Objective: To synchronously investigate the effects of Shouwu Fang on the pharmacokinetics of levodopa (L-DOPA) in blood and in extracellular fluids of striatum in rat with Parkinson’s disease (PD)

by simultaneous blood-brain microdialysis in freely moving rats. Method: SD rats were randomly divided into four groups:control group

model group

L-DOPA group (ip L-DOPA 24 mg ·kg-1and benserazide 6 mg ·kg-1)

SWF+L-DOPA group (ip L-DOPA pretreated with ig SWF).The rat model of Parkinson’s disease was induced by injecting 6-hydrodopamine (6-OHDA) into striatum of rats

blood-brain microdialysis technique was used for simultaneously sampling.High performance liquid chromatography-fluorescence detector (HPLC-FLD) and high performance liquid chromatography-electrochemical detector (HPLC-ED) were used to detect the concentration of L-DOPA in blood and striatum.The data were analyzed with DAS program. Result: Compared with L-DOPA group

the blood L-DOPA concentration of SWF+L-DOPA group was increased significantly at 6 time points

the concentration in striatum was decreased at 15 min after drug administration.The blood pharmacokinetic parameters of L-DOPA group and SWF+L-DOPA group were as follows:AUC(1 627.7±420.57) mg ·L-1 ·min-1

(2 626.44±980.6) mg ·L-1.min-1

Tmax:30 min

(37.5±8.22) min

MRT(0-t);(71.98±3.19) min

(83.44±9.53) min

striatum pharmacokinetic parameters:Tmax:(50±15.49) min

(81±27.25) min

MRT(0-t);(68.65±15.39) min

(107.91±26.66) min.Compared with L-DOPA group

SWF+L-DOPA group blood AUC was increased (P<0.05)

Tmaxand MRT(0-t) were delayed (P<0.05);striatum Tmaxand MRT(0-t) were delayed too (P<0.05). Conclusion: Shouwu Fang delayed L-DOPA elimination

increased its absorption in blood

and reduced fluctuation of concentration in striatum.