电针对急性心肌缺血模型小鼠心肌组织中炎性反应的影响

Effects of electroacupuncture on inflammatory response of cardiac muscle tissue in mice with acute myocardial ischemia

目的:观察电针对小鼠急性心肌缺血损伤中炎性反应的影响,探讨其作用机制。方法:将40只成年雄性C57BL/6小鼠随机分为对照组、假手术组、模型组和电针组,每组10只。模型组和电针组采用冠状动脉左前降支结扎法建立心肌缺血模型。电针组电针"内关"穴,刺激强度2 mA,疏密波,频率2 Hz/100 Hz,每次30 min,每天1次,共治疗5 d;对照组与模型组仅抓取、固定,不予电针刺激;假手术组未进行冠状动脉左前降支结扎,余步骤同模型组。记录Ⅱ导联心电图并计算△ST值评价模型,采用TTC、HE染色分别评价小鼠心肌组织梗死面积和病理变化,Western blot检测缺血心肌组织肿瘤坏死因子α(TNF-α)、核转录因子-κB p65(NF-κB p65)、白介素-1β(IL-1β)、白介素-8(IL-8)蛋白表达水平。结果:与假手术组相比,造模后模型组和电针组S-T段抬高明显(均P<0.01),提示模型成功建立;TTC、HE染色结果显示,与假手术组比,模型组心肌梗死面积显著增加(P<0.01),出现明显的心肌纤维损伤和炎性浸润,与模型组相比,电针组心肌梗死面积明显减小(P<0.01),心肌纤维损伤和炎性浸润明显改善;与对照组相比,假手术组各蛋白表达水平差异无统计学意义(均P>0.05),与假手术组比,模型组TNF-α、NF-κB p65、IL-1β、IL-8的蛋白水平明显升高(P<0.01,P<0.05),与模型组相比,电针组心肌组织TNF-α、NF-κB p65、IL-1β、IL-8蛋白表达水平均显著降低(均P<0.01)。结论:电针可能通过降低心肌缺血小鼠心肌组织TNF-α、NF-κB p65、IL-1β、IL-8蛋白表达水平,抑制炎性反应,实现心肌保护效应。

Objective To observe the effects of electroacupuncture（EA） on inflammatory reaction of acute myocardial ischemia（MI） in mice, and to explore its action mechanism. Methods Forty adult male C57 BL/6 mice were randomly divided into a control group, a sham operation group, a model group and an EA group, 10 mice in each one. The model was established in the model group and EA group by ligating the left anterior descending branch of coronary artery. The mice in the EA group were treated with EA at ＂Neiguan＂（PC 6） with 2 mA of intensity and 2 Hz/100 Hz of frequency; EA was given 30 min per treatment, once a day for totally 5 days. The mice in the control group and model group were treated with immobilization and no EA was given. The mice in the sham operation group were not treated with ligating at the left anterior descending branch of coronary artery, but the remaining procedure was identical to the model group. The electrocardiogram was recorded and △ST was calculated to evaluate the model. TTC and HE staining methods were applied to evaluate the infarct size and pathologic change of myocardial tissue, respectively. Western blot method was applied to test the protein expression levels of tumor necrosis factor-α（TNF-α）, nuclear factor-κB p65（NF-κB p65）, interleukin-1β（IL-1β） and interleukin-8（IL-8）. Results Compared with the sham operation group, the S-T segments in the model group and EA group were increased obviously after modeling（both P〈0.01）, indicating the MI model was established successfully. The TTC and HE staining results indicated, compared with the sham operation group, the model group had larger infarction size（P〈0.01）, more myocardial fibers injury and inflammatory infiltration; compared with the model group, the infarction size of the EA group was significantly reduced（P〈0.01）, and the myocardial fibers injury and inflammatory infiltration were improved. Compared with the control group, the protein expression levels in the sham operation group were similar（all P〈0.05）; compared with the sham operation group, the expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 were significantly increased in the model group（P〈0.01, P〉0.05）; compared with the model group, the expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 were significantly reduced in the EA group（all P〈0.05）. Conclusion EA might reduce the protein expression levels of TNF-α,NF-κB p65, IL-1β and IL-8 in cardiac muscle tissue to inhibit inflammatory reaction and achieve myocardial protective effect in mice with acute myocardial ischemia.