克罗卡林及优降糖对实验性急性心肌梗死的影响

Effect of cromakalim and glibenclamide on infarct size and ATP content of myocardium in experimental rat model of acute myocardial infarction

目的 :研究克罗卡林及优降糖对心肌梗死面积及梗死部位心肌细胞三磷酸腺苷 (ATP)含量的影响。方法 :以 Wistar大鼠为模型 ,开胸安置缺血再灌注装置 ,将大鼠分为 4组 :A组未作特殊处理 ;B组阻断冠状动脉 (冠脉 ) 1小时 ,再灌注 2小时 ;C组冠脉阻断前 0 .5小时静注克罗卡林 1 0 0μg/ kg;D组冠脉阻断前 0 .5小时静注克罗卡林 1 0 0μg/ kg,接着予优降糖 0 .3mg/ kg。各组动物经上述处理后 ,抽股静脉血测肌酸激酶浓度 ,随后 B、C、D组各分成 2个亚组 ,一亚组摘取心脏测梗死面积 ,另一亚组测梗死部位心肌 ATP含量。结果 :缺血后血浆肌酸激酶含量升高 ,局部 ATP浓度下降 ;克罗卡林缩小心肌梗死面积 ,降低血浆肌酸激酶浓度 ,减轻梗死部位心肌细胞 ATP的消耗 (C组与 B组比较 ,各指标 P值均 <0 .0 1 ) ;优降糖对克罗卡林的上述效应有拮抗作用。结论 :克罗卡林对缺血心肌有明显的保护作用 ;其机制可能与激活心肌细胞膜 ATP敏感性钾通道有关 ;优降糖对克罗卡林的上述效应有拮抗作用。

Objective:To study the effect of cromakalim and glibenclamide on infarct size and ATP content of myocardium in rats exposed to ischemiareperfusion (I/R).Methods:The snare for occlusion and reperfusion was blaced to the main coronary artery in 84 Wistar rats which were divided into 4 groups:control,I/R, I/R+ cromakalim and I/R+ cromakalim+glibenclamide.Animals in each group sustained ischemia for 1 hour followed by 2 hours of reperfusion.The plasma concentration of creatine kinase and the tissue ATP content of myocardium were assayed and the infarct size of myocardium was measured.Results:The protective effect of cromakalim was evident.The infarct size and the plasma concentration of CK were lower while the tissue content of ATP was much higher than those of I/R group ( P <0 01).Glibenclamide reduced the effect of cromakalim ( P <0 01).Conclusions:Cromakalim protects the myocardium against I/R damage,the possible mechanism of which is related to the activation of the ATPsensitive potassium channel of myocardial membrane.