【摘要】 目的探讨β-淀粉样蛋白(Aβ)通过氧化应激引起的细胞凋亡过程中,脑组织内抗氧酶活性的改变方式;并且通过过氧化氢酶(CAT)活性的变化,探讨过氧化物酶体在Aβ引起的氧化应激过程中的作用。方法将Aβ注射到大鼠海马,诱导细胞凋亡,在第3天和第7天观察超氧化物歧化酶(SOD)和CAT的活性变化。结果铜锌超氧化物歧化酶(CuZn-SOD)和CAT的活性明显低于对照组,但其mRNA的表达各组之间没有差异;从第3天到第7天,总SOD的活性没有改变,但伴随着CAT和CuZn-SOD活性的恢复,丙二醛(MDA)的含量减少,大鼠的学习、记忆能力有所恢复。结论抗氧化酶活性的降低并非mRNA转录水平下降,可能是酶蛋白被活性氧(ROS)氧化所致;CAT发挥了比总SOD更为重要的抗氧化作用;过氧化物酶体在Aβ引起的氧化应激过程中发挥了抗氧化作用。更多还原

【Abstract】 Objective To observe alternations of antioxidase activity in rat hippocampus in beta-amyloid peptide(Aβ)-induced,oxidative stress(OS)-dependent apoptosis.Methods The activities of superoxide dismutase(SOD) and catalase(CAT) were analysed on the third day and the 7th day after injecting Aβ into hippocampus.Results The declination of activities of Cu,Zn superoxide dismutase(CuZn-SOD) and CAT was observed while the expression of their mRNA was not changed.Although there was no change in total superoxide dismutase(T-SOD) activity,a declination of Maleic Dialdehyde(MDA) level and a recovery of learning and memory ability were found as the recovery of CAT and CuZn-SOD activity on the 7th day after Aβ injection.Conclusion These results suggest that the declination of antioxidase activities might be caused by oxidation of enzyme protein by reactive oxygen species(ROS).Catalase takes more important role than T-SOD in the antioxidation.Peroxisome has also been involved in the antioxidation during neuronal apoptosis.更多还原