Abstract: Four experiments were designed to investigate the influence of photoperiod and ambient temperature on body
weight, body temperature,resting oxygen consumption (RMR),nonshivering thermogenesis (NST_max)and cellular biochemistry in Eothenomys miletus. Eothenomys miletus were acclimated to the following conditions for 28 days:1 ) long days and warm (30-LP)(30 ± 1℃ ,18L∶ 6D), 2) long days and cold (5-LP) (5 ± 1℃ ,18L∶ 6D), 3) short days and
warm (30-SP)(30 ± 1℃,6L∶ 18D), 4) short days and cold (5-SP)(5 ± 1℃ ,6L∶ 18D). The results showed that
temperature was the more important environmental factor for variations of thermogenesis in Eothenomys miletus. In both photoperiods, body weight,body temperature, RMR and NSTmax were significantly modified by ambient temperatures. Exposure to ambient temperatures at 5 ±1℃ was associated with a decrease in body weight,body temperature and an increase in RMR and NSTmax,Heat exposure caused an increase in body temperature and an decrease in RMR and NSTmax. The low temperature could induce an increase in Liver/BAT protein contents, mitochondrial state-3 and state-4 respiration,α-glycerophosphate oxidase of Liver/ BAT mitochondria, and cytochrome C oxidase activity of Liver / BAT mitochondria. A warm ambient temperature induced opposite phenomena. But there were no significant differences between long days and short days. Thermoregulatory responses to changes in ambient temperature were not significantly altered by day length. It seemed
that Eothenomys miletus were more sensitive to temperature.

Key words: Adaptive thermogenesis, Ambient temperature, Eothenomys miletus, Photoperiod

摘要： 为了解横断山地区大绒鼠对光照和温度两个因子的适应性特征,将大绒鼠分为4 组,分别于5 ± 1℃,6L∶18D; 5 ± 1℃,18L∶ 6D; 30 ± 1℃,6L∶ 18D 和30 ± 1℃ ,18L∶ 6D 4 个条件下驯化28 d。分别测定了对照组(0 d)和驯化28 d 后,每一个体的体重、体温和产热能力;并测定驯化28 d 后4 组大绒鼠个体的肝脏和褐色脂肪组织的产热活性变化。结果显示,在低温诱导下大绒鼠体重下降,体温降低,静止代谢率升高,非颤抖性产热能力增加,肝脏和褐色脂肪组织的产热活性也出现相应提升;在高温下出现与低温时相反的现象;但光照周期对大绒鼠的体重、体温、产热能力及肝脏和褐色脂肪组织的产热活性均没有显著影响。推测由于横断山的低纬度、高海拔特征可能导致大绒鼠在季节适应过程中对温度的敏感程度高于光照。