs. Methods： HUCMSCs were treated with different concentrations of nicotine, ultrastructures of HUCMSCs were observed by transmission electron microscopy （TEM）. The activity of catalase （CAT） was detected by visible spectrophotometer method, the activity of superoxide dismutase （SOD） was meas- ured by xanthine oxidase assay ,the activity of reduced glutathione（GSI-I） was detected by chemochroma-tometry, the content of malondialdehyde （MDA） was detected by thiobarbituric acid method. The activities of nitric oxide synthase（NOS） and inducible nitric oxide synthase （iNOS） were measured by ultraviolet spectrophotometer method. Results： After treated with nicotine, vacuole-like structures were observed in cytoplasm, the rough endoplasmic reticulum appeared to expand, and mitochondria exhibited an expand- ed ridge. The activities of CAT, SOD and GSH were significantly decreased, while the coment of MDA was significantly increased, in a dose-dependent manner. The activities of NOS and iNOS were signifi- cantly increased in a dose-dependent manner. Conclusion： Nicotine can increase the activities of NOS, iNOS, made cellular uhrastructures of apoptosis change, generate oxidative stress, induce the imbalance of oxidants -antioxidants.