Department of Animal Physiology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35043 Marburg, Germany.
J Comp Physiol B. 2013 May;183(4):567-81. doi: 10.1007/s00360-012-0721-4. Epub 2012 Dec 2.
Golden spiny mice (Acomys russatus) living in the Judean desert are exposed to extended periods of food and water shortage. We investigated their thermal and metabolic response to three weeks of 50% food reduction at ambient temperatures of 23, 27, 32 and 35 °C by long term records of metabolic rate and body temperature in the laboratory. At all ambient temperatures, A. russatus responded to starvation by a reduction of daily energy expenditure. At 32 and 35 °C, this metabolic adjustment fully compensated the reduced food availability and they maintained their energy balance at a slightly reduced body mass. At lower ambient temperatures, they could not fully compensate for the reduced food availability and kept a negative energy balance. The reduction of daily energy expenditure was largely achieved by the occurrence of daily torpor. Torpor even occurred at high ambient temperatures of 32 and 35 °C during which metabolic depression was not associated with a marked decrease of body temperature. The results show that the occurrence of daily torpor is not necessarily linked to cold exposure and the development of a pronounced hypothermia, but may even occur as depression of metabolic rate in a hot environment.
生活在朱迪亚沙漠的金黄沙鼠（Acomys russatus）会经历长时间的食物和水短缺。我们通过在实验室中对代谢率和体温进行长期记录，研究了它们在 23、27、32 和 35°C 的环境温度下，对 50%食物减少的 3 周适应过程中的热和代谢反应。在所有环境温度下，金黄沙鼠通过减少每日能量消耗来应对饥饿。在 32 和 35°C 时，这种代谢调整完全补偿了食物供应的减少，它们在略微降低的体重下维持能量平衡。在较低的环境温度下，它们无法完全补偿食物供应的减少，保持负的能量平衡。每日休眠在很大程度上实现了每日能量消耗的减少。即使在 32 和 35°C 的高温环境下也会发生休眠，而此时代谢抑制与体温明显下降无关。结果表明，每日休眠的发生不一定与寒冷暴露和明显的体温下降有关，甚至可能在炎热的环境中发生代谢率降低的情况。
