急性等容性血液稀释对全脑缺血／再灌注大鼠海马细胞线粒体细胞色素c氧化酶活性的影响

The influence of acute normovolemic hemodilution on the activity of hippocampal mitochondria cytochrome c oxidase in global ischmic/reperfusion rats

目的从线粒体功能方面探讨急性等容性血液稀释acute normovolemic hemodilution，ANH）对全脑缺血／再灌注（ischemia／reperfusion，I／R）损伤大鼠的保护作用。方法24只雄性清洁SD大鼠，按随机数字表法随机分为4组：假手术组（SHAM组），I／R组，血液稀释至红细胞压积（hematocrit，Hct）30％后I／R组（HES30组），血液稀释至Hct40％后I／R组（HEs40组），每组6只。采用四血管法建立大鼠全脑I／R模型。夹闭双侧颈总动脉前0．5h，从股静脉抽取血液，同时输注等量6％羟乙基淀粉130／0．4氯化钠溶液（hydroxyethyls tarch 130／0．4 and sodium chloride injection，HES）行ANH。48h后处死大鼠，取大脑海马组织，分光光度仪测定细胞色素c氧化酶（cytochrome c oxidase，CcO）活性，逆转录聚合酶链式反应法（reverse transcription-polymerase chain reaction，RT-PCR）测定CcO亚基II（CcOⅡ）mRNA表达情况。结果I／R组CcO活性和CcO II mRNA表达分别为（0．021±0．012）和（0．079±0．009）（P〈0．01），与SHAM组比较分别降低至约7．580％和20．570％；HES40组CcO活性和CcOIImRNA表达分别为（0．120±0．032）和（0．180±0．033）（P〈0．01），与SHAM组比较，分别降低至约43．320％和46．870％；HES30组CcO活性和CcOIImRNA表达分别为（0．180±0．026）和（0．347±0．027）（P〈0．01），与SHAM组比较，分别降低至约64．980％和90．360％，与HES40组比较，下降程度较低（P〈0．01）。结论应用6％HES130／0．4ANH处理全脑I／R能升高线粒体内膜蛋白CcO活性及表达，且在Hct30％时达到最佳效果。适当的ANH处理促进线粒体功能和供能状态改善，具有脑保护作用。

Objective This study was designed to discuss the influence of the acute normovolemic hemodilution （ANH） in global cerebral ischemia/repeffusion （I/R） injury in terms of mitochondrial inner membrane. Methods 24 healthy male SD rats were randomly divided into 4 groups（each one 6 rats）： sham group（SHAM）, I/R group, ANH Hct30% and I/R group（HES30）, ANH Hct40% and I/R group （HES40）. Ischmia was established by four-vessel cerebral I/R model. Half an hour before bilateral carotid arteries were blocked, blood was drawn from the femoral vein, and in the meantime, the same amount of 6% hydroxyethyl starch （HES） solotion （130/0.4） was transfused. After 48 h, the rats were executed and hippocampus was taken out. The activity of cytochrome c oxidase（CcO） were measured by spectre photometry instrument, and the expression of CcO II mRNA were determianted by RT-PCR method. Results Compared with the SHAM group, the CcO activity and CcO II mRNA expression of I/R group were reduced to about 7.58% and 20.57%（0.0210±0.012 and 0.079±0.009, P〈0.01 ）. In HES40 group, they were reduced to about 43.32% and 46.87%（0.120±0.032 and 0.180±0.033, P〈0.01）, compared with the SHAM group. In HES30 group they were reduced to about 64.980% and 90.360% （0.180±0.026 and 0.347 ±0.027, P〈0.01） compared with the SHAM group and decreased less than HES40 group. Conclusions Application of 6%HES130/0.4 treatment of ANH can improve activity and expression of CcO in hippocampus mitochondria after cerebral I/R. Its protection achieves the optimal outcome when hemodiluted to Hct30%. The appropriate acute hemodilution elevates themitochondrial function and energy supply, improving the outcome of the global cerebral I/R.