Abstract: Objective To study the effect of ethonal on the dopaminergic system by analyzing the altered expression of tyrosine hydroxylase (TH) and dopamine transporter (DAT) in the brain of ethanol-treated rats. Methods Sixty Wistar rats were selected and divided into control group and ethanol-treated group, 30 per group, the ethanol-treated rats were treated with 20% ethanol for 6 months. Immunohistochemistry, flow cytometry and Western blotting were used to analyze the altered expression of TH and DAT in the DA energic system in different brain regions of the ethanol treated rats. Results 1. Immunohistochemistry showed the mean gray value of TH in substantia nigra(SN)-ventrotegmental area (VTA), caudae putamen (CPu) and nucleus accumbens (NACC), DAT in CPu and NACC of the ethanol were smaller than those in control (P<0.05). 2. Flow cytometry showed the expression of TH in middle brain of the ethanol-treated rats increased significantly compared with the control(EM>P/EM><0.05). 3. Western blotting showed the ratio of IA of TH/β-actin and DAT/β-actin in different brain regions of the ethanol-treated rats were larger than those in control(EM>P/EM><0.05).Conclusion Ethanol treatment increases the expression of TH and DAT in rat brain.

Key words: Ethanol, Tyrosine hydroxylase, Dopamine transporter, Immunohistochemistry, Flow cytometry, Western blotting, Rat