ObjectiveTo explore the role of the ferroptosis pathway in myocardial cells in the improvement of myocardial ischemia in rats by electroacupuncture at the "Xinshu" （BL 15）.Methods18 SD rats were randomly divided into the control group， the model group， and the electroacupuncture group， with 6 rats in each group. The model group and the electroacupuncture group were injected with 60 mg/kg isoproterenol （ISO） subcutaneously for consecutive two days to establish a myocardial ischemia （MI） rat model， while the control group was injected with the same volume of 0.9% sodium chloride solution. After the model was successfully established， the bilateral "Xin shu"（BL 15）were selected for intervention on the rats in the electroacupuncture group. The treatment involved sparse and dense waves， with a frequency of 2 Hz/10 Hz， each session lasting 30 minutes， once a day， for a total of 3 days. The electrocardiogram （ECG） changes of the rats during the three stages before modeling， after modeling， and after intervention were recorded using a multi-channel physiological recorder； the histological changes of the rat myocardial tissue were observed using hematoxylin-eosin staining （HE staining）； the ultrastructural changes of the myocardial cell mitochondria were observed under a transmission electron microscope （TEM）； the contents of divalent iron ions （Fe²⁺）， malondialdehyde （MDA）， and glutathione （GSH） in the myocardial tissue， as well as the activities of superoxide dismutase （SOD） and glutathione peroxidase （GSH-PX）， were detected using biochemical methods； the mRNA and protein expression levels of ferritin heavy chain 1 （FTH1）， nuclear factor E2-related factor 2 （Nrf2）， cystine/glutamate antiporter （SLC7A11）， glutathione peroxidase 4 （GPX4） and acyl-CoA synthetase long-chain family member 4 （ACSL4） in the myocardial tissue of each group of rats were detected using real-time fluorescence quantitative PCR （RT-qPCR） and Western blot.ResultsCompared with the control group， the ECG S-T segment elevation was observed in the model group and the electroacupuncture group （P < 0.01）； the myocardial tissue of the model group showed pathological changes， with increased mitochondrial density and reduced cristae； The content of Fe²⁺ in the myocardial tissue increased （P < 0.01）， while the levels of GSH， the activities of SOD and GSH-PX all decreased （P < 0.01）.； the mRNA expression levels of FTH1， Nrf2， SLC7A11， and GPX4 in the myocardial tissue were all decreased （P < 0.01）， while the mRNA expression level of ACSL4 increased （P < 0.05）； the protein expression levels of FTH1， Nrf2， SLC7A11， and GPX4 in the myocardial tissue were all decreased （P < 0.01）， while the protein expression level of ACSL4 increased （P < 0.01）. Compared with the model group， the ECG S-T segment of the electroacupuncture group returned to the normal value （P < 0.01）； the pathological changes of myocardial cells were alleviated， with reduced mitochondrial density and decreased degree of cristae reduction； the content of Fe²⁺ in the myocardial tissue decreased （P < 0.05）， while the contents of GSH and the activities of SOD and GSH-PX increased （P < 0.01， P < 0.05）； the mRNA expression levels of FTH1， Nrf2， SLC7A11， and GPX4 in the myocardial tissue were all increased （P < 0.01）， while the mRNA expression level of ACSL4 decreased （P < 0.05）； the protein expression levels of FTH1， Nrf2， SLC7A11， and GPX4 in the myocardial tissue were all increased （P < 0.01， P < 0.05）， while the protein expression level of ACSL4 decreased （P<0.01）.ConclusionThe protective effect of electroacupuncture at the "Xinshu" （BL15） on ischemic myocardium may be achieved by inhibiting the ferroptosis pathway in myocardial cells.

Myocardial ischemia;Electroacupuncture;Xinshu （BL15）;Ferroptosis