| Objective:To observe the effect of electroacupuncture preconditioning(EAP)on TRPV1/CGRP signaling pathway and expression of related inflammatory mediators in myocardial tissue of rats with acute myocardial ischemia(AMI)injury,and to explore the possible mechanism of electroacupuncture preconditioning against AMI injury.Methods:Adult male SD rats were randomly divided into blank group,sham operation group,model group and model+electroacupuncture group(electroacupuncture group for short).Acute myocardial ischemia model was established by left anterior descending coronary artery(LAD)ligation in model group and electroacupuncture group,while in the sham group,the thread was only threaded under the LAD without ligation.Rats in the electroacupuncture group were selected from bilateral "Neiguan" acupoint for electroacupuncture intervention before modeling,frequency 2Hz/100Hz,intensity 2mA,20min each time,once daily for 7 days.Electrocardiogram(ECG)was recorded by physiological signal acquisition system to observe the ST segment potential offset of standard limb II lead before,30 min after and 24h after surgery.HE staining and Immunohistochemical(IHC)staining were used to observe the inflammation level in the myocardial infarction area of rats.The expression of inflammatory cytokines TNF-α and IL-10 was detected by ELISA.TRPV1/CGRP signal and p65 protein expression in myocardial infarction area were detected by Western blot(WB)method.The co-expression of TRPV1 and CGRP in myocardial infarction area was observed by immunofluorescence(IF)staining method.Results:1)Compared with the blank group,the ECG-J point potential of the sham group at 30min and 24h after operation was not significantly changed(P>0.05),while the position of ECG-J point was significantly increased in the model group 30min after operation(P<0.001),the ECG-J site was significantly reduced 24h after operation(P<0.001).2)Compared with the blank group,the left ventricular EF value and myocardial infarction area were almost unchanged at 24h after operation in the sham operation group(P>0.05),while the left ventricular EF value was significantly decreased and the myocardial infarction area wassignificantly increased in the model group(P<0.01).Compared with model group,the left ventricular EF value increased and myocardial infarct area decreased in electroacupuncture group(P<0.01).3)Compared with blank group,the expression of neutrophils and global inflammatory cell infiltration,p65 protein and inflammatory factors TNF-α and IL-10 in myocardial tissue were slightly increased in sham group 24h after operation(P>0.05),while the expression of neutrophils and global inflammatory cell infiltration,p65 protein and inflammatory factors TNF-α and IL-10 were increased in model group(P<0.05).Compared with the model group,the levels of neutrophils and overall inflammatory cell infiltration,the expression of p65 protein and inflammatory factor TNF-α in cardiac tissue were decreased,and the content of IL-10 was increased in electroacupuncture group(P<0.05).4)Compared with the blank group,the expression of TRPV1/CGRP signal protein and its coexpression were slightly increased in the sham group 24h after operation(P>0.05),and significantly increased in the model group(P<0.01).Compared with the model group,the expression of TRPV1/CGRP signal protein and coexpression were further increased in the electroacupuncture group(P<0.01).Conclusion:1)EAP could exert exert the cardioprotective effect on AMI injury in rats.2)EAP against AMI myocardial injury may be related to reducing neutrophils accumulation,regulating the activation of NF-κB pathway,inhibiting the release of pro-inflammatory factor TNF-α and upregulating the content of anti-inflammatory factor IL-10.3)EAP may play a cardioprotective role by enhancing the expression of TRPV1/CGRP signaling pathway in ischemic myocardium,regulating the inflammatory cell infiltration and the expression of related inflammatory mediators in ischemic myocardium in the acute stage of myocardial ischemia. |
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