Graduate Group in Endocrinology, University of California, Berkeley, California, USA.
Department of Psychology, University of California, Berkeley, California, USA.
Compr Physiol. 2022 Sep 8;12(4):4185-4214. doi: 10.1002/cphy.c220018.
Circadian rhythms are endogenously generated, daily patterns of behavior and physiology that are essential for optimal health and disease prevention. Disruptions to circadian timing are associated with a host of maladies, including metabolic disease and obesity, diabetes, heart disease, cancer, and mental health disturbances. The circadian timing system is hierarchically organized, with a master circadian clock located in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus and subordinate clocks throughout the CNS and periphery. The SCN receives light information via a direct retinal pathway, synchronizing the master clock to environmental time. At the cellular level, circadian rhythms are ubiquitous, with rhythms generated by interlocking, autoregulatory transcription-translation feedback loops. At the level of the SCN, tight cellular coupling maintains rhythms even in the absence of environmental input. The SCN, in turn, communicates timing information via the autonomic nervous system and hormonal signaling. This signaling couples individual cellular oscillators at the tissue level in extra-SCN brain loci and the periphery and synchronizes subordinate clocks to external time. In the modern world, circadian disruption is widespread due to limited exposure to sunlight during the day, exposure to artificial light at night, and widespread use of light-emitting electronic devices, likely contributing to an increase in the prevalence, and the progression, of a host of disease states. The present overview focuses on the circadian control of endocrine secretions, the significance of rhythms within key endocrine axes for typical, homeostatic functioning, and implications for health and disease when dysregulated. © 2022 American Physiological Society. Compr Physiol 12: 1-30, 2022.
昼夜节律是内源性产生的、每日的行为和生理模式，对最佳健康和疾病预防至关重要。昼夜节律的破坏与许多疾病有关，包括代谢疾病和肥胖、糖尿病、心脏病、癌症和心理健康障碍。昼夜节律计时系统是分层组织的，主生物钟位于下丘脑前视交叉上核 (SCN)，从属生物钟分布于中枢神经系统和外周。SCN 通过直接视网膜途径接收光信息，使主时钟与环境时间同步。在细胞水平上，昼夜节律无处不在，由相互交错的、自我调节的转录-翻译反馈环产生。在 SCN 水平上，紧密的细胞耦合即使在没有环境输入的情况下也能维持节律。反过来，SCN 通过自主神经系统和激素信号传递时间信息。这种信号在组织水平上在 SCN 以外的脑区和外周将个体细胞振荡器耦合，并使从属生物钟与外部时间同步。在现代世界，由于白天暴露在阳光下的时间有限、夜间暴露在人造光下以及广泛使用发光电子设备，昼夜节律的破坏很普遍，可能导致许多疾病状态的流行率和进展率增加。本综述重点介绍内分泌分泌的昼夜节律控制，关键内分泌轴内节律对典型的、稳态功能的重要性，以及失调时对健康和疾病的影响。© 2022 美国生理学会。综合生理学 12:1-30,2022。
