期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：11
页码：6795-6800
DOI：10.1073/pnas.0936797100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A main oscillator in the suprachiasmatic nucleus (SCN) conveys circadian information to the peripheral clock systems for the regulation of fundamental physiological functions. Although polysynaptic autonomic neural pathways between the SCN and the liver were observed in rats, whether activation of the sympathetic nervous system entrains clock gene expression in the liver has yet to be understood. To assess sympathetic innervation from the SCN to liver tissue, we investigated whether injection of adrenaline/noradrenaline (epinephrine/norepinephrine) or sympathetic nerve stimulation could induce mPer gene expression in mouse liver. Acute administration of adrenaline or noradrenaline increased mPer1 but not mPer2 expression in the liver of mice in vivo and in hepatic slices in vitro. Electrical stimulation of the sympathetic nerves or adrenaline injection caused an elevation of bioluminescence in the liver area of transgenic mice carrying mPer1 promoter-luciferase. Under a light-dark cycle, destruction of the SCN flattened the daily rhythms of not only mPer1, mPer2, and mBmal1 genes but also noradrenaline content in the liver. Daily injection of adrenaline, administered at a fixed time for 6 days, recovered oscillations of mPer2 and mBmal1 gene expression in the liver of mice with SCN lesion on day 7. Sympathetic nerve denervation by 6-hydroxydopamine flattened the daily rhythm of mPer1 and mPer2 gene expression. Thus, on the basis of the present results, activation of the sympathetic nerves through noradrenaline and/or adrenaline release was a factor controlling the peripheral clock.
