关键词: 大绒鼠, 产热, 体温调节

Abstract: The oriental voles (Eothenomys miletus)is a typical species inhabiting Hengduan mountains region of Yunnan Province. In our paper，we interested in the characteristics of thermoregulation, including the feathers of heat production at individual level, the biochemical mechanisms in liver and brown adipose tissue (BAT).The body temperature (T_b) at room temperature(16.0-24.8℃) was 35.9±0.37℃(N=99), Its T_b was on1y stable in 15-30℃ approximately. When the ambient temperature reached 32.5℃, the animals were hyperthermal obviously. The thermal neutral zone (TNZ) was from 25℃ to30℃, and the minimum resting metabolic rate (BMR) was 2.71±0.18 ml O₂/ g. h, which was 213. 2±10.3% of previous predicted body mass. At the ambient temperature below 27.5℃, there was a negative relationship between RMR and T_a，which was be described: RMR= 6.473–0.145 T_a ( T_a : 5-27. 5℃;r=-0.848, P<0.001;N = 74). The average minimum thermal conductance(Cm)was 0.23士0.01 ml O₂/ g. h. ℃,which was 141.7±0.6% of previous predicted by body mass. When the T_a was below 30℃, Cm increased slowly with T_a increasing, and the relationship of Cm and T_a was as follows: Cm =0. 1219±0.0078T_a (T_a: 5-27.5℃;r=–0.7216;P < 0. 0001，N = 74). When T_a was above 30℃, Cm increased strikingly. The consumption of oxygen induced by noradrenaline(NE) injected was 5.18±0.01 ml O₂/ g. h (N=11;T_a=25 ℃.The liver mass was 2.11±0.25 g, Liver/ BW×100% was 5.3%(N=11), the total and mitochondrial protein content were 76±3.8 and 20. 5±1.9 mg/g, respectively. The activity of cytochrome C oxidase(COX) in mitochondria was 88.5±8.4 (ng O atom/ mg mit. protein min).The BAT mass was 0.33±0.05 g BAT/BW×100% was 0.84%(N=11)，the total and mitochondrial protein content were 31.5士1.4 and 18.8±0.05 mg/g respectively; The activity of cytochrome C oxidase(COX) in mitochondria was 1731.6±146 (ng O atom/ mg mit. protein min).The mitochondrial respirations of state Ⅳ was 76.43±1.6(ng O atom/ mg mit. protein min).In conclusion that the high level of RMR and NSTmax in the voles were related with adapting to altitude environments; the thermogenical capacity of liver was the main factor resulting in its RMR increasing.

Key words: Oriental vole (Eothenomys miletus), Thermogenesis, RMR, NSTmax