腺苷介导循环机械按压内关对心肌缺血大鼠的保护效应

目的  观察循环机械按压内关对心肌缺血大鼠心肌梗死面积和心功能的影响, 初步研究机械因素产生心肌保护效应的机制。方法  18只成年雄性SPF级SD大鼠随机分为假手术组、模型组和机械刺激组, 每组6只。模型组和机械刺激组通过结扎大鼠冠状动脉左前降支建立心肌缺血模型, 假手术组只穿刺心脏不结扎。机械刺激组采用自制仪器按压内关, 按压面为直径3 mm圆形硅胶头, 力度为150 g, 按压方式为按压5 min, 放松5 min, 3次循环为1组, 每天干预1次, 连续3 d。机械刺激3 d后, 三苯基氯化四氮唑(TTC)染色测定心肌梗死面积; 超声心动图测定左室射血分数(LVEF); Western blot法检测大鼠心肌中炎症因子白介素-1β(IL-1β)、白介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)的表达; ELISA法检测血清腺苷的浓度; 免疫组化法检测穴区腺苷脱氨酶(ADA)的表达水平。结果  与假手术组比, 模型组大鼠心肌梗死面积增加(P < 0.001), LVEF值下降(P < 0.001), 血清中腺苷含量和穴区ADA的表达没有差异(P>0.05);与模型组比较, 机械刺激组大鼠心肌梗死面积减少(P < 0.01), LVEF值增加(P < 0.001), 心肌中炎症因子IL-1β、IL-6和TNF-α的表达显著降低(P < 0.000 1), 血清中腺苷含量增加(P < 0.01), 穴区腺苷脱氨酶表达水平减少(P < 0.05)。结论  循环机械按压内关穴可减少心肌缺血损伤大鼠的梗死面积, 改善心功能; 其机制或与机械刺激抑制穴区ADA表达, 限制腺苷降解, 进而提高动脉中的腺苷浓度有关。 

Adenosine-Mediated Cardioprotection of Local Cyclical Compression on Neiguan on Myocardial Ischemic Rats

OBJECTIVE  To observe the effect of cyclic mechanical compression of Neiguan (PC 6) on myocardial infarct size and cardiac function in rats with myocardial ischemia, and to preliminarily investigate the possible mechanism by which this factor produces cardioprotective effects.METHODS  A total of 18 adult male SD rats were randomly divided into sham, model, and mechanical stimuli group, 6 rats in each group. The myocardial ischemia model was established by ligating the left anterior descending (LAD) branch of the coronary artery in the model and mechanical stimuli group, while threading but not ligating at LAD was applied in the sham group. In the mechanical stimuli group, the Neiguan (PC 6) was pressed by the self-made instrument, with a contact surface of 3 mm diameter circular silica gel head and a force of 150 g, and the pressing mode was 5 min of pressing and 5 min of relaxation, with 3 cycles as one group, with intervention once a day for 3 consecutive days. The TTC staining was used to measure myocardial infarction area. Left ventricular ejection fraction(LVEF)was measured by echocardiography. The myocardial expression of IL-1β, IL-6 and TNF-α were detected by Western blot. Serum adenosine concentration was detected by ELISA. The expression level of adenosine deaminase(ADA)in acupoints was detected by immunohistochemistry.RESULTS  Compared with sham group, myocardial infarction area of model group increased(P < 0.001), LVEF value decreased(P < 0.001), and there was no difference in serum adenosine content and ADA expression in acupoint area (P>0.05). Compared with model group, the myocardial infarction area and myocardial expression of IL-1β, IL-6 and TNF-α in mechanical stimuli group decreased (P < 0.01), LVEF value increased (P < 0.001), serum adenosine content increased (P < 0.01), and the expression level of adenosine deaminase in acupoints decreased (P < 0.05).CONCLUSION  Cyclic mechanical compression of Neiguan (PC 6) can reduce the infarct size and improve cardiac function in Myocardial ischemic rats. The mechanism may be related to mechanical stimuli limiting adenosine degradation by inhibiting the expression of ADA in acupoint, contributing to cardioprotection via increased adenosine concentration in the artery.