Leung P M, Horwitz B A
Am J Physiol. 1976 Oct;231(4):1220-4. doi: 10.1152/ajplegacy.1976.231.4.1220.
Four adult Sprague-Dawley rats (430-450 g), maintained on a 12:12 h dark/light cycle and 15% casein diet, were exposed to cold (5 degrees C) for 77 days and then transferred back to 24 degrees C. Throughout thisperiod, the feeding patterns of the rats were measured with recording balances. Cold exposure caused an immediate reduction in nocturnal meal frequency that remained low during the cold exposure. In contrast, diurnal meal frequency was unaltered. Average nocturnal meal size, which did not significantly increase before 8 days of cold, reached a plateau in 2 wk, whereas the average diurnal meal size did not significantly change until late in the exposure period. "Warm" (24 degrees C) reentry elicited an abrupt increase in nocturnal meal frequency and a reduction in average nocturnal as well as diurnal meal size. It thus appears that even in the face of a sudden increase in energy expenditure resulting from cold exposure, adult rats do not immediately adjust their daily food intake. On the other hand, the adaptive hyperphagic response occurring after cold acclimation is abolished when the energy demand is eliminated, i.e., when the animals are removed from the cold.
四只成年斯普拉格-道利大鼠（体重430-450克），饲养于12:12小时明暗循环和15%酪蛋白饮食条件下，暴露于低温（5摄氏度）环境77天，然后转移回24摄氏度环境。在此期间，用记录天平测量大鼠的进食模式。冷暴露导致夜间进食频率立即降低，在冷暴露期间一直保持在较低水平。相比之下，白天进食频率未改变。冷暴露8天前平均夜间进食量未显著增加，2周时达到平稳状态，而平均白天进食量直到暴露后期才出现显著变化。“温暖”（24摄氏度）环境再适应引发夜间进食频率突然增加，同时平均夜间和白天进食量减少。因此，即使面对冷暴露导致的能量消耗突然增加，成年大鼠也不会立即调整其每日食物摄入量。另一方面，当能量需求消除时，即动物从寒冷环境中移出时，冷适应后出现的适应性多食反应就会消失。
