【摘要】 为了解小毛足鼠对沙漠生境的适应特征,对其能量代谢和体温调节特征进行了测定。代谢率采用封闭式流体压力呼吸计测定,非颤抖性产热用皮下注射去甲肾上腺素诱导,能量摄入采用食物平衡法测定。结果显示:小毛足鼠的热中性区为25～33℃,平均体温为35 7±0 1℃,最小热传导率为0 21±0 01mlO2/g·h·℃,基础代谢率为2 61±0 04mlO2/g·h,最大非颤抖性产热为8 53±0 28mlO2/g·h,非颤抖性产热范围(最大非颤抖性产热与基础代谢率的比率)为3 3。基础代谢率和非颤抖性产热都高于以体重为基础的期望值,最小热传导接近期望值。小毛足鼠的摄入能为2 26±0 12kJ/g·d;消化能为2 18±0 13kJ/g·d;消化率为97±0 2%;可代谢能为2 13±0 12kJ/g·d;可代谢能效率为94±1 2%。这些结果表明小毛足鼠对沙地生境的适应特征是:基础代谢率较高,体温相对较低,最小热传导率与期望值相当,热中性区较宽,下临界温度较低;较高的最大非颤抖性产热和非颤抖性产热范围以及较高的食物消化效率。更多还原

【Abstract】 In order to understand the adaptive ecophysiological characteristics of desert hamsters(Phodopus roborovskii)lived in Hunshandake desert of Inner Mongolia,we measured the energy metabolism and thermoregulation of adult hamsters. Metabolic rates were measured at a temperature range from 7 to 35℃ using the closed-circuit respirometer,and the nonshivering thermogenesis was induced by subcutaneous injection of norepinephrine. The energy intakes were estimated with food trials. The body masses and body temperatures of animals were measured before and after each experiment. The thermal neutral zone (TNZ) of desert hamsters was 25 to 33℃,basal metabolic rate (BMR) was 2.61±0.04(mlO2/g·h),which is 152% and 180% of the values predicted by Hayssen & Lacy (1985) and McNab (1988) based on body mass,respectively. Mean body temperature of desert hamsters at the temperature range of 7 to 31℃ was 35.7±0.1℃. The minimum thermal conductance within the temperature range of 7 to 25℃ was 0.21(mlO2/g·h·℃),which is 98% of that predicted by Bradley & Deavers (1980). The maximum nonshivering thermogenesis of desert hamsters was 8.53±0.28 mlO2/g·h,which is 114% of the value predicted by Heldmaier (1971) based on body mass,and the nonshivering thermogenesis scope (ratio of maximum NST to BMR)was 3.3. The energy intake,digested energy,and metabolizable energy intake was 2.26±0.12 kJ/g·d,2.18±0.13 kJ/g·d,and 2.13±0.12 kJ/g·d,respectively,while the digestibility and metabolizable energy efficiency was 97±0.2%and 94±1.2%,respectively. Digestibility is higher in desert hamsters than other rodent species. No significant relationship between basal metabolic rate and digested energy was detected and,however,there was a significant relationship between minimum thermal conductance and energy intake, digested energy, and metabolizable energy intake. These results suggest that high BMR and NST, wider TNZ, lower low critical temperature, relative lower body temperature, thermal conductance equal to the predicted value, and high digestibility can enable desert hamsters to live in an arid environment with high fluctuations in environment temperature and food resources.更多还原