Objective: To observe the effects of electroacupuncture (EA) pretreatment on the cardiac ejection fraction (EF), the number of macrophages in spleen and heart, and the expression of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and interleukin-1β (IL-1β) in myocardium in mice with acute myocardial ischemia, and to explore the possible mechanism of EA pretreatment on promoting myocardial protection.
Methods: A total of 30 male C57BL/6J mice were randomly divided into a control group, a model group and an EA pretreatment group, 10 rats in each group. The acute myocardial ischemia model was established by ligating the left anterior descending branch of the coronary artery in the model group and EA pretreatment group, while threading but no ligating at left anterior descending branch of the coronary artery was applied in the control group. In the EA pretreatment group, mice were intervented with EA at bilateral "Neiguan" (PC 6), disperse-dense wave, frequency of 2 Hz/15 Hz, intensity of 2 mA; each EA treatment last for 20 min, once a day, and 3-day treatment was given before model establishment. The EF value was evaluated by ultrasonic cardiogram; the number of macrophages in spleen and heart was measured by flow cytometry; the expression level of NLRP3 and IL-1β in myocardium was measured by Western blot.
Results: Compared with the control group, the EF value was decreased in the model group (P<0.001), the number of macrophages in the heart and spleen was increased (P<0.001), and the expression level of NLRP3 and IL-1β in the myocardium was increased (P<0.001, P<0.01). Compared with the model group, the EF value was increased in the EA pretreatment group (P<0.01), the number of macrophages in the heart and spleen was decreased (P<0.01), and the expression level of NLRP3 and IL-1β in the myocardium was decreased (P<0.01, P<0.05).
Conclusion: EA pretreatment could reduce the number of macrophages in spleen and heart, down-regulate the expression of NLRP3 and IL-1β in myocardial tissue in mice with acute myocardial ischemia, which could relieve the local inflammatory response and achieve the myocardial protective effect.
Keywords: acute myocardial ischemia; ejection fraction (EF); electroacupuncture; interleukin-1β (IL-1β); macrophage; nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3); pretreatment.