Department of Physiology, Wakayama Medical University School of Medicine, Japan.
Endocr J. 2012;59(6):447-56. doi: 10.1507/endocrj.ej12-0057. Epub 2012 Feb 24.
Understanding how the 24-hour blood-pressure rhythm is programmed has been one of the most challenging questions in cardiovascular research. The 24-hour blood-pressure rhythm is primarily driven by the circadian clock system, in which the master circadian pacemaker within the suprachiasmatic nuclei of the hypothalamus is first entrained to the light/dark cycle and then transmits synchronizing signals to the peripheral clocks common to most tissues, including the heart and blood vessels. However, the circadian system is more complex than this basic hierarchical structure, as indicated by the discovery that peripheral clocks are either influenced to some degree or fully driven by temporal changes in energy homeostasis, independent of the light entrainment pathway. Through various comparative genomic approaches and through studies exploiting mouse genetics and transgenics, we now appreciate that cardiovascular tissues possess a large number of metabolic genes whose expression cycle and reciprocally affect the transcriptional control of major circadian clock genes. These findings indicate that metabolic cycles can directly or indirectly affect the diurnal rhythm of cardiovascular function. Here, we discuss a framework for understanding how the 24-hour blood-pressure rhythm is driven by the circadian system that integrates cardiovascular and metabolic function.
理解 24 小时血压节律是如何编程的一直是心血管研究中最具挑战性的问题之一。24 小时血压节律主要由昼夜节律钟系统驱动，其中下丘脑视交叉上核中的主昼夜节律起搏器首先与光/暗周期同步，然后将同步信号传递到包括心脏和血管在内的大多数组织中常见的外周时钟。然而，昼夜节律系统比这种基本的层次结构更为复杂，这一点可以通过发现来证明，即外周时钟在一定程度上受到能量平衡的时间变化的影响，而不受光同步途径的影响。通过各种比较基因组方法以及利用小鼠遗传学和转基因技术进行的研究，我们现在认识到心血管组织拥有大量代谢基因，其表达周期相互影响主要昼夜节律钟基因的转录控制。这些发现表明，代谢周期可以直接或间接地影响心血管功能的昼夜节律。在这里，我们讨论了一个理解昼夜节律系统如何驱动 24 小时血压节律的框架，该框架整合了心血管和代谢功能。
