Turek F W
Department of Neurobiology and Physiology Northwestern University, Evanston, Illinois 60208.
Recent Prog Horm Res. 1994;49:43-90. doi: 10.1016/b978-0-12-571149-4.50007-6.
Changes in behavior which occur on a daily or circadian basis represent one of the most ubiquitous strategies by which most living organisms have adapted to their environment. Underlying the daily changes in behavior are a multitude of endocrine and metabolic rhythms which provide adaptively significant temporal organization within the organism. In mammals there appears to be a central circadian clock in the SCN which is responsible for generating and coordinating the entire 24-hour temporal organization of the animal. The circadian clock regulates the timing, duration, and characteristics of sleep, and together the circadian clock and sleep interact to control the timing of endocrine secretions. While the impact of disturbed endocrine circadian rhythms for the survival of the species has received very little attention, the almost universal presence of circadian rhythmicity within the endocrine system argues in support of the hypothesis that a disruption of the normal circadian organization within the endocrine system can have serious consequences for the health and well-being of the organism. It is particularly noteworthy that in advanced age, various alterations in circadian endocrine rhythms have been observed and these alterations may impair the ability of the animal to adapt normally to the environment. Relatively speaking, the study of circadian rhythms is a new field of biology, and as a result, much remains to be discovered about the physiological mechanisms that underlie rhythmicity, as well as the functional significance of 24-hour temporal organization for the survival of the species.
每日或昼夜节律性发生的行为变化是大多数生物适应环境的最普遍策略之一。行为的日常变化背后是众多的内分泌和代谢节律，它们在生物体内提供具有适应性重要意义的时间组织。在哺乳动物中，视交叉上核似乎存在一个中央昼夜节律时钟，它负责产生和协调动物整个24小时的时间组织。昼夜节律时钟调节睡眠的时间、持续时间和特征，并且昼夜节律时钟和睡眠相互作用以控制内分泌分泌的时间。虽然内分泌昼夜节律紊乱对物种生存的影响很少受到关注，但内分泌系统中几乎普遍存在昼夜节律性，这支持了这样一种假设，即内分泌系统内正常昼夜节律组织的破坏可能对生物体的健康和福祉产生严重后果。特别值得注意的是，在老年时，已观察到昼夜内分泌节律的各种改变，这些改变可能损害动物正常适应环境的能力。相对而言，昼夜节律的研究是生物学的一个新领域，因此，关于节律性背后的生理机制以及24小时时间组织对物种生存的功能意义，仍有许多有待发现。
