Objective To observe the effect of Ditan Decoction（Phlegm-dissolving decoction）on dopamine transporter（DAT）in striatum of Parkinson’s disease（PD）rats with side-effects by Levodopa（LD）.Methods Based on the PD model rats LD models were made through intraperitoneal injection of LD for 2 weeks.The successfully made LD models were randomized into LD model group and Ditan Decoction group

9 rats for each group.And the normal control group and PD model group were set up for comparison

9 rats in each group.The LD model group and Ditan Decoction group were given normal saline and Ditan Decoction respectively by intragastric feeding.PD model group and normal control group were given normal saline by intragastric feeding.In the 2nd

4th

and 6th week

3 rats were taken from each group for the examination of DAT autoradiography in striatum with 125I-β-CIT and the determination of DAT radioactivity with γ-counter.Results With the time going on

the number of DAT of the LD model group had the tendency of decrease

and in the 4th and 6th week

it was lower than in the PD model group.While the number of DAT of the Ditan Decoction group had the tendency of increase

and in the 4th and 6th week

it was higher than in the LD model group.But the difference was not significant（P>0.05）.The result of autoradiography was basically consistent with it.Conclusion Ditan Decoction might be effective against the decrease of DAT caused by LD treatment of PD.