The inhibitory effects of deltamethrin on dopamine biosynthesis in rat PC12 cells.

The inhibitory effects of deltamethrin (DM) on dopamine biosynthesis in PC12 cells were investigated. Levels of dopamine in PC12 cells were detected after treatment with different doses from 10(-4)M to 10(-6)M deltamethrin or combined with 20 microM or 50 microM l-3,4-dihydroxyphenylalanine (L-Dopa) for 3 h or 12 h by HPLC. Flow cytometry (FCM) and RT-PCR technology were used to detect the levels of tyrosine hydroxylase (TH) mRNA and protein in PC12 cells treated with different doses of deltamethrin for 3 h or 12 h. Deltamethrin decreased the levels of dopamine, TH mRNA and TH protein in PC12 cells, and the increased dopamine levels induced by l-Dopa at 20-50 microM were also decreased by deltamethrin for 3 h or 12 h. These results indicate that deltamethrin decreases dopamine content by the inhibition of TH mRNA and protein level in PC12 cells and maybe also have inhibitory effect on aromatic l-amino acid decarboxylase.