a Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas , Instituto Politécnico Nacional , Ciudad de México , Mexico.
b División de Neurociencias, Instituto de Fisiología Celular , UNAM , Ciudad de México , Mexico.
Chronobiol Int. 2018 Nov;35(12):1680-1688. doi: 10.1080/07420528.2018.1507036. Epub 2018 Aug 10.
Eating behavior is controlled by the energy needs of the organism. The need to provide a constant supply of energy to tissues is a homeostatic drive that adjusts feeding behavior to the energetic condition of the organism. On the other hand, food intake also shows a circadian variation synchronized to the light-dark cycle and food availability. Thus, feeding is subjected to both homeostatic and circadian regulation mechanisms that determine the amount and timing of spontaneous food intake in normal conditions. In the present study we contrasted the influence of the homeostatic versus the chronostatic mechanisms on food intake in normal conditions and in response to fasting. A group of rats was subjected to food deprivation under two different temporal schemes. A constant-length 24-h food deprivation started at different times of day resulted in an increased compensatory intake. This compensatory response showed a circadian variation that resembled the rhythm of intake in non-deprived animals. When subjected to fasting periods of increasing length (24-66 h), the amount of compensatory feeding varied according to the time of day in which food was made available, being significantly less when the fast ended in the middle of the light phase or beginning of the dark phase. These oscillatory changes did not have a correlation with variations in the level of glucose or β-hydroxybutyrate in the blood. The results suggest that the mechanism of homeostatic compensation is modulated chronostatically, presumably as part of the alternation of catabolic and anabolic states matching the daily cycles of activity.
进食行为受机体能量需求的控制。为组织提供持续能量供应的需求是一种体内平衡驱动，它会根据机体的能量状态来调整进食行为。另一方面，食物摄入也表现出与光-暗周期和食物供应同步的昼夜节律变化。因此，进食受到体内平衡和昼夜节律调节机制的双重控制，这些机制决定了正常条件下自发食物摄入的量和时间。在本研究中，我们对比了体内平衡机制和时间同步机制对正常条件下和禁食反应中食物摄入的影响。一组大鼠在两种不同的时间方案下进行了食物剥夺。在一天中的不同时间开始的持续 24 小时的食物剥夺导致了代偿性进食的增加。这种代偿性反应表现出昼夜节律变化，类似于未剥夺动物的摄入节律。当进行时长逐渐增加的禁食期（24-66 小时）时，代偿性进食的量根据提供食物的时间而变化，当禁食在光相中期或暗相开始时结束时，代偿性进食显著减少。这些波动变化与血液中葡萄糖或β-羟丁酸水平的变化没有相关性。研究结果表明，体内平衡补偿的机制受到时间同步的调节，可能是适应活动的每日周期的分解代谢和合成代谢状态交替的一部分。
