缺氧缺血性脑损伤新生猪海马皮层细胞色素C氧化酶活性变化

目的　研究缺氧缺血性脑损伤 (HIBD)新生猪海马皮层细胞色素C氧化酶 (COX)活性变化。方法　50只 3d新生猪随机分为实验组和对照组 (假手术组 )。实验组制成HIBD模型后置空气中 ,根据在空气中放置时间分 4组 (0h组 ,2 4h组 ,48h组 ,72h组 ) ,每组 10只。每只新生猪分离左侧海马皮层线粒体 ,用分光光度计测定其COX活性 ;采用SDS -PAGE分析线粒体蛋白改变。结果　 1.0h组COX活性与对照组无显著性差异(P >0 .0 5) ,再灌注时开始下降 ,2 4h组活性最低 (P <0 .0 5) ,然后逐渐回升 ,但 72h组仍未恢复至对照水平(P <0 .0 5)。 2 .SDS -PAGE示 2 4h组、48h组和 72h组线粒体蛋白成分和结构与对照组比较有明显差异。结论　HIBD后再灌注线粒体COX活性下降 ,线粒体蛋白成分和结构发生明显变化 ,此为线粒体能量代谢障碍的直接原因 ,也是HIBD中线粒体对神经元凋亡起关键作用的理论基础。

The changes of cytochrome coxidase activity in hippocampal cortex of neonatal pig after hypoxic-ischemic brain damage

Objective To study the cytochrome coxidase (COX) activity in hippocampal cortex of neonatal pigs after hypoxic-ischemic brain damage (HIBD).Methods Fifty pigs of three days old were randomly assigned to four experimental groups and a control group.The experimental groups were established the HIBD animal model,and put into normoxic condition.According to the normoxic condition exposure time,they were divided into four groups (0 h,24 h,48 h and 72 h).Sham operations were performed on control group.Mitochondria of neurons of left hippocampal cortex was isolated from each pig.and the COX activity was examined by spectrophotometer.SDS-PAGE was used to analyze the patterns of the mitochondrial protein.Results 1.There was no difference in COX activity of hippocampal cortex between 0 h group and control group ( P <0.05);It began to decline with reperfusion,and the lowest point of which was in 24 h group( P <0.05);Then it began to restore in 48 h group and 72 h group( P <0.05),but in 72 h guoup it did not reach the level of control group.2.The patterns of the mitochondrial protein by SDS-PAGE in the 24 h,48 h and 72 h group were different from that of control group.Conclusions The COX activity of neonatal animals declined,the composition and structure of mitochondrial protein changed evidently during reperfusion period after HIBD,these added to evidences that mitochondria played a key role in enuronal apoptosis following cerebral hypoxic ischemia.