Glycine is now used as a chemical for promotion of sleep in humans. It has been demonstrated that glycine administration up to 2g/kg causes the increase of NREM sleep in sleep disturbed rat and hypothermia (0.6 C decrease) in rat. The administration of benzodiazepine not only caused the sleep but affected the circadian rhythm; it blocked the light-induced phase advance of activity rhythm and elevation of Per1 gene expression in the suprachiasmatic nucleus (SCN) in hamsters. In the present experiment, we examined the possibility whether glycine affect light-induced phase shift and c-fos expression in the SCN and retina of mice. Glycine dose-dependently decreased the body temperature of mice (1C decrease with 2 g/kg). After extended light exposure for 2 hrs in the night under LD cycle mouse was kept under constant dark condition. Glycine (0.5-2 g/kg) pretreatment before light exposure dose-dependently attenuated light-induced phase delay. Glycine (2g/kg) pretreatment slightly attenuated light-induced increase of Fos immunoreactivity in the mouse SCN. Further experiment should elucidate whether glycine administration itself causes the phase shift or not. The present results suggest that high dose of glycine may attenuate the light-induced phase shift of circadian clock. <b>[J Physiol Sci. 2008;58 Suppl:S90]</b>
1 0 0 0 栄養素摂取によって引き起こされるマウス肝臓時計遺伝子発現リズム
Daily restricted feeding (RF) with fixed time during daytime causes an advance of circadian rhythm of mouse liver clock gene expression. However, the mechanism of entrainment signal is poorly understood. Here, we examine whether daily administration of various type of nutrition caused entrainment of liver clock gene expression rhythm using Bmal1-luciferase transgenic mouse. Circadian rhythm change of liver bioluminescence was recorded through Lumicycle after 1-6 days of administration of various nutrients. We administered the corn carbon dehydrate, egg albumin or soybean oil after adjustment of each calorie. Among these nutrients soybean oil has most strong effect on phase-shift of gene expression rhythm. Administration of glucose through oral or intraperitoneal caused the phase advance, however the value of change was small. Thus, slow supply of calorie may be important to cause phase shift. We still examine the other nutrients such as amino acids, dextrin and sugar. We also try to find the effect of combination of nutrients on phase-shift of liver clock. <b>[J Physiol Sci. 2008;58 Suppl:S198]</b>