Fluoxetine-induced Changes on Activity of Tryptophan Hydroxylase at RBL-2H3 Cells / 대한정신약물학회지

ABSTRACT

OBJECTIVES: The aim of the present study is to explore the effect of fluoxetine on transcription, translation and activity of tryptophan hydroxylase (TPH), and intracellular level of serotonin. METHODS: The expression level of the TPH mRNA and the protein, the TPH enzyme activity, and the intracellular level of serotonin were explored at the fluoxetine-treated RBL-2H3 cells. Real-time RT-PCR and immunoblotting analysis confirmed changes in the expression of TPH mRNA and protein. The activity of TPH was measured using [3H]tryptophan. The intracellular level of serotonin was measured by HPLC. RESULTS: The TPH activity was gradually increased on time from 24hr to 72hr. The real-time RT-PCR also revealed that the TPH mRNA was increased at 12, 24 and 72hr in the fluoxetine-treated RBL-2H3 cells. The immunoblotting analysis also revealed that the TPH protein was decreased at 72hr in the fluoxetine-treated RBL-2H3 cells. The intracellular level of serotonin was increased at 48hr after treatment of fluoxetine. CONCLUSION: Fluoxetine induced the increases of the TPH mRNA, the TPH enzyme activity and intracellular level of serotonin, and the decrease of the TPH protein expression at the RBL- 2H3 cells.