Leal A M, Moreira A C
Divisão de Endocrinologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.
Braz J Med Biol Res. 1997 Dec;30(12):1391-405. doi: 10.1590/s0100-879x1997001200003.
Temporal organization is an important feature of biological systems and its main function is to facilitate adaptation of the organism to the environment. The daily variation of biological variables arises from an internal time-keeping system. The major action of the environment is to synchronize the internal clock to a period of exactly 24 h. The light-dark cycle, food ingestion, barometric pressure, acoustic stimuli, scents and social cues have been mentioned as synchronizers or "zeitgebers". The circadian rhythmicity of plasma corticosteroids has been well characterized in man and in rats and evidence has been accumulated showing daily rhythmicity at every level of the hypothalamic-pituitary-adrenal (HPA) axis. Studies of restricted feeding in rats are of considerable importance because they reveal feeding as a major synchronizer of rhythms in HPA axis activity. The daily variation of the HPA axis stress response appears to be closely related to food intake as well as to basal activity. In humans, the association of feeding and HPA axis activity has been studied under physiological and pathological conditions such as anorexia nervosa, bulimia, malnutrition, obesity, diabetes mellitus and Cushing's syndrome. Complex neuroanatomical pathways and neurochemical circuitry are involved in feeding-associated HPA axis modulation. In the present review we focus on the interaction among HPA axis rhythmicity, food ingestion, and different nutritional and endocrine states.
时间组织是生物系统的一个重要特征，其主要功能是促进生物体适应环境。生物变量的每日变化源自内部计时系统。环境的主要作用是将内部时钟同步到恰好24小时的周期。明暗周期、食物摄入、气压、声刺激、气味和社会线索已被提及为同步器或“授时因子”。血浆皮质类固醇的昼夜节律在人类和大鼠中已得到充分表征，并且已有证据表明下丘脑-垂体-肾上腺（HPA）轴的各个水平都存在每日节律。对大鼠限食的研究具有相当重要的意义，因为它们揭示了进食是HPA轴活动节律的主要同步器。HPA轴应激反应的每日变化似乎与食物摄入以及基础活动密切相关。在人类中，已在诸如神经性厌食症、贪食症、营养不良、肥胖症、糖尿病和库欣综合征等生理和病理条件下研究了进食与HPA轴活动的关联。复杂的神经解剖学通路和神经化学回路参与了与进食相关的HPA轴调节。在本综述中，我们重点关注HPA轴节律性、食物摄入以及不同营养和内分泌状态之间的相互作用。
