ObjectiveTo explore the effects of electroacupuncture pretreatment on mitochondrial energy metabolism in the rats with myocardial ischemia reperfusion injury (MIRI). MethodsA total of 60 SPF Wistar rats were randomly divided into a sham-operation group (sham group), a myocardial ischemia reperfusion injury group (MIRI group) and an electroacupuncture pretreatment group (EA group), 20 rats in each one. The rats in the sham group and the MIRI group were binded for 7 days, once a day, 20 min each time. On the 8th day, the sample was collected after the heart exposed for 50 min in thoractomy in the sham group and the sample was collected after ischemia for 20 min and reperfusion for 30 min in thoractomy in the MIRI group. In the EA group, the pretreatment intervention with electroacupuncture was applied at "Nèiguān (内关PC6)", "Guānyuán (关元CV4)" and "Zúsānlĭ (足三里ST36)" in the rats for 7 days, once a day, 20 min each time. On the 8th day, after ischemia for 20 min and reperfusion for 30 min in thoractomy, the sample was collected in the EA group. The changes in STⅡ segment of electroacardiogram (ECG) were observed and measured. Using enzyme-linked immunosorbent assay (ELISA), the concentrations of cardiac troponin T (cTnT) and cardiac troponin I (cTnI)were detected. Using nitro blue tetrazolium chloride monohydrate (NBT) staining, the myocardial infarction weight percentage was measured. Using ELISA, the concentrations of mitochondrial adenosine monophosphate (AMP), adenosine diphosphate (ADP)and adenosine triphosphate (ATP)were detected. Results(1) STⅡ changes: in 20 min of ligation, compared with the sham group, the STⅡ segment of electrocardiograph (ECG) was elevated significantly in the MIRI group and EA group (both P < 0.01), but the elevation range in the EA group was lower than that of the MIRI group (P < 0.01). After reperfusion for 30 min, the STⅡ segment was fallen by over 50% in the MIRI group and the EA group. Simultaneously, the STⅡ segment in the EA group was lower than that of the MIRI group (P < 0.01). (2) Regarding myocardial infarction weight percentage, compared with the sham group, the infarction weight was larger in the MIRI group and the EA group (both P < 0.05) and the infarction weight in the EA group was lower than that of the MIRI group (P < 0.05). (3) Regarding the levels of serum cTnt and cTnI, compared with the sham group, the levels of serum cTnT and cTnI were higher in the MIRI group and the EA group (all P < 0.01) and the levels of cTnT and cTnI in the EA group were lower than that of the MIRI group (both P < 0.01). (4) Regarding the concentrations of AMP, ADP and ATP, compared with the sham group, ATP concentration was lower in the MIRI group and the EA group (both P < 0.01) and the concentrations of AMP and ADP were higher (P < 0.05, P < 0.01). Compared with the MIRI group, ATP concentration was higher in the EA group (P < 0.05) and the concentrations of AMP and ADP were lower (both P < 0.01). ConclusionsElectroacupuncture pretreatment reduces the elevation of ECG STⅡ segment, decreases the concentrations of myocardial injury markers, cTnT and cTnI and regulates the transfer among AMP, ATP and ADP. The protective effect of electroacupuncture pretreatment may result from the regulation of mitochondrial energy metabolism.