To observe the influence of electroacupuncture (EA) therapy on the expression of tyrosine hydroxylase (TH) and cyclooxygenase-2 (COX-2) proteins of Substantia Nigra cells(SNc) in the rotenone-induced Parkinson's disease(PD) rats, so as to explore the mechanism of EA underlying improvement of PD.
Forty rats were randomly divided into normal, sham-operation (sham), model and EA groups (n = 10/group). The PD model was established by successive subcutaneous injection of rotenone (highly selective lesions of nigrostriatal dopaminergic neurons) for 28 days. EA (2 Hz, 1 mA) was applied to bilateral "Fengfu" (GV 16) and "Taichong" (LR 3) for 20 min, once daily for 14 days. The expression levels of TH and COX-2 proteins in the Substantia Nigra of midbrain were detected with Western blotting.
Compared with the normal group, the expression level of TH protein in the model group was significantly decreased (P < 0.01), and that of COX-2 protein in the model group was significantly increased (P < 0.01). After the EA treatment, the expression level of TH in the EA group was obviously upregulated (P < 0.01), and that of COX-2 protein in the EA group was considerably down-regulated (P < 0.01). No significant differences were found between the normal and sham groups in the expression levels of TH and COX-2 proteins (P > 0.05).
EA therapy can decrease inflammation mediator COX-2 protein expression and upregulate TH protein expression in the Substantia Nigra of midbrain in PD rats, which may contribute to its effect in relieving PD in clinic.