Smith C K, Romsos D R
Metabolism. 1984 Sep;33(9):853-7. doi: 10.1016/0026-0495(84)90114-8.
Obese (ob/ob) and lean mice at 4 weeks of age were housed at 23 degrees C or 14 degrees C for 4 to 8 weeks to examine effects of acclimation to mild cold on energy balance. Energy intake of young lean mice increased by about 50% when housed at 14 degrees C, but energy intake of cold-acclimated obese mice increased by only 8%. Efficiency of energy retention (ratio of energy gain to energy intake) in obese mice declined from 22% +/- 1.2% at 23 degrees C to 10% +/- 1.8% after 4 weeks at 14 degrees C. Lean mice exhibited a less pronounced response to temperature; their efficiency of energy retention declined from 7% +/- 1.3% at 23 degrees C to 4% +/- 2.2% after 4 weeks at 14 degrees C. After 8 weeks of cold exposure, body weights and efficiency of energy retention became equal in obese and lean mice. Calculated heat production of cold-acclimated obese and lean mice was 40% higher than that of respective controls. Obese mice reacclimated to 23 degrees C after being kept for 4 weeks at 14 degrees C consumed the same amount of energy and were 16% more efficient than obese maintained at 23 degrees C; reacclimated lean mice consumed 12% more energy but were 53% less efficient than lean mice maintained at 23 degrees C. The results indicate that obese mice are able to increase heat production and markedly reduce their efficiency of energy retention when acclimated to mild cold but that they, unlike lean mice, rapidly revert to a high efficiency of energy retention after 4 weeks of reacclimation to 23 degrees C.
将4周龄的肥胖（ob/ob）小鼠和瘦小鼠分别置于23摄氏度或14摄氏度环境中饲养4至8周，以研究适应轻度寒冷对能量平衡的影响。饲养在14摄氏度环境中的年轻瘦小鼠能量摄入量增加了约50%，但适应寒冷环境的肥胖小鼠能量摄入量仅增加了8%。肥胖小鼠的能量保留效率（能量增加量与能量摄入量之比）从23摄氏度时的22%±1.2%下降到14摄氏度环境中4周后的10%±1.8%。瘦小鼠对温度的反应不太明显；它们的能量保留效率从23摄氏度时的7%±1.3%下降到14摄氏度环境中4周后的4%±2.2%。经过8周的寒冷暴露后，肥胖小鼠和瘦小鼠的体重及能量保留效率变得相等。适应寒冷环境的肥胖小鼠和瘦小鼠的计算产热量比各自的对照组高40%。在14摄氏度环境中饲养4周后再适应到23摄氏度的肥胖小鼠消耗的能量相同，且比一直饲养在23摄氏度的肥胖小鼠效率高16%；再适应的瘦小鼠消耗的能量多12%，但比一直饲养在23摄氏度的瘦小鼠效率低53%。结果表明，肥胖小鼠在适应轻度寒冷时能够增加产热并显著降低其能量保留效率，但与瘦小鼠不同的是，在再适应23摄氏度4周后，它们会迅速恢复到较高的能量保留效率。
