ERK抑制剂对心肺复苏后大鼠心肌缺血再灌注损伤和能量代谢的作用研究

Effects of ERK inhibitor on myocardial ischemia reperfusion injury and energy metabolism dysfunction in rats after cardiopulmonary resuscitation

目的探讨ERK抑制剂PD98059对于心脏骤停/心肺复苏(CA/CPR)后大鼠心肌能量代谢和心肌缺血再灌注损伤的作用。方法 36只大鼠按随机数字表法分为假手术(Sham)组(n=6)、模型(CA)组(n=15)和PD98059(PD)组(n=15)。Sham组只单纯行手术操作;CA组和PD组经食道交流电刺激诱导心室颤动(VF)建立大鼠CA/CPR模型,恢复自主循环(ROSC)后,PD组立即静脉注射PD98059(0.3 mg/kg),CA组立即静脉注射等量生理盐水。观察复苏后24 h存活情况,采集血清检测心肌肌钙蛋白I,同时取心肌组织进行HE染色、ATP含量测定,并采用蛋白免疫印迹法检测磷酸化ERK(p-ERK)的表达水平。结果复苏后24 h,各组存活情况为Sham组6只、CA组6只、PD组13只。与Sham组比较,CA和PD组血清心肌肌钙蛋白I水平升高;PD组血清心肌肌钙蛋白I水平较CA组下降(P<0.05)。PD组ATP含量较CA组明显升高(P<0.05),心肌病理损伤程度也较CA组明显减轻。与Sham组比较,CA和PD组大鼠心肌组织p-ERK的表达水平升高;PD组p-ERK表达水平较CA组下降(P<0.05)。结论 ERK抑制剂PD98059治疗能够改善心肺复苏后心肌能量代谢障碍,减轻心肌缺血再灌注损伤。

Objective To investigate the effects of ERK inhibitor PD98059 on cardiac energy metabolism and myocardial ischemia reperfusion injury in rats after cardiac arrest/cardiopulmonary resuscitation(CA/CPR).Methods Thirty-six rats were randomly divided into three groups:Sham group(n=6),PD98059(PD)group(n=15)and model(CA)group(n=15).Rat model of CA/CPR in PD and CA groups was established by induction of ventricular fibrillation(VF)by electrical stimulation of the esophagus.Sham group was given operation only.After the restoration of spontaneous circulation(ROSC),PD group was given intravenous injection of PD98059(0.3 mg/kg)immediately,CA group was given the same amount of normal saline.Survival was observed for 24 h.Serum samples were collected 24 h after resuscitation to detect troponin I.Meanwhile,myocardial tissue samples were collected for hematoxylin-eosin(HE)staining and ATP content determination.Western blot assay was used to detect the level of ERK and phosphorylation of ERK(p-ERK).Results After 24 h,the survival was 6 for Sham group,6 for CA group and 13 for PD group.The serum level of troponin I was increased in CA and PD groups than that of Sham group,and which was decreased in PD group than that of CA group(P<0.05).The cardiac tissue ATP content was significantly higher in PD group than that of CA group(P<0.05),and the degree of myocardial pathological injury was significantly less in PD group than that of CA group.Compared with Sham group,the expression of myocardial p-ERK was significantly increased in CA and PD groups.The expression of myocardial p-ERK was significantly decreased in PD group than that of CA group(P<0.05).Conclusion The treatment with ERK inhibitor PD98059 can improve the myocardial energy metabolism dysfunction and alleviate the myocardial ischemia reperfusion injury after cardiopulmonary resuscitation.