通过食来训练肝脏的昼夜时钟
K A Stokkan1, S Yamazaki, H Tei
1National Science Foundation Center for Biological Timing and Department of Biology, University of Virginia, P.O. Box 400328, Charlottesville, VA 22904-4328, USA. mm7e@virginia.edu
Science (New York, N.Y.)
|February 13, 2001
概括
限制饮食迅速改变了肝脏的基因表达节奏,独立于大脑的主钟 (上性核). 这挑战了关于昼夜等级的传统观点,并表明养行为可能会将外围时钟与SCN联系起来.
科学领域:
- 时间生物学 时间生物学
- 分子生物学分子生物学
- 身体生理学 身体生理学
背景情况:
- 循环节律控制着生物过程,通过上神核 (SCN) 通过光暗周期同步.
- 外围器官表现出昼夜基因表达节奏,但它们与中央SCN时钟的协调仍然不完全理解.
- 非光学线索 (如食时间表) 对外围昼夜组织的影响是研究的一个关键领域.
研究的目的:
- 调查限制养时间表如何影响外周组织 (肝脏,肺) 和中央SCN的昼夜基因表达节奏.
- 通过从SCN和光暗周期输入线索来确定外围时钟引进的独立性.
- 重新评估哺乳动物昼夜系统的等级组织.
主要方法:
- 利用表达 luciferase 的转基因大鼠模型在体外监测昼夜节律.
- 在受控的光暗和受限制的养条件下,在肝脏,肺部和SCN中比较基因表达节奏.
- 在周围和中心的昼夜振荡器中,量化相位的变化是响应于养引进的反应.
主要成果:
- 在SCN中,循环节律保持与光暗周期同步.
- 限制饮食迅速引入肝脏的昼夜节律,导致2天内大约10小时的相位转移.
- 肺部昼夜节律也显示了食时间表的显著影响,尽管转变的程度没有详细说明.
结论:
- 养周期可以独立地引入外围昼夜振荡器,如肝脏,无论SCN和光暗周期.
- 这些发现挑战了已建立的哺乳动物昼夜层次结构,表明中央和外围时钟之间更复杂的相互作用.
- 节律性行为,包括食,可以作为连接外围昼夜振荡器与SCN的主要机制.
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