Objective: To observe the effect of electroacupuncture (EA) preconditioning on the expressions of nuclear transcription factors-kappa B (NF-κB) p65, NF-κB inhibitor (IκB) α and IκB kinase (IKK) β in rats with acute myocardial ischemia-reperfusion injury (MIRI) and to explore the mechanism of EA on heart meridian in relieving MIRI.
Methods: A total of 40 SD rats were randomized into a sham-operation group, a model group, an EA heart meridian group and an EA lung meridian group, 10 rats in each one. In the EA heart meridian group, acupuncture was applied to "Shenmen" (HT 7) and "Tongli" (HT 5). In the EA lung meridian group, acupuncture was applied to "Taiyuan" (LU 9) and "Lieque" (LU 7). In these two groups, EA was exerted for 20 min each time, 1 V in voltage and 2 Hz in frequency once a day. A total of 7-day EA stimulation was required before model duplication. In the model group, the EA heart meridian group and the EA lung meridian group, using ligating left anterior descending coronary artery to establish the acute MIRI models. In the sham-operation group, the chest was open, but no ligation was exerted, just the needle was penetrated through the corresponding sites for one time. The electrocardiogram (ECG) was detected and ST segment displacement was analyzed. Using Western blot method, the relative expressions of NF-κB p65, IκBα and IKKβ in myocardial tissue were determined in each group. Using ELISA method, the levels of serum IL-1β and IL-10 were determined in each group.
Results: Compared with the sham-operation group, ST segment displacement value was elevated 30 min after ligating and reperfusion for 120 min in the model group (P<0.05), and the value in the EA heart meridian group was lower than the model group and the EA lung meridian group (P<0.05). Compared with the sham-operation group, the expressions of NF-κB p65 and IKKβ in myocardial tissue were increased (P<0.05) and the expression of IκBα reduced in the rats of the model group (P<0.05). Compared with the model group, the expressions of NF-κB p65 and IKKβ in myocardial tissue were reduced (P<0.05) and the expressions of IκBα increased in the rats of the EA heart meridian group and the EA lung meridian group (P<0.05). Compared with the EA lung meridian group, the expressions of NF-κB p65 and IKKβ in myocardial tissue were reduced (P<0.05) and the expression of IκBα increased in the rats of the EA heart meridian group (P<0.05). Compared with the sham-operation group, the serum level of IL-1β was increased (P<0.05) and IL-10 reduced in the model group (P<0.05). Compared with the model group, the serum level of IL-1β was reduced (P<0.05) and IL-10 increased in the EA heart meridian group and the level of IL-1β was was reduced in the EA lung meridian group (P<0.05). Compared with the EA lung meridian group, the serum level of IL-1β was reduced (P<0.05) and IL-10 increased in the EA heart meridian group (P<0.05).
Conclusion: Electroacupuncture preconditioning at heart meridian acupoints obviously alleviates acute MIRI. IKK/IκB/NF-κB signaling pathway possibly participates in the protective mechanism of electroacupuncture preconditioning on acute MIRI.
目的：观察电针心经腧穴预处理对急性心肌缺血再灌注损伤（MIRI）大鼠核转录因子-κB（NF-κB）p65、NF-κB抑制蛋白（IκB）α、IκB激酶（IKK）β蛋白表达的影响，探讨电针心经腧穴改善心肌缺血再灌注损伤的作用机制。方法：将40只SD大鼠随机分为假手术组、模型组、电针心经组、电针肺经组，每组10只。电针心经组针刺“神门”“通里”，电针肺经组针刺“太渊”“列缺”，两组均采用电针刺激，刺激电压为1 V，频率为2 Hz，每次刺激20 min，每日1次。模型复制前共刺激7 d。模型组、电针心经组、电针肺经组大鼠采用左冠状动脉前降支结扎法复制急性MIRI模型。假手术组开胸后不结扎，仅在相应部位用针空穿1次。检测各组大鼠心电图，分析ST段位移情况；Western blot法检测各组大鼠心肌组织NF-κB p65、IκBα、IKKβ蛋白相对表达量；ELISA法检测各组大鼠血清白细胞介素（IL）-1β及IL-10 含量。结果：与假手术组比较，模型组大鼠结扎后30 min、再灌注120 min的ST段位移值升高（P<0.05），电针心经组低于模型组和电针肺经组（P<0.05）。与假手术组比较，模型组大鼠心肌组织NF-κB p65、IKKβ蛋白表达升高（P<0.05），IκBα蛋白表达降低（P<0.05）；与模型组比较，电针心经组和电针肺经组大鼠心肌组织NF-κB p65、IKKβ蛋白表达均降低（P<0.05），IκBα蛋白表达均升高（P<0.05）；与电针肺经组比较，电针心经组大鼠心肌组织NF-κB p65、IKKβ蛋白表达降低（P<0.05），IκBα蛋白表达升高（P<0.05）。与假手术组比较，模型组大鼠血清IL-1β含量升高、IL-10含量降低（P<0.05）；与模型组比较，电针心经组大鼠血清IL-1β含量降低、IL-10含量升高（P<0.05），电针肺经组大鼠血清IL-1β含量降低（P<0.05）；与电针肺经组比较，电针心经组大鼠血清IL-1β含量降低、IL-10含量升高（P<0.05）。结论：电针心经腧穴预处理可明显减轻大鼠急性心肌缺血再灌注损伤，IKK/IκB/NF-κB信号通路可能参与了电针预处理对心肌缺血再灌注损伤的保护机制。.
Keywords: NF-κB; acute myocardial ischemia-reperfusion injury; electroacupuncture; heart meridian.