To investigate the effect of serotonin uptake inhibitor

clomipramine

on binding of dopamine transporter ligand

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I-β-CIT in mouse brain. Dose-dependant changes in

125

I-β-CIT specific binding induced by clomipramine were studied in the striatum （rich in DAT）

frontal cortex and brain stem （rich in 5-HTT）. Changes in the time-activity curves of

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I-P-CIT specific binding after clomipramine injection were also examined. The specific binding of

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I-β-CIT in brain stem

hippocampus

frontal cortex was inhibited significantly （vs controls P

<

0.01）

while the binding in the striatum was greater than contyols. The binding in brain stem

frontal cortex and hippocampus were inhibited at all time points （from 5 minutes to 8h）

while the binding in the striatum were enhanced from 5min to 8h except at 6h. Enhancement of

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I-β-CIT binding in the striatum after clomipramine treatment indicates there was the possibility of interaction between serotonin and dopamine system. The uptake of

125

I-β-CIT in brain is reduced by clomipramine administration and this result has not yet reported in literatures.