Electroacupuncture of “Shenmen”（HT7） regulates the pyruvate-lactate metabolic axis to improve myocardial injury in acute myocardial ischemia rats

ObjectiveTo explore the underlying mechanism of electroacupuncture （EA） of “Shenmen” （HT7） in amelioration of myocardial injury by regulating pyruvate-lactate metabolic axis in rats with acute myocardial ischemia （AMI）.MethodsSD rats were randomly divided into sham operation （sham）， AMI model （model）， EA， monocarboxylic acid transporter 4 （MCT4） inhibitor group and EA+mitochondrial pyruvate vector （MPC） inhibitor groups， with 6 rats in each group. The AMI model was made by ligating the left anterior descending coronary artery. EA （2 Hz， 1 mA） was applied to bilateral HT7 for 30 min， once a day for 3 days. Both MCT4 and MPC inhibitors were separately given to rats of the MCT4 inhibitor and EA+MPC inhibitor groups by intraperitoneal injection， once a day for 3 d. The HE staining was used to observe the histopathological changes of the myocardium tissue. The Sirius red staining was used to observe the myocardial fibrosis. The left ventricular ejection fraction（EF） and fractional shortening （FS） were detected by echocardiography. The contents of serum brain natriuretic peptide （BNP）， lactic acid， lactate dehydrogenase （LDH）， and myocardial lactic acid and LDH were detected by ELISA. The ultrastructure of mitochondria in the myocardial cells was observed by transmission electron microscopy. The protein expressions of MCT4， MPC and pan-lysine lactylation （Pan-Kla） in the myocardium were detected by Western blot.ResultsCompared with the sham group， the model group had a striking decrease in the levels of EF and FS and MPC protein expression （PPPPPPConclusionEA of HT7 can improve myocardial energy metabolism and cardiac functional injury in rats with AMI， which may be related with its functions in inhibiting myocardial lactate excretion， mitigating lactate accumulation and lactylation by down-regulating MCT4， up-regulating MPC to promote pyruvate mitochondrial oxidation and energy supply， and modulating the pyruvate-lactic acid metabolic axis.