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

Abstract

To observe the effects of electroacupuncture (EA) on inflammatory reaction of acute myocardial ischemia (MI) in mice, and to explore its action mechanism. Forty adult male C57BL/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). 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). 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.