丹参多酚酸对大鼠缺血心肌线粒体酶的影响

目的:探讨丹参多酚酸对大鼠心肌缺血再灌注过程中线粒体Na+,K+-ATP酶和Ca2+-ATP酶的影响。方法:采用健康Wistar大鼠(n=40)建立Langendorff离体心脏灌注模型,并分为4组。对照组用Krebs液持续灌注120 min;缺血再灌注组平衡30 min后全心缺血30 min,再灌注60 min;丹参多酚酸预处理组平衡5 min后加入丹参多酚酸使其在灌流液中终浓度为14μmol/L,持续灌注25 min后全心缺血30 min,再灌注60 min;丹参多酚酸后处理组平衡30 min后全心缺血30 min,加入丹参多酚酸使其在灌流液中终浓度为14μmol/L,再灌注60 min。TTC染色观察心肌梗死面积,并用心肌梗死面积、乳酸脱氢酶(LDH)活性和心脏血流动力学(包括心率、主动脉流量、冠状动脉流量和心输出量)的变化评估大鼠心肌的损伤程度。利用差速离心法提取线粒体,并通过紫外分光光度法测定心肌线粒体Na+,K+-ATP酶和Ca2+-ATP酶的活性。结果:丹参多酚酸预处理组的心肌梗死面积和LDH活性均显著低于缺血再灌注组(24.47±2.14)%比(34.30±2.31)%、(81.46±13.39)U/g比(142.6±6.46)U/g,均P<0.05],缺血再灌注组与后处理组无明显差异。丹参多酚酸对缺血再灌注心肌的血液动力学没有明显作用,只是冠脉流量有较小幅度的增加。丹参多酚酸预处理组线粒体Na+,K+-ATP酶和Ca2+-ATP酶活性显著高于缺血再灌注组(6.12±0.42)U/mg比(4.29±0.28)U/mg、(3.42±0.16)U/mg比(2.62±0.96)U/mg,均P<0.05],而与对照组无明显差异。丹参多酚酸后处理组线粒体Na+,K+-ATP酶和Ca2+-ATP酶活性与缺血再灌注组无统计学差异。结论:丹参多酚酸可以维持心肌线粒体Na+,K+-ATP酶和Ca2+-ATP酶的活性,通过降低缺血再灌注对心肌线粒体的损伤保护心肌。

Effect of salvianolic acid on mitochondrial enzymes in rats with myocardial ischemia

Objective: To investigate the effects of Salvianolic acid on the activity of mitochondrial Na+,K+-ATPase and Ca2+-ATPase in rats with myocardial ischemia-reperfusion.Methods: Forty Wistar rats were used in the Langendorff system and were randomly divided into 4 groups.The hearts in control group were perfused with Krebs buffer for 120 min.For ischemia-reperfusion,the hearts were subjected to global ischemia for 30 min and reperfusion for 60 min.Salvianolic acid pretreatment group was perfused in the presence of 14 μmol/L salvianolic acid ischemia induction.Salvianolic acid post treatment group was perfused in the presence of 14 μmol/L salvianolic acid after ischemia.Tetrazolium chloride(TTC) staining,lactate dehydrogenase(LDH) activity and hemodynamics were used to evaluate tissue injuries.Mitochondria were isolated by differential centrifugation and the activity of Na+,K+-ATPase and Ca2+-ATPase were measured by spectrophotometry.Results: The myocardial infarct size and LDH activity in the salvianolic acid pretreatment group were significantly lower than those in the ischemia-reperfusion group (24.47±2.14)% vs(34.30±2.31)%,(81.46±13.39)U/g vs(142.6±6.46)U/g,both P<0.05].Results of the salvianolic acid post treatment group were not significantly different from those of the ischemia-reperfusion group.Salvianolic acid had no effect on the hemodynamics except for a slight increase in coronary flow.The activities of Na+,K+-ATPase and Ca2+-ATPase of the salvianolic acid pretreatment group,but not of the post treatment group were significantly higher than those of the ischemia-reperfusion group (6.12±0.42)U/mg vs(4.29±0.28)U/mg,(3.42±0.16)U/mg vs(2.62±0.96)U/mg,both P<0.05].Conclusion: Salvianolic acid is cardioprotective for ischemia-reperfusion injury by maintaining the activities of myocardial mitochondrial Na+,K+-ATPase and Ca2+-ATPase and reducing infarct size.