Chin Med J (Engl). 2000 May; 113(5): 408-11.

Comparative study of D2 receptors and dopamine content in striatum before and after electro-acupuncture treatment in rats.

Lin Y, Lin X.

Huashan Hospital, Shanghai Medical University, Shanghai 200040, China.

OBJECTIVE: To evaluate the change in D2 receptors and their relationship with dopamine (DA) content in experimental hemi-parkinsonism rats before and after electro-acupuncture (EA) treatment. METHODS: 125I-IBZM D2 receptor cerebral autoradiographic analysis, HPLC-ECD detection of DA and its metabolites, homovanillic acid (HVA), 3, 4-dihydroxyphenylacetic acid (DOPAC) were used to study their levels in striatum in pre-EA, EA and EA control group. RESULTS: The DA, HVA and DOPAC levels in striatum of the lesioned side in the EA group were elevated compared to the pre-EA and EA control group (P < 0.05). For the EA group, the striatum/cerebellum 125I-IBZM uptake ratio of the lesioned side was 8.04 +/- 0.71, (29.34% +/- 4.83%) more than that of the contralateral side (P < 0.05), while no significant difference was observed as compared with that in the pre-EA group (8.09 +/- 0.52, 30.12% +/- 4.53%, higher than that of the intact side P > 0.05). It was lower than the EA control group (8.61 +/- 0.63, P < 0.05), and the latter was (38.63% +/- 3.71%) higher than that in its contralateral side (P < 0.05). CONCLUSION: 6-OH-DA lesions in the substantia nigra and ventral tegmental areas induce an up-regulation of striatal D2 binding sites. EA treatment could elevate the DA level of the lesioned side striatum and prevent D2 receptor up-regulation in rats with experimental hemiparkinsonism.