白藜芦醇预处理对糖尿病大鼠心肌缺血再灌注损伤中Cx43的作用

Effect of resveratrol pretreatment on Cx43 in myocardial ischemia reperfusion injury in diabetic rats

目的探讨白藜芦醇预处理对糖尿病大鼠心肌缺血再灌注损伤中缝隙连接蛋白43(Cx43)的影响。方法清洁级健康成年雄性SD大鼠,体重200~220 g。采用腹腔注射1%链脲佐菌素柠檬酸缓冲液30 mg/kg制备大鼠糖尿病模型。取糖尿病大鼠采用随机数字表法分为3组(n=10):糖尿病鼠假手术组(Sham组),糖尿病鼠心肌缺血再灌注组(MIR组),白藜芦醇-糖尿病鼠心肌缺血再灌注组(MIR+Res组)。取正常大鼠10只作为白藜芦醇-非糖尿病鼠心肌缺血再灌注组(N+Res组)。采用结扎冠状动脉左前降支30 min,恢复灌注120 min的方法制备大鼠心肌缺血再灌注损伤模型。N+Res、MIR+Res组于缺血再灌注模型建立前5d腹腔注射生理盐水稀释的白藜芦醇15 mg/kg,Sham、MIR组不注射白藜芦醇,注射等量生理盐水。于再灌注120min时腹主动脉取血检测LDH、CK-MB,TNF-α,IL-6浓度。取心脏组织检测MDA,SOD含量,切片HE染色观察病理改变,Western blot检测心肌组织里Cx43蛋白表达水平。结果 Sham组心肌细胞肌原纤维排列整齐,胞浆内线粒体丰富,部分组织见炎症细胞浸润。MIR组心肌组织结构紊乱,心肌肌原纤维溶解,大量炎症细胞浸润。N+Res、MIR+Res组心肌结构紊乱及细胞水肿程度较MIR组明显减轻,可见少量炎性细胞浸润。其中,N+Res组病理学损伤较MIR+Res组轻。与MIR组比较,N+Res及MIR+Res组的CK-MB、LDH、TNF-α、IL-6等炎性指标浓度降低(P <0.05);MDA含量降低,SOD含量增高、Cx43表达上升(P <0.05)。结论白藜芦醇通过作用于Cx43,减轻了糖尿病心肌缺血再灌注损伤,起到了心肌保护作用。

Objective To investigate the effect of resveratrol pretreatment on connexin43(Cx43)in myocardial ischemia reperfusion injury of diabetic rats. Methods Clean healthy adult male SD rats weighed 200~220 g. Rat diabetes model was prepared by intraperitoneal injection of 1% streptozotocin citric acid buffer at 30 mg/kg. Diabetic rats were divided into 3 groups(n = 10 each)using a random number table, the Sham operation group(group Sham), the myocardial ischemia reperfusion group(group MIR) and the resveratrol-diabetic myocardial ischemia reperfusion group(MIR+Res group). Ten normal rats were selected as the resveratrolnon-diabetic rat myocardial ischemia reperfusion group(N+Res group). The model of myocardial ischemia reperfusion injury in rats was prepared by ligating the left anterior descending branch of coronary artery for 30 minutes and restoring perfusion for 120 minutes.In the N+Res and MIR+Res groups, 15 mg/kg of resveratrol diluted with normal saline was injected intraperitoneally 5 days before the establishment of ischemia reperfusion model, while in Sham and MIR groups, resveratrol was not injected, and equivalent saline was injected. LDH, CK-MB, TNF-α and IL-6 concentrations were detected by abdominal aorta blood sampling at 120 minutes after reperfusion, and the heart tissue was taken. The contents of MDA and SOD were detected. The pathological changes were observed by HE staining of sections. Results Myofibrils of myocardial cells in group Sham were orderly arranged with abundant mitochondria in the cytoplasm, and inflammatory cells infiltrated some tissues. The myocardial tissue structure of group MIR was disordered, myocardial myofibrils were dissolved, and a large number of inflammatory cells were infiltrated. Myocardial structural disorder and cell edema degree in the N+Res and MIR+Res groups were significantly reduced compared with those in the group MIR, and a small amount of inflammatory cell infiltration was observed. Among them, pathological damage in the group N+Res was less than that in the group MIR+ Res. Compared with the group MIR, the concentrations of CK-MB, LDH, TNF-α, IL-6 and other inflammatory indicators in the N+Res and MIR+ Res groups were decreased(P < 0.05). MDA content decreased, SOD content increased and Cx43 expression increased(P < 0.05).Conclusion By acting on Cx43, resveratrol can alleviate the myocardial ischemia reperfusion injury of diabetes and protect the myocardium.