益气活血中药联合缺血后适应保护缺血再灌注大鼠心肌损伤的机制

目的：观察益气活血中药是否可增加缺血后适应（ischemic postconditioning,IPoC）保护缺血再灌注（ischemiareperfusion,I/R）大鼠心肌的作用,并探讨其可能的作用机制。方法：SD大鼠75只,随机分为假手术组（冠状动脉前降支下置线不结扎,n=15）,I/R组（冠状动脉前降支结扎30 min,再灌注1 h,n=15）,IPoC组（冠状动脉前降支结扎30 min,3次10 s的再灌注/缺血循环,再持续灌注1 h,n=15）,益气活血加IPoC组（心悦胶囊0.162 g/kg加芎芍胶囊0.135 g/kg,连续灌胃14 d,末次灌胃后2 h实施IPoC干预,n=15）,福辛普利钠加IPoC组（福辛普利钠片0.9 mg/kg灌胃,n=15）。比色法测定血清肌酸激酶同工酶（creatine kinase-MB,CK-MB）和肌钙蛋白T（cardiac troponin T,cTnT）的含量,氯化硝基四氮唑蓝染色检测大鼠左室心肌梗死面积,免疫组织化学法检测心肌组织Toll样受体（Toll-likereceptor,TLR）2、4的表达,酶联免疫吸附测定法检测心肌组织白细胞介素1β（interleukin-1β,IL-1β）和白细胞介素6（interleukin-6,IL-6）的含量。结果：与I/R组比较,IPoC组大鼠血清CK-MB活性和cTnT水平明显降低（P〈0.01）,心肌梗死面积显著减小（P〈0.01）,心肌组织TLR2、4表达和炎症因子IL-6、IL-1β含量明显下降（P〈0.05,P〈0.01）;与福辛普利钠加IPoC组比较,益气活血加IPoC组心肌组织TLR2、4表达显著降低（P〈0.05,P〈0.01）;与IPoC比较,益气活血加IPoC可进一步减小I/R大鼠心肌梗死面积,降低血清CK-MB活性（P〈0.01）,减少心肌TLR2、4表达和IL-1β、IL-6含量（P〈0.05,P〈0.01）。结论：益气活血中药可加强缺血后适应对I/R大鼠心肌的保护作用,其机制可能与抑制TLR2、4以及其下游促炎性细胞因子的表达有关。

Mechanisms of Chinese herbs combined with ischemic postconditioning in protecting myocardium of rats from ischemia-reperfusion injury

Objective：To observe the effects of Chinese patent medicines with the function of replenishing qi to activate blood（RQAB） plus ischemic postconditioning（IPoC） in protecting myocardium of rats from ischemiareperfusion （l/R） injury,and to explore the possible mechanisms. Methods：Seventy-five Sprague-Dawiey rats were randomly divided into sham-operated group（the suture was penetrated around the left anterior descending coronary artery,but not tied,n=15）,l/R group（30 minutes of in situ transient occlusion of the left anterior descending artery,followed by 1 hour of reperfusion,n=15）, IPoC group（30 minutes occlusion of the left anterior descending artery,followed by 3 cycles of 10 s of reperfusion/10 s of ischemia before 1-hour reperfusion,n=15）,RQAB plus IPoC group（pretreated with 0.162 g/kg Xinyue Capsule and 0.135 g/kg Xiongshao Capsule for 14 days,and treated with IPoC 2 h after the final gavage,n=15）,fosinopril sodium plus IPoC group（pretreated with fosinopril sodium,0.9 mg/kg, n=15）.Serum creatine kinase-MB（CK-MB） activity and cardiac troponin T（cTnT） level were detected; myocardial infarction size was measured by nitrotetrazolium blue chloride staining;Toll-like receptor 2（TLR2） and TLR4 in myocardial tissue were examined by immunohistochemical method;interleukin-1β（IL-1β） and interleukin-6（IL-6） levels in myocardial tissue were examined by enzyme-linked immunosorbant assay. Results：Compared with the l/R group,myocardial enzymes and infarction size were decreased significantly in the IPoC group（P〈0.01）;expressions of TLR2 and TLR4 and levels of IL-1βand IL-6 in myocardial tissues were also significantly lower than those in the l/R group（P〈0.05）.Compared with the fosinopril sodium plus IPoC group,expressions of TLR2 and TLR4 were decreased significantly in the RQAB plus IPoC group（P〈0.05,P〈0.01）.Compared with IPoC,RQAB plus IPoC reduced the infarction size and the release of myocardial enzyme CK-MB（P〈0.01）,and decreased the expressions of TLR2 and TLR4 and the levels of IL-1βand IL-6（P〈0.05,P〈0.01） in myocardial tissues. Conclusion：Pretreatment with Chinese herbs for nourishing qi and activating blood circulation can enhance the protective effect of IPoC on rat myocardial l/R injury,and its mechanism may be related to inhibition of TLR expression and expressions of the downstream proinflammatory cytokines.