Objective: To observe the effect of electroacupuncture (EA) at "Neiguan" (PC 6) on cardiac function and cardiomyocyte apoptosis in rats with acute myocardial ischemia (AMI), and to explore the correlation between myocardial protective effect of EA and inflammatory factors i.e. interleukin-1β (IL-1β) and interleukin-17 (IL-17) of "Neiguan" (PC 6) area.
Methods: A total of 40 male SD rats with normal ultrasonic cardiogram were randomized into a sham-operation group, a sham-operation plus EA group, a model group and an EA group, 10 rats in each group. The AMI model was established by ligating the left anterior descending (LAD) branch of the coronary artery in the model group and the EA group, while the threading without ligating was adopted in the sham-operation group and the sham-operation plus EA group. In the sham-operation plus EA group and the EA group, EA at bilateral "Neiguan" (PC 6) was applied, with disperse-dense wave, 2 Hz/100 Hz in frequency and 2 mA in density, once a day, 20 min a time for 3 days. The cardiac ejection fraction (EF) and fractional shortening (FS) were measured by ultrasonic cardiogram to evaluate the cardiac function, the cardiomyocyte apoptosis was detected by TUNEL staining, the infiltration of inflammatory factors of "Neiguan" (PC 6) area was observed by H.E. staining, the expression of inflammatory factors IL-1β and IL-17 of "Neiguan" (PC 6) area was detected by immunofluorescence staining.
Results: Compared with the sham-operation group, EF and FS were decreased (P<0.001), the average optical density of cardiomyocyte apoptosis was increased (P<0.001), the infiltration of inflammatory factors was obvious in skin dermis of "Neiguan" (PC 6) area in the model group; the positive expression of IL-1β and IL-17 of "Neiguan" (PC 6) area was increased in the model group and the sham-operation plus EA group (P<0.001, P<0.01). Compared with the model group, EF and FS were increased (P<0.01), the average optical density of cardiomyocyte apoptosis was decreased (P<0.01), the infiltration of inflammatory factors was aggravating in skin dermis of "Neiguan" (PC 6) area, and the positive expression of IL-1β and IL-17 of "Neiguan" (PC 6) area was increased in the EA group (P<0.001, P<0.01).
Conclusion: Electroacupuncture at "Neiguan" (PC 6) can improve the cardiac function and reduce the apoptosis of cardiomyocyte in rats with acute myocardial ischemia, its mechanism may be related to the regulation of the inflammatory factors of "Neiguan" (PC 6) area.
目的：观察电针“内关”穴对急性心肌缺血（AMI）大鼠心功能和心肌细胞凋亡的影响，探讨电针促心肌保护效应与“内关”穴区炎性因子白细胞介素-1β（IL-1β）、白细胞介素-17（IL-17）的相关性。方法：将超声心动图正常的40只雄性SD大鼠随机分为假手术组、假手术电针组、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（LAD）结扎法制备AMI模型，假手术组和假手术电针组仅穿线不结扎。假手术电针组和电针组在双侧“内关”穴进行电针（疏密波，2 Hz/100 Hz，2 mA）治疗，每天1次，每次20 min，治疗3 d。采用超声心动图测算大鼠心脏射血分数（EF）和短轴缩短指数（FS）以评价心功能；TUNEL染色法检测大鼠心肌细胞凋亡情况；HE染色法观察大鼠“内关”穴区炎性因子浸润情况；免疫荧光染色法检测大鼠“内关”穴区局部炎性因子IL-1β、IL-17的表达。结果：与假手术组比较，模型组大鼠EF和FS均降低（P<0.001）、心肌细胞凋亡平均吸光度值增加（P<0.001）、“内关”穴皮肤真皮层炎性细胞浸润明显，模型组与假手术电针组穴区局部IL-1β和IL-17的阳性表达均增强（P<0.001，P<0.01）；与模型组比较，电针组大鼠EF和FS均升高（P<0.01），心肌细胞凋亡平均吸光度值降低（P<0.01），“内关”穴皮肤真皮层炎性细胞浸润加剧，穴区局部IL-1β和IL-17的阳性表达均增强（P<0.001，P<0.01）。结论：电针“内关”穴能够改善急性心肌缺血大鼠的心功能，减少心肌细胞凋亡，可能与调节“内关”穴区炎性因子有关。.
Keywords: Point PC 6 (Neiguan); acute myocardial ischemia; cardiac function; electroacupuncture; inflammatory response.