Pharmacological study on circadian gene expression induced by sympathetic nervous activity in osteoblastic cells.

大多数生物体表现出昼夜节律，这些振荡是由存在于视交叉上核(SCN)的内源性生物钟产生的。来自SCN的输出信号被认为通过交感神经系统和体液途径将标准昼夜时间传递到周围组织。因此，我们研究了交感神经系统和糖皮质激素是否影响培养的成骨细胞的外周时钟。在本研究中，我们证明交感信号和糖皮质激素都是从SCN到周围组织的昼夜节律的中介。此外，这些交感神经和糖皮质激素影响一些成骨细胞相关基因的表达，这可能有助于骨骼代谢的昼夜节律。

Most living organisms exhibit circadian rhythms and these oscillations are generated by endogenous circadian clocks, present in the suprachiasmatic nuclei (SCN). Output signals from SCN are believed to transmit standard circadian time to peripheral tissue through symapathetic nervous system and humoral routes. So, we examined whether symapathetic nervous system and glucocorticoid affect peripheral clock in cultured osteoblast. In the present study, we demonstrated that both symapathetic signal and glucocorticoids are mediators of circadian rhythm from SCN to peripheral tissues. In addition, these sympathetic and glucocorticoids affect expressions of some osteoblast-related genes, which may contribute to circadian rhythms of bone metabolism