线粒体通透性转换孔对红景天苷减轻心肌缺血再灌注损伤的作用

Effect of mitochondrial permeablity transition pore on cardio-protection of salidroside against ischemia reperfusion injury

目的探讨线粒体通透性转换孔(mPTP)在红景天苷减轻大鼠心肌缺血再灌注损伤(MIRI)中的作用和机制。方法使用Langendorff装置建立大鼠离体心脏缺血/再灌注损伤模型。将60只SPF级健康雄性成年SD大鼠随机分为假手术组(Sham组)、缺血/再灌注组(I/R组)、红景天苷组(Sal组)和环孢菌素A组(CsA组)。用Western Blot法检测细胞色素C(Cyt-c)分别在细胞浆和线粒体中的表达情况;用免疫组化法检测活化型半胱天冬酶-9(cleaved caspase-9)和活化型半胱天冬酶-3(cleaved caspase-3)在各组心肌组织的表达水平;用线粒体肿胀实验法评估各组心肌的mPTP开放程度;酶联免疫分析(Elisa)法测定各组大鼠心肌组织中线粒体细胞色素C氧化酶(COX)和琥珀酸脱氢酶(SDH)的活性。结果与Sham组比较,I/R组心肌组织中大量Cyt-c由线粒体释放到细胞浆中,cleaved caspase-9和cleaved caspase-3的表达水平均显著上升,线粒体吸光度下降率明显升高,COX和SDH活性降低(P<0.05);与I/R组比较,Sal组和CsA组Cyt-c释放和线粒体吸光度下降均受抑制,cleaved caspase-9和cleaved caspase-3的表达水平均下降,COX和SDH活性均升高(P<0.05)。结论红景天苷可通过抑制mPTP开放、保护线粒体功能来发挥心肌保护作用,其具体机制与减少Cyt-c的释放、抑制caspase-9和caspase-3的激活及提高COX和SDH的活性有关。

Objective To study the effect of mitochondrial permeablity transition pore(mPTP)on cardio-protection of salidroside against ischemia reperfusion injury.Methods The device of Langendorff was used to establish the isolated rat heart ischemia reperfusion model.60 SD male rats of SPF grade were divided into Sham group,I/R group,Sal group and CsA group.Western Blot analysis was used to determine the expression of Cyt-c in cytoplasm and mitochondria respectively.Immunohistochemistry was used to detect the expression levels of cleaved caspase-9 and cleaved caspase-3.Mitochondrial swelling experiment was used to estimate the degree of mPTP opening.Elisa was used to determine the activity of COX and SDH.Results Compared with the Sham group,I/R can induce the release of Cyt-c from the mitochondria,increase the expression level of cleaved caspase-9 and cleaved caspase-3,increase the extent of mitochondrial swelling and reduce the activity of COX and SDH(P<0.05).Compared with I/R group,the Cyt-c release and mitochondrial absorbance decrease in Sal group and CsA group were both inhibited,the expression levels of cleaved caspase-9 and cleaved caspase-3 were decreased,and COX and SDH activities are alleviated(P<0.05).Conclusion Salidroside can inhibit the myocardial ischemia reperfusion injury by inhibiting mPTP opening and protecting mitochondrial function.The specific mechanism is related to reducing the release of Cyt-c,inhibiting the activation of caspase-9 and caspase-3,and increasing the activity of COX and SDH.