Objective To observe the effect of electroacupuncture(EA) on the cardiac function

lymphatic markers

macrophage and inflammatory cytokines in acute myocardial ischemia(AMI) mice

so as to explore its mechanism in improving AMI. Methods Male C57 BL/6 mice were randomly divided into sham operation

model

EA

inhibitor and inhibitor+EA groups

with 10 mice in each group. AMI model was established by occlusion of left anterior descending coronary artery. For mice in the EA group and inhibitor+EA group

EA(1 mA

2 Hz/15 Hz) was applied to bilateral “Shenmen”(HT7) and “Tongli”(HT5) for 30 min

once daily for consecutive 3 days. Mice in the inhibitor+EA group were given intraperitoneal injection of vascular endothelial growth factor receptor-3(VEGFR-3) inhibitor SAR131675 30 min before the EA

while mice in the inhibitor group were given intraperitoneal injection of SAR131675 only. The electrocardiogram(ECG) of the neck-thoracic lead was recorded and analyzed by BL-420 F biological function experiment system. Histopathologic changes of myocardial tissue were observed after H.E. staining. The contents of lactate dehydrogenase(LDH)

cardiac troponin I(cTnI) in serum and interleukin-18(IL-18) and interleukin-6(IL-6) in ischemic myocardium were determined by ELISA. The expressions of hyaluronic acid receptor-1(LYVE-1) and macrophage mar-ker CD68(CD68) in the myocardial tissue were detected by immunofluorescence assay. The protein expression levels of vascular endothelial growth factor C(VEGF-C) and VEGFR-3 were detected by Western blot. Results Compared with the sham operation group

the ECG-ST level

the contents of serum LDH and cTnI

and the contents of IL-18 and IL-6 in the myocardial tissue were significantly increased(P<0.01)

the expression of LYVE-1 and the protein expression levels of VEGF-C and VEGFR-3 in the myocardial tissue were significantly decreased(P<0.01)

while the number of CD68 positive cells was significantly increased(P<0.01) in the model group. Compared with the model

inhibitor and inhibitor+EA groups

the ECG-ST level

the contents of serum LDH and cTnI

and the contents of IL-18 and IL-6 in the myocardial tissue were decreased(P<0.01)

the expression of LYVE-1 and the expression level of VEGFR-3 protein were increased(P<0.01)

while the number of CD68 positive cells was significantly decreased(P<0.01) in the EA group. Compared with the model and inhibitor groups

the expression level of VEGF-C was increased(P<0.01) in the EA group. Outcomes of H.E. staining showed that the myocardial fibers were disordered with a large number of inflammatory cell infiltration in the model group

which was milder in the EA group. Conclusion Acupuncture can improve the inflammatory injury of AMI mice

which may be related to activate VEGF-C/VEGFR-3 pathway to promote lymphangiogenesis

reduce macrophage infiltration and inflammatory factors.