Wu T, Ni Y, Zhuge F, Fu Z
College of Biological and Environmental Engineering, Zhejiang University of Technology, Zhejiang, China.
Physiol Res. 2010;59(4):581-590. doi: 10.33549/physiolres.931818. Epub 2009 Nov 20.
To investigate the effect of light cue on the resetting of the peripheral clocks, we examined the resetting processes of clock genes (Per1, Per2, Bmal1, Cry1, Dec1, and Rev-erbalpha) in the liver and heart of rats after the feeding and light-dark (LD) reversal via a 24-h light period transition. The liver clock was reset quickly within 3 days, while the heart clock needed a longer time course of 5-7 days to be completely re-entrained. Moreover, the re-entrainment of Per1 and Per2 in the liver clock was more rapid than that of the other four clock genes, suggesting the important role of these two clock genes in initiating the circadian resetting of the hepatic clock. However, the resetting rates of these two clock genes were as similar as the others in the heart clock. Therefore, the resetting mechanisms underlining these two peripheral clocks may be totally distinct. Furthermore, the re-entrainment of the liver and heart clocks were relatively lengthened after the feeding and LD reversal via a light period transition compared to a dark period transition, suggesting a simultaneous shift of feeding schedule and the LD cycle may facilitate the circadian resetting in rats.
为了研究光信号对外周生物钟重设的影响，我们通过24小时光照周期转换，检测了喂食和明暗（LD）颠倒后大鼠肝脏和心脏中生物钟基因（Per1、Per2、Bmal1、Cry1、Dec1和Rev-erbalpha）的重设过程。肝脏生物钟在3天内迅速重设，而心脏生物钟需要5至7天的较长时间才能完全重新同步。此外，肝脏生物钟中Per1和Per2的重新同步比其他四个生物钟基因更快，表明这两个生物钟基因在启动肝脏生物钟的昼夜重设中起重要作用。然而，这两个生物钟基因在心脏生物钟中的重设速率与其他基因相似。因此，这两个外周生物钟的重设机制可能完全不同。此外，与黑暗周期转换相比，通过光照周期转换进行喂食和LD颠倒后，肝脏和心脏生物钟的重新同步相对延长，表明喂食时间表和LD周期的同时改变可能有助于大鼠的昼夜重设。
