German E, Hoffman-Goetz L
J Gerontol. 1986 Jul;41(4):453-9. doi: 10.1093/geronj/41.4.453.
We investigated whether intermittent cold acclimation and low intensity exercise training, two interventions known to improve thermoregulatory function in young rodents, enhanced cold tolerance in aged C57BL/6J mice. Mice, aged 18 to 20 months, were randomly assigned to four treatment conditions: (a) intermittent cold acclimation (CA) (50 min per day, 5 times per week for 3 weeks at 5 degrees C), (b) submaximal treadmill exercise (EX) (15 m min-1 for 30 min, 5 times per week for 8 weeks, (c) sequential treatment of CA + EX, and (d) control group. Mice were exposed to a 3-hr cold stress test (15 degrees C) prior to and following treatment. CA aged mice maintained normothermia and demonstrated significant increases in oxygen consumption and brown adipose tissue protein concentration compared with controls; enhanced cold tolerance was probably due to increased utilization of nonshivering thermogenesis. EX aged mice had elevated O2 consumption and increased skeletal muscle enzyme activity compared with controls; however, cold tolerance was not enhanced compared with CA mice. The data suggest that intermittent CA effectively reduces hypothermia during cold challenge in aged mice.
我们研究了间歇性冷适应和低强度运动训练这两种已知可改善幼龄啮齿动物体温调节功能的干预措施，是否能增强老年C57BL/6J小鼠的耐寒能力。将18至20个月龄的小鼠随机分为四种处理组：(a)间歇性冷适应(CA)(每天50分钟，每周5次，在5摄氏度下进行3周)，(b)次最大强度跑步机运动(EX)(15米/分钟，持续30分钟，每周5次，共8周)，(c) CA + EX序贯处理，以及(d)对照组。在处理前后，让小鼠接受3小时的冷应激测试(15摄氏度)。与对照组相比，CA老年小鼠维持了正常体温，耗氧量和棕色脂肪组织蛋白浓度显著增加；耐寒能力增强可能是由于非寒战产热的利用率增加。与对照组相比，EX老年小鼠的耗氧量升高，骨骼肌酶活性增加；然而，与CA小鼠相比，其耐寒能力并未增强。数据表明，间歇性CA能有效降低老年小鼠在冷刺激期间的体温过低情况。
