Abstract: Objective To study the mPer1 mRNA expression profiles in striatum and other brain regions in MPTP-treated mice. Methods Sixty C57 BL/6J male mice were randomized into MPTP and control groups. For MPTP group, MPTP-HCL was administered intraperitoneally in 5 consecutive days. For the control group, MPTP-HCL was replaced by same volume of saline. On the 11th day, mice were sacrificed at six different time points during a 24-hour periods, and striatum and the rest of brain regions were isolated. Dopamine levels of striatum were measured using HPLC-ECD. The mRNA expression of mPer1 was examined using real time PCR. Results The dopamine levels in striatum decreased about 80% in MPTP-treated mice, which remained at low level for up to 10 days. The expression of mPer1 mRNA in striatum increased significantly in MPTP-treated mice, with the rhythmic expression phase being shifted. Compared with control mice, the expression peak reached 4 hours earlier. The mPer1 mRNA expression in the rest of brain regions was also increased significantly in MPTP-treated mice, but no rhythmic changes occurred. Conclusion MPTP can change the mRNA expression of mPer1 in the striatum and the rest of brain regions, indicating that MPTP may affect the intracellular circadian oscillator in the brain.

Key words: clock gene, mPer1, Parkinson's disease, circadian rhythm