[Effect of electroacupuncture on the contents of excitatory amino acids in cerebral tissue at different time courses in rats with cerebral ischemia and reperfusion injury].

OBJECTIVE

To observe changes of contents of excitatory amino acids in focal cerebral ischemic tissue after electroacupuncture (EA) treatment at different time courses in cerebral ischemia and reperfusion (CI/R) rats so as to provide experimental evidence for selecting the best duration of EA stimulation in the treatment of apoplexy.

METHODS

Forty SD rats were randomized into control, model, EA-10 min, EA-30 min and EA-60 min groups. CI/R model was established by middle cerebral artery occlusion (MCAO) and reperfusion. EA (2 Hz, 3.5 mA and continuous waves) was applied to "Baihui" (GV 20) and "Shuigou" (GV 26) for 10 min, 30 min and 60 min respectively. Cerebral glutamate (Glu) and aspartic acid (Asp) concentrations were detected by using an amino acid automatic analyzer after homogenate and centrifugalization of the right brain tissue.

RESULTS

Compared with control group, Asp and Glu contents of model group and EA-10 min group increased significantly (P < 0.01); while in comparison with model group, Asp level in EA-60 min group, and Glu level in EA-10 min, EA-30 min and EA-60 min groups decreased considerably (P < 0.05). No significant differences were found between control and EA-30 min groups, and between control and EA-60 min groups in Asp and Glu levels (P > 0.05).

CONCLUSION

EA of GV20 and GV26 for 60 min can markedly reduce Glu and Asp levels in the topical cerebral infarct area in CI/R rats, which may contribute to its effect in relieving cerebral ischemic injury. Suitable duration of EA stimulation is definitely necessary for inducing a better therapeutic effect.