Levodopa induces AP‐1 and CREB DNA‐binding activities in the rat striatum

In order to elucidate the effect of levodopa and bromocriptine on the DNA‐binding activities of transcription factors, AP‐1 and CREB DNA‐binding activities were investigated using gel‐shift assay. Intraperitoneal administration of 100 mg/kg levodopa with 50 mg/kg benserazide in rats increased both AP‐1 and CREB DNA‐binding activities in the dorsolateral aspect of the striatum. The major proteins composing the increased AP‐1 were JunB and JunD. Bromocriptine at doses of 2.5 and 5.0 mg/kg, however, did not increase these binding activities. Present results suggest that levodopa but not bromocriptine induces these transcription‐regulating proteins in the striatum with normal dopaminergic functioning.