七氟醚后处理对大鼠心肌缺血再灌注损伤线粒体呼吸功能的影响

Effect of Sevoflurane Postconditioning on Mitochondrial Respiratory Function during Ischemia-reperfusion in Rat Hearts

目的评价七氟醚后处理对大鼠离体心脏缺血再灌注时线粒体呼吸功能及酶活性的影响。方法雄性SD大鼠36只,随机分为3组(n=12),对照组(C)、缺血再灌注组(I/R)、七氟醚后处理组(S-post)。采用Langendorff制备心肌缺血/再灌注模型,离体心脏缺血40min,再灌注2h。七氟醚后处理组在复灌初15min灌注经3%七氟醚饱和的K-H液15min后续灌正常K-H液105min。记录各组平衡末(T1)及复灌末(T2)的心率(HR)、左室发展压(LVDP)、左室舒张末压力(LVEDP)及左心室内压最大上升速率(+dp/dtmax)等血流动力学参数;取复灌末左心室心肌组织,用透射电镜观察心肌细胞超微结构的变化;用汉莎氧电极测定心肌线粒体3态呼吸(State3)、呼吸控制比(Respiratory Control Ratio,RCR)及烟酰胺腺嘌呤二核苷酸氧化酶(NADH-OX)、琥珀酸氧化酶(Suc-OX)、细胞色素C氧化酶(Cytc-OX)等酶活性变化。结果高组内比较:T2与T1相比血流动力学、3态呼吸、RCR及酶活性变化有统计学意义(P<0.05)组间比较T1各组间血流动力学、3态呼吸、RCR及酶活性变化无统计学意义(P>0.05);T2对照组与其余两组相比血流动力学、3态呼吸、RCR及酶的活性变化均有统计学意义(P<0.05),S-post组与I/R组相比血流动力学、3态呼吸、R CR及酶的活性变化均有统计学意义(P<0.05)。结论七氟醚后处理能够有效保护大鼠缺血再灌注时心肌线粒体呼吸功能及Suc-OX、NADH-OX、Cytc-OX呼吸酶的活性,维持呼吸链电子传递及氧化磷酸化正常进行,从而减轻大鼠心肌缺血再灌注损伤。

Objective To evaluate the effect of sevoflurane posteonditioning on mitochondrial respiration function during ischemia-reperfusion（I/R）in isolated rat hearts. Methods 36 male Sprague-Dawley rats were randomly divided into 3 groups（n=12）, the control group （C）, ischemia-reperfusion group （I/R）, sevoflurane postconditioning group （S-post）. Using Langendorff to prepare myocardial ischemia/reperfusion model, isolated hearts were subjected to ischemia for 40 min followed and reperfusion for 2 h. In group S-post,the hearts were perfused with K-H solution saturated with 3.0%sevoflurane for 15 min in the early reperfusion then followed normal K-H solution 105 min. At the end of the balance late and reperfusion time, recorded heart rate （HR）, left ventricular developed pressure （LVDP）, left ventricular end-diastolic pressure （LVEDP） and left ventricular pressure maximal rate of rise （＋dp/dtmax） and other hemodynamic parameters. At 2 h of reperfusion ,the changes of ultrastructure of cardiomyocytes were observed by transmission electron microscope. Myocardial mitochondrial respiratory state 3 （State3）, respiratory control ratio （Respiratory Control Ratio, RCR） and nicotinamide adenine dinucleotide oxidase （NADH-OX）, succinate oxidase （Suc-OX） cytochrome C oxidase （Cytc-OX） and other enzyme activity were measured by the oxygen electrode. Results comparison within the group： T2 compared with T1 hemodynamics, 3-state respiration, RCR and enzyme activity were statistically significant （P〈0.05）. Comparison between groups： among the groups at T1, hemodynamics, 3-state respiration, RCR and enzyme activity were not statistically significant （P〉0.05）;T2 the control group compared with the other two groups hemodynamics, 3-state respiration, RCR and enzyme activity were statistically significant （P〈0.05）, S-post group compared with the I/R group hemodynamics, 3-state respiration, RCR and enzyme activity were statistically significant （P〈0.05）. Conclusion sevoflurane posteonditioning can effectively protect mitochondrial respiratory function and Suc-OX, NADH-OX, Cytc-OX respiratory enzyme activity, maintain respiratory chain electron transport and oxidative phosphorylation normally, thereby reducing myocardial ischemia-reperfusion injury.