Objective: To observe the effect of Electroacupuncture (EA) stimulation of "Tianquan"(PC 2), "Quze" (PC 3), "Neiguan" (PC 6), "Daling" (PC 7) of the Pericardium Meridian on cerebral angiogenesis in cerebral ischemia (CI) rats, so as to reveal its mechanisms underlying improvement of stroke.
Methods: A total of 50 SD rats were equally randomized into normal control, sham, model, EA-Pericardium-Meridian acupoints (EA-PCM) and EA-Lung-Meridian acupoint (EA-LUM) groups. The CI model was established by occlusion of the middle cerebral artery. EA (2-4 V, 20 Hz) was applied to PC 2, PC 3, PC 6, PC 7 and "Tianfu"(LU 3), "Chize" (LU 5), "Lieque" (LU 7), "Taiyuan" (LU 9) of the Lung Meridian for 30 min, once at time-points of 0 h, 6 h, 24 h, 48 h and 72 h, respectively after modeling. Serum nerve growth factor (NGF) and Nogo protein-A (Nogo-A) contents were assayed by enzyme linked immunosorbent assay (ELISA), and cerebral NGF and Nogo-A immunoactivity levels in the ischemic cerebral tissue were detected by immunohistochemistry.
Results: (1) Compared to the normal control group, serum NGF and Nogo-A contents, and cerebral NGF immunoactivity level in the model group were significantly increased (P < 0.01). Following EA interventions, serum and cerebral NGF levels were further significantly up-regulated in the EA-PCM and EA-LUM groups (P < 0.01), while serum Nogo-A contents were down-regulated in the two EA groups (P < 0.01). The effect of EA-PCM was markedly superior to that of EA-LUM in up-regulating serum and cerebral NGF levels and down-regulating serum No- go-A level (P < 0.01). No significant differences were found between the normal control and sham groups in serum and cerebral NGF and Nogo-A levels (P > 0.05) , and among the 5 groups in cerebral Nogo-A levels (P > 0.05).
Conclusion: EA stimulation of acupoints of both Pericardium Meridian and Lung Meridian can up-regulate serum NGF, cerebral NGF expression and down-regulate serum Nogo-A in CI rats, and the effect of Pericardium Meridian is markedly superior to that of Lung Meridian, suggesting a possible better nerve repair effect of EA-PCM acupoints on ischemic brain.