缺血再灌注期间大鼠脑线粒体的变化

Changes of rat brain mitochondria during ischemia and reperfusion

目的 观察局部脑缺血再灌注对大鼠脑线粒体呼吸链酶复合物活性、过氧化氢 (H2 O2 )产生量和脂质过氧化水平 (MDA含量 )的影响。方法 酶学方法 ,荧光法和比色法。结果 缺血 2 h后复合物 的活性即有明显下降 ,再灌注 30 m in至 4h均无恢复。酶重复合物 活性缺血时无明显变化 ,再灌注 30 m in开始下降 ,一直持续到再灌注 4h。酶复合物 活性在缺血与再灌注期间均无明显变化。缺血再灌注 1h时脑线粒体过氧化氢产生量明显上升 ,再灌注 2 h后又恢复到正常水平。 MDA含量则是在再灌注 2 h开始明显增高 ,4h时仍维持较高水平。结论 缺血再灌注可造成脑线粒体本身氧化损伤。

Objective The effect of reperfusion following 2 hour focal ischemia on rat brain mitochondria. Method Enzymology,Fluotometry,TBAR assay. Results Measurement of the individual respiratory chain complexes showed that the activity of complex Ⅱ was reduced immediately after 2 hour of ischemia,which continued during 0.5 to 1 hour of reperfusion;the activity of complex Ⅰ,which was normal after ischemia,decreased significantly by 0.5 to 4 hours of reperfusion. In contrast,complex IV activity was unaffected by ischemia or reperfusion. After 1 hour recirculation,we found the generation of H 2O 2 increased significantly. The level of lipid peroxidation (the content of MDA) didn ,t increase until 2 and 4 hour of reperfusion. Conclusion These data suggested rat brain mitochondria were damaged by oxidative stress during ischemic reperfusion.