[Dynamic changes of dopamine and its metabolite levels in the rat striatum after cerebral ischemia-reperfusion and electroacupuncture].

Objective To explore the involvement of dopamine(DA) and its metabolites in the extracellular fluid of the striatum on the resisting action of electroacupuncture(EA) for acute cerebral ischemia-reperfusion(CI/R) injury.Methods A total of 50 SD male rats were randomly divided into normal control,sham-operation(sham),sham+EA,CI/R model,CI/R+EA groups.CI/R model was induced by right middle cerebral artery occlusion(MCAO) for 90 min and reperfusion for 225 min.EA (2 Hz,3 mA,continuous waves) was applied to"Fengchi"(GB 20) for 20 min,with a 10 min rest,and given once again for 20 min.The concentrations of DA and its metabolites[3,4- dihydroxy-phenyl acetic acid(DOPAC) and homovanillic acid(HVA)] in the extracellular fluid of the striatum were determined by microdialysis and high performance liquid chromatography(HPLC). Results The extracellular levels of DA,DOPAC and HVA in normal group,sham group and sham+EA group had no significant changes during the whole study.The extracellular level of DA peaked 15-45 min after Cl and 0-30 min after CI/R(P0.05). A rising trend was also observed 120 min following CI/R.DOPAC level peaked 15 min and 75 min after CI and 75 min after CI/R. After EA,DA level was significantly lower in EA group than that in model group 90 min after CI/R(P0.05),and no peak was observed again.After EA,DOPAC level maintained its basic level,and no peak was found after CI/R.The changing trend of HVA was similar to that of DOPAC,and the extracellular HVA level in EA + model group was significantly lower than that in model group 75 min after CI/R.Conclusion EA can decrease the accumulation of DA and its metabolites in the extracellular fluid of the striatum, which may contribute to its effect in preventing the brain from CI/R injury.