Mechanistic study of electroacupuncture combined with exercise preconditioning in modulating AMPK-mediated inflammatory injury to protect myocardium in rats with myocardial ischemia-reperfusion injury

Wang Zhihao; Wang Lei; Zhu Luwen; Li Hongyu; Guo Wang; Zhang Xuanning; Tang Qiang

doi:10.11986/j.issn.1673-873X.2025.02.11

Abstract：Objective To investigate the protective effects of electroacupuncture(EA)combined with exercise preconditioning(EP)on myocardial ischemia-reperfusion injury(MIRI)in rats,focusing on the role of AMP-activated protein kinase(AMPK)-mediated inflammatory damage.Methods Sixty male Sprague-Dawley rats were randomly assigned to five groups(n=12 each)using a random number table:Control(Con),I/R model(I/R),I/R+EA+EP,I/R+Compound C(AMPK inhibitor),and I/R+EA+EP+Compound C.Preconditioning groups received three weeks of EA combined with exercise ac-cording to their group assignment.Except for the Con group,all rats then underwent MIRI via Langendorff isolated heart per-fusion.Compound C(dosoxmorphin)was administered intraperitoneally for 1-2 h before modeling in the I/R+Compound C and I/R+EA+EP+Compound C groups.Cardiac function indices were recorded using a MedLab bio-signal acquisition sys-tem.Myocardial pathology was examined by hematoxylin-eosin staining.Levels of tumor necrosis factor-α(TNF-α)and inter-leukin-6(IL-6)in heart tissue were measured by ELISA.Transmission electron microscopy was used to assess ultrastructural changes in cardiomyocytes.Western blotting quantified myocardial expression of AMPK,phosphorylated AMPK(p-AMPK),silent information regulator 1(SIRT1),nuclear factor-KB(NF-κB),and phosphorylated NF-κB(p-NF-κB).Results Before ischemia,there were no significant differences in coronary flow(CF),heart rate(HR),left ventricular developed pressure(LVDP),maximum rate of increase of left ventricular pressure(+dp/dtmax)and maximum rate of decrease of left ventricular pressure(-dp/dtmax)(P＞0.05).After 120 min of reperfusion,the levels of all cardiac function parameters in the I/R group were significantly lower than those in the Con group(P＜0.05);the levels of all cardiac function parameters in the I/R+EA+EP group were significantly higher than those in the I/R group(P＜0.05);the levels of all cardiac function parameters in the I/R+Compound C group were significantly lower than those in the I/R and I/R+EA+EP groups(P＜0.05).The levels of all cardiac function parameters in the I/R+EA+EP+Compound C group were significantly lower than those in the Con group and I/R+EA+EP group(P＜0.05).The levels of HR and-dp/dtmax in the I/R+EA+EP+Compound C group were signifi-cantly higher than those in the I/R+Compound C group(P＜0.05).HE staining showed that the degree of myocardial patho-logical injury in the I/R+EA+EP group was alleviated compared with the I/R group,and the degree of myocardial pathologi-cal injury in the I/R+EA+EP+Compound C group was alleviated compared with the I/R+Compound C group.The results of ELISA showed that the expression levels of TNF-α and IL-6 in the myocardial tissue of rats in the I/R+EA+EP group were lower than those in the I/R group,and the expression levels of TNF-α and IL-6 in the I/R+EA+EP+Compound C group were lower than those in the I/R+Compound C group,and the differences were statistically significant(P＜0.05).Trans-mission electron microscopy showed that the ultrastructural damage of myocardial cells in the I/R+EA+EP group was allevia-ted compared with the I/R group,and the ultrastructural damage of myocardial cells in the I/R+EA+EP+Compound C group was alleviated compared with I/R+Compound C group.Western blot results showed that the p-AMPK/AMPK ratio and the relative expression of SIRT1 protein in the myocardial tissue of rats in the I/R+EA+EP group were significantly up-regulated and the p-NF-κB/NF-κB ratio was significantly down-regulated compared with those in the I/R group(P＜0.05);the p-AMPK/AMPK ratio and the relative expression of SIRT1 protein in the myocardial tissue of rats in the I/R+EA+EP+Compound C group were significantly up-regulated compared with those in the I/R+Compound C group,and the p-NF-κB/NF-κB ratio was down-regulated compared with that in the I/R+Compound C group(P＜0.05).Conclusion Electroacupuncture combined with exercise preconditioning markedly attenuates inflammatory injury in myocardium of rats with MIRI,likely via modulation of the AMPK/SIRT1/NF-κB signaling pathway.