Talan M I, Engel B T, Whitaker J R
J Gerontol. 1985 Jan;40(1):8-14. doi: 10.1093/geronj/40.1.8.
C57BL/6J male mice of different ages were movement-restricted and exposed to 10 degrees C for 3-hr periods every other week while colonic temperature was measured. A longitudinal trend in cold tolerance related to age and to initial colonic temperature was demonstrated. Adaptative thermoregulatory changes during cold exposure occurred during the first two tests. These were similar for all age groups except 30-month-old mice. There was no adaptation of colonic temperature during cold exposure among aged mice with repeated testing; however, their baseline colonic temperatures prior to testing increased after the first two tests. This finding suggests that old animals adjust to repeated cold stress differently than do younger mice. Specifically, younger animals are capable of adjusting their thermoregulatory response during cold stress with no change in baseline (pre-stress) temperature. Old animals do not modify the responses emitted during the stress; however, they do adapt by raising their baseline temperatures. Repeated cold exposure started later in life increased mortality among old animals but did not affect maximum lifespan.
对不同年龄的C57BL/6J雄性小鼠进行运动限制，每隔一周将其暴露于10摄氏度环境中3小时，同时测量结肠温度。结果显示出与年龄和初始结肠温度相关的耐寒性纵向趋势。在最初的两次测试中，冷暴露期间出现了适应性体温调节变化。除30月龄小鼠外，所有年龄组的情况均相似。在重复测试中，老年小鼠在冷暴露期间结肠温度没有适应性变化；然而，在最初的两次测试后，它们测试前的基线结肠温度升高了。这一发现表明，老年动物与年轻小鼠对反复冷应激的适应方式不同。具体而言，年轻动物能够在冷应激期间调节其体温调节反应，而基线（应激前）温度不变。老年动物不会改变应激期间的反应；然而，它们会通过提高基线温度来适应。在生命后期开始的反复冷暴露会增加老年动物的死亡率，但不会影响最大寿命。
