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.