深低温对全脑缺血大鼠海马线粒体功能的影响

目的 研究深低温对全脑缺血大鼠海马线粒体功能的影响,并探讨其在深低温脑保护机制中的作用.方法 建立大鼠体外循环模型,实验动物按随机数字表法分成对照组(8只)、常温缺血组(8只)和低温缺血组(8只).提取海马组织线粒体,观察线粒体呼吸功能、线粒体琥珀酸脱氢酶(succinate dehydrogenase,SDH)、细胞色素氧化酶(cytochrome oxidese,CCO)活性、线粒体膜流动性、线粒体内游离Ca2+和丙二醛(MDA)含量的变化.结果 常温缺血组线粒体Ca2+与MDA含量均较对照组显著升高(P<0.01),而低温缺血组Ca2+与MDA含量较常温缺血组显著降低(P<0.05).常温缺血组呼吸Ⅲ态(R3)、呼吸Ⅳ态(R4)、磷氧比(P/O)及氧化磷酸化效率(OPR)均较对照组显著降低(P<0.05).低温缺血组R3、R4、P/O、OPR均较常温缺血组显著回升(P<0.05).常温缺血组线粒体膜流动性较对照组显著降低(P<0.01),而低温缺血组膜流动性较常温缺血组显著升高(P<0.05).常温缺血组线粒体SDH与CCO活性均较对照组显著降低(P<0.01),而低温缺血组SDH与CCO活性均较常温缺血组显著升高(P<0.05).结论 深低温对全脑缺血大鼠海马线粒体功能具有保护作用.

Abstract：

Objective To detect the effect of deep hypothermia on the function of mitochondria in hippocampus after global ischemia in rats and to explore the protection mechanism. Methods The animal model of cardiopulmonary bypass (CPB) was established in rats that were then randomly divided into three groups,ie,control group,normothermia ischemia group and hypothermia ischemia group,eight rats per group.The mitochondria was extracted from the hippocampus of each rats for observing the mitochondrial respiratory function,the activities of succinate dehydrogenase (SDH),the cytochrome oxidese(CCO),the lnembrane fluidity and the content of intramitochondria free calcium and MDA. Resuits The content of intramitochondria free calcium and MDA in the normothermia ischemia group was increased significantly compared to the control group and that in the hypothermia ischemia group wag decreased significantly compared with the normothermia ischemia group(P<0.05).Respiratory state Ⅲ (R3),respiratory state IV(R4),P/O ratio and oxidative phosphorylation (OPR) in the normothermia ischemia group were decreased significantly compared to the control group (P<0.05).R3,R4,P/O ratio and OPR in the hypothermia ischemia group were increased significantly compared with the normothermia ischemia group (P<0.05).Membrane fluidity in the normothermia ischemia group wag decreased significantly compared to the control group (P<0.01),while that in the hypothermia ischemia group was increased significantly compared with the normothermia ischemia group(P<0.05).The activities of SDH and CCO in the normothermia ischemia group were decreased significantly compared to the control group (P<0.01),while those in the hypothermia ischemia group were increased significantly compared with the normothermia ischemia group (P<0.05). Conclusion Profound hypothermia exerts a protective effect on the function of mitochondria in the hippocampus after global ischemia in rats.

Effect of profound hypothermia on function of mitochondria in hippocampus after global ischemia in rats

Objective To detect the effect of deep hypothermia on the function of mitochondria in hippocampus after global ischemia in rats and to explore the protection mechanism. Methods The animal model of cardiopulmonary bypass (CPB) was established in rats that were then randomly divided into three groups,ie,control group,normothermia ischemia group and hypothermia ischemia group,eight rats per group.The mitochondria was extracted from the hippocampus of each rats for observing the mitochondrial respiratory function,the activities of succinate dehydrogenase (SDH),the cytochrome oxidese(CCO),the lnembrane fluidity and the content of intramitochondria free calcium and MDA. Resuits The content of intramitochondria free calcium and MDA in the normothermia ischemia group was increased significantly compared to the control group and that in the hypothermia ischemia group wag decreased significantly compared with the normothermia ischemia group(P<0.05).Respiratory state Ⅲ (R3),respiratory state IV(R4),P/O ratio and oxidative phosphorylation (OPR) in the normothermia ischemia group were decreased significantly compared to the control group (P<0.05).R3,R4,P/O ratio and OPR in the hypothermia ischemia group were increased significantly compared with the normothermia ischemia group (P<0.05).Membrane fluidity in the normothermia ischemia group wag decreased significantly compared to the control group (P<0.01),while that in the hypothermia ischemia group was increased significantly compared with the normothermia ischemia group(P<0.05).The activities of SDH and CCO in the normothermia ischemia group were decreased significantly compared to the control group (P<0.01),while those in the hypothermia ischemia group were increased significantly compared with the normothermia ischemia group (P<0.05). Conclusion Profound hypothermia exerts a protective effect on the function of mitochondria in the hippocampus after global ischemia in rats.