研究了稀土离子对分离的线粒体产生活性氧(ROS)的影响.采用荧光光度法跟踪线粒体内H2O2生成的动力学,发现三种稀土离子(La^3+,Gd^3+,Yb^3+)均能降低线粒体H:0:的生成;用黄嘌呤-黄嘌呤氧化酶体系进一步证明稀土对超氧阴离子(·^-O2^-)存在清除作用,而对H2O2无清除作用;测定了稀土对线粒体ROS代谢酶(谷胱甘肽过氧化物酶和超氧化物歧化酶)的活性影响.结果表明,三种稀土离子对线粒体谷胱甘肽过氧化物酶的活性基本没有影响,而Gd^3+和Yb^3+稀土离子能明显抑制线粒体超氧化物歧化酶的活性.
The effects of lanthanides (Ln) on the production of reactive oxygen species (ROS) in isolated mitochondria were investigated by fluorescence assays upon incubation with Ln^3+. The results show that Ln^3+ (La^3+,Gd^3+,Yb^3+) could reduce the rates of overall ROS production. The results obtained from experiments on xanthine/xanthine oxidative enzyme system suggest that Ln^3+ ions can reduce the formation of ·02^- , but H2O2 did not react with Ln^3+. The influences of Ln^3+ on the activities of metabolize enzymes( GSH-Px and Mn-SOD) indicate that Ln^3+ could decrease the activity of Mn-SOD, but could not affect the activity of GSH-Px. The effects of Ln^3+ on cellular H2O2 level are discussed.