[Effect of electroacupuncture preconditioning on myocyte apoptosis in myocardial ischemia-reperfusion injury rats based on FXR/SHP pathway].

OBJECTIVE: To observe the effect of electroacupuncture (EA) preconditioning on left-cardiac function, contents of serum TNF-α and IL-6 and expression of myocardial farnesoid X receptor(FXR), small heterodimer partner (SHP), apoptosis inducing factor (AIF) and heat shock proteins 70 (HSP70) genes in myocardial ischemia-reperfusion injury (MIRI) rats, so as to explore its mechanisms underlying improvement of ischemic myocardial injury. METHODS: Forty male Wistar rats were randomly divided into normal control, sham operation, MIRI model and EA pretreatment groups, with 10 rats in each group. Rats of the sham operation group received exposure of the thorax and heart. The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery (LAD). EA (2 Hz/100 Hz and 1 mA) was applied to bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, once a day for 7 days. The left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP)and maximal rates of rise and fall of left ventricular pressure (±dp/dtmax) were detected, the contents of serum TNF-α and IL-6 were detected by using enzyme-linked immunosorbent assay (ELISA), and the expression of FXR, SHP, AIF and HSP70 apoptotic genes in the myocardial tissue were measured by fluorescent quantitative RT-PCR. RESULTS: Compared with the normal control group, the LVEDP, contents of serum TNF-α and IL-6, and the expression levels of myocardial FXR, SHP, AIF and HSP70 mRNAs were significantly increased (P<0.05), while LVSP and ±dp/dtmax levels were obviously decreased in the model group (P<0.05). In comparison with the model group, MIRI-induced increases of LVEDP, TNF-α and IL-6 contents, and FXR, SHP and AIF mRNA expression and decreases of ±dp/dtmax and LVSP levels were reversed(P<0.05), except HSP70 mRNA expression with significantly increased (P<0.05) in the EA pretreatment group. CONCLUSION: EA pretreatment can protect the left ventricular function of the ischemic heart in MIRI rats, which may be related to its effects in reliving peripheral inflammation and regulating the expression levels of apoptosis-related factors FXR, SHP, AIF and HSP70 in the myocardium.

[Effect of electroacupuncture preconditioning on cell apoptosis mediated by mitochondrial reactive oxygen species in myocardial ischemia/reperfusion injury rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) preconditioning on cell apoptosis and the content of mitochondrial reactive oxygen species (ROS) in rats with myocardial ischemia/reperfusion injury (MIRI), so as to explore their mechanisms underlying improvement of MIRI. METHODS: Eighty male Wistar rats were randomly divided into control, sham, ischemia reperfusion (IR) and EA groups, with 20 rats in each group. Rats of the control, sham and IR groups were just banded on the boards for 30 min, once daily for 7 days. Before modeling, EA (2 Hz, 1 mA) was applied to "Neiguan" (PC6), "Zusanli" (ST36), "Guanyuan"(CV4) for 20 min, once daily for 7 successive days in the EA group. The MIRI model was established by occlusion of the left anterior descending branch of the left coronary artery for 20 min, followed by reperfusion for 30 min. Ventricular arrhythmia (VA) score was used to evaluate arrhythmia. Enzyme-linked immunosorbent assay (ELISA) was used to detect the level of CK-MB. DHE staining was used to detect the content of reactive oxygen species (ROS). The gene expression levels of cytochrome C (Cyt-C), Caspase-9 and Caspase-3 were detected by real-time fluorescent quantitative PCR. RESULTS: Compared with the sham group, VA score, serum CK-MB content, ROS content in heart tissue and Cyt-C, Caspase-9 and Caspase-3 gene expression were significantly up-regulated in the MIRI group (all P<0.01). Following the intervention, the increased VA score, serum CK-MB content, ROS content in heart tissue, Cyt-C, Caspase-9 and Caspase-3 gene expression were all reversed in the EA group compared with the MIRI group (all P<0.01). CONCLUSION: The protective effect of EA preconditioning on MIRI may be based on the regulation of ROS mediated-apoptosis pathway.

[Protective effect and regulating effect on FXR/SHP gene of electroacupuncture preconditioning on myocardial ischemia-reperfusion injury in rats].

OBJECTIVE: To explore the protective mechanism of electroacupuncture preconditioning on myocardial ischemia-reperfusion injury in rats. METHODS: A total of 88 SPF-grade Wistar male rats were randomized into a normal group, a sham-operation group, a model group and an electroacupuncture (EA) group, 22 rats in each one. The rats in the normal group received normal diet and no intervention was given for 7 d. The rats in the sham-operation and the model group were bound for 20 min, once a day for 7 d. In the EA group, EA, continuous wave, 2 Hz and 1 mA, was applied at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) for 20 min, once a day for 7 d. In the 8th day, the blood was collected by abdominal aortic method 60 min after intraperitoneal injection of 10% urethane anesthesia by 10 mL/kg in the normal group, and then the tissue of heart was collected. In the model group and the EA group, ligating the left anterior descending coronary artery (LAD) was adopted for 20 min and reperfusion was applied for 40 min, then the samples were collected. The rats in the sham-operation group recevied open-chest operation and no other intervention, the samples were collected in 60 min. Nitro Blue Tetrazolium Chloride monohydrate (NBT) stain was used to detected myocardial infarct size and weight, ELISA was used to measured myocardial injury markers and inflammatory factors (LDH、CK、cTnI), and the fluorescent quantitative PCR method was used to determine the expressions of FXR and SHP gene. RESULTS: ①There was no significant difference between the normal group and the sham-operation group in myocardial infarct size and weight (P>0.05) .Compared with the normal group, myocardial infarct size and weight were higher in the model group (P<0.01). Compared with the model group, myocardial infarct size and weight were lower in the EA group (P<0.01). ②There was no significant difference between the normal group and the sham-operation group in serum contents of LDH、CK、cTnI (P>0.05). Compared with the normal group, the serum contents of LDH、CK、cTnI were higher in the model group (P<0.05). Compared with the model group, the serum contents of LDH、CK、cTnI were lower in the EA group (P<0.05). ③The expressions of FXR and SHP gene in the model group were higher than those in the normal group (P<0.05). The expressions of FXR and SHP gene in the EA group were lower than those in the model group (P<0.05). CONCLUSION: Electroacupuncture preconditioning could significantly improve cardiac function of rats with myocardial ischemia-reperfusion, reduce infarct size and inflammatory factors, and down-regulate the expressions of FXR and SHP gene. The protective effect may generate based on regulation of FXR/SHP apoptosis signal pathway.