Scheving L E, Tsai T H, Scheving L A
Am J Anat. 1983 Dec;168(4):433-65. doi: 10.1002/aja.1001680405.
This paper summarizes recent and continuing work on circadian rhythms in the alimentary tract of rodents; these include: (1) cell proliferation, (2) activities of intestinal enzymes, and (3) behavioral aspects of spontaneous feeding and drinking. All regions of the intestinal tract show marked circadian behavior in cell proliferation. The roles of the light-dark cycle and meal timing in synchronizing such rhythms are discussed as well as the influence of epidermal growth factor, insulin, glucagon, and ACTH 1-17. Attention is called to the potential importance of these rhythms to basic research and medicine. Other circadian rhythms in the alimentary tract are reviewed briefly, such as those characterizing a host of intestinal enzymes, monosaccharide transport, and the height and width of the villi. Many of these have been shown to be cued to a feeding schedule; however, a number of the enzyme rhythms persist for one or two cycles in fasting animals, and this also is the case for the cell-proliferation rhythms. After having been acclimated to a circadian feeding schedule (within a range of 23-30 hr), rodents can on subsequent days anticipate the food an hour or more prior to its arrival. Some enzymes behave in a similar manner in that their activities increase prior to the expected intake of the daily food. These anticipatory response rhythms are under endogenous control, since both will persist in the fasted animal and both will free run when a mouse is placed under constant conditions. Somehow these animals are able to measure circadian intervals of time. This challenges the concept that the oscillations seen in enzyme activities are simply a passive consequence of feeding and fasting, respectively.
本文总结了近期以及正在进行的关于啮齿动物消化道昼夜节律的研究工作；这些研究包括：（1）细胞增殖，（2）肠道酶的活性，以及（3）自发进食和饮水的行为方面。肠道的所有区域在细胞增殖方面均表现出明显的昼夜节律行为。文中讨论了明暗周期和进食时间在同步此类节律中的作用，以及表皮生长因子、胰岛素、胰高血糖素和促肾上腺皮质激素1 - 17的影响。文中还指出了这些节律对基础研究和医学的潜在重要性。本文还简要回顾了消化道中的其他昼夜节律，例如许多肠道酶、单糖转运以及绒毛高度和宽度所具有的昼夜节律特征。其中许多已被证明与进食时间表有关；然而，一些酶的节律在禁食动物中会持续一到两个周期，细胞增殖节律也是如此。在适应了昼夜进食时间表（在23 - 30小时范围内）后，啮齿动物在随后的日子里能够在食物到达前一小时或更长时间预测到食物。一些酶的行为方式类似，它们的活性在预期的每日食物摄入之前就会增加。这些预期反应节律受内源性控制，因为它们在禁食动物中都会持续存在，并且当小鼠处于恒定条件下时都会自由运转。不知何故，这些动物能够测量昼夜时间间隔。这对酶活性波动仅仅分别是进食和禁食的被动结果这一概念提出了挑战。
