The influence of L-arginine on circadian rhythm and circadianperiodgenes

To study the effect of L-arginine on circadian system, ICR mice and AR4-2J cells were treated with L-arginine. The locomotor activity of the mice intraperitoneally injected with a high dose of L-arginine was observed. We also detected effects of arginine on Per1 and Per2 gene expressions in AR4-2J cells. Double-plotted actograms were applied to analyze the locomotor activity of the mice, and reverse transcription-polymerase chain reaction (RT-PCR) was used in analysis of the expression of the major circadian genes Per1 and Per2 in AR4-2J cells. The results presented here indicate that the intraperitoneal injection of L-arginine would strongly disrupt the circadian rhythm of locomotor activity in mice. While the co-culture of L-arginine would also disturb the circadian rhythm of Per1 and Per2 genes which were induced by PMA in AR4-2J cells, the expression levels of both genes greatly decreased.