茶多酚对轻度低压缺氧引起的小鼠肺自由基代谢异常的保护作用.

目的观察天然抗氧化剂茶多酚(Teapolyphenols,TP)对重复轻度低压缺氧引起的小鼠肺自由基代谢异常的保护作用.方法42只雄性昆明种小鼠随机分为3组对照组(A);1500m低压缺氧组(B)和TP保护组(C).低压舱暴露时间为2h/d,3d/wk,共8wk.上舱暴露前,C组灌胃给予TP100mg/kg,另2组给予蒸馏水.末次实验后次日将小鼠断头处死,迅速取出肺组织.测定肺超氧化物歧化酶(SOD)活性和丙二醛(MDA)、一氧化氮(NO)含量.另外,用免疫组化法对肺组织CuZn-SOD和诱生型NO合酶(iNOS)的含量进行定性观察.结果与对照组比较,重复轻度低压缺氧暴露使肺MDA水平和NO含量明显升高(P<0.01),但TP防护组肺MDA生成和NO含量恢复正常.B组肺SOD活性有升高趋势,该组细支气管上皮细胞CuZn-SOD酶含量和支气管上皮细胞及肺间质血管内皮细胞和平滑肌细胞的iNOS酶含量明显增加.重复给予TP使这些酶的异常表达恢复正常.结论天然抗氧化剂茶多酚对重复轻度低压缺氧引起的肺自由基代谢异常具有保护作用.

Protective Effects of Tea Polyphenols on Mild Hypobaric Hypoxia Induced Pulmonary Free Radical Metabolic Disorder in Mice

Objective To observe the protective effects of natural antioxidant tea polyphenols(TP) on repeated mild hypobaric hypoxia induced pulmonary free radical metabolic disorder in mice. Method Fourty two male Kunming mice were randomly divided into three groups(n=14 each):normal control(A);1500 m mild hypobaric hypoxia(B) and TP protection group(C).The exposure time in hypobaric chamber was 2 h/d,3 d/wk,8 wk in total.Before hypoxic exposure,TP was orally given to group C at a dose of 100 mg/kg,while distilled water was given to the other two groups.After experiment,the mice were decapitated on the next day and the lung was quickly removed.The malondialdehyde(MDA) concentration,superoxide dismutase(SOD) activity and nitric oxide(NO) content were measured.In addition, Cu,Zn SOD and inducible NO synthase(iNOS) enzymatic contents in lung were qualitatively examined by immunohistochemical assaying. Result Compared with the control group, pulmonary MDA concentration and NO content were significantly increased after chro nic mild hypobaric hypoxic exposures(P<0.01),but the MDA formation and NO generation in TP protection group were restored to normal.Pulmonary SOD activity in group B tended to increase.Cu,Zn SOD expression in endothelial cells of bronchioli and iNOS contents in endothelial cells of bronchioli and endothelial cells and smooth muscle cells in pulmonary interstitial vessels were significantly elevated after repeated mild hypobaric hypoxic exposure.These enzymatic abnormal expressions regained to normal after administration of TP. Conclusion Natural antioxidant TP had protective effects on repeated mild hypobaric hypoxia induced pulmonary free radical metabolic disorder.