【摘要】 为探讨寒冷地区黑线仓鼠 (Cricetulusbarabensis)的代谢产热特征及体温调节 ,本文采用封闭式流体压力呼吸仪对其代谢率、热传导和体温等热生物学指标进行了测定。结果显示 :在环境温度为 5～ 35℃的范围内 ,黑线仓鼠的体温基本维持恒定 ,平均体温为 36 33± 0 2 3℃ ;热中性区为 2 5～ 32 5℃ ;基础代谢率为 3 4 9±0 36mlO2 / (g·h) ;环境温度 (Ta)在 5～ 2 5℃范围内 ,代谢率 (MR)与Ta 呈负相关 ,回归方程为 :MR [mlO2 / (g·h) ]=9 6 0 - 0 2 2Ta (℃ ) ,在此范围内 ,黑线仓鼠的热传导率 (C)最低 ,平均为 0 2 8± 0 0 1mlO2 /(g·h·℃ ) ;代谢预期比和热传导预期比 (F值 )为 1 6 8。黑线仓鼠的基本热生物学特征为 :较高的BMR和热传导率 ,相对较低的体温和较宽的热中性区。这些特征可能限制了其在极端寒冷和干旱环境中的分布和生存.更多还原

【Abstract】 In order to understand the ecophysiological characteristics of the striped hamster(Cricetulus barabensis) inhabiting in relative cold area, we measured their metabolic rates, body temperatures(T b), and thermal conductance at a temperature range of 5-35℃. Adult striped hamsters were live-trapped in the farmland of Qiqihar City of Heilongjiang Province from April to June 1997. Eight animals(five males and three females)were used in this experiment. Their mean body mass was 20 90±3 12 g(mean±SE). Animals were kept in large cages under natural photoperiod and temperature, and fed laboratory ‘rat chow’ pellets for about a week. Food and water were supplied ad lib. We measured the metabolic rate using a closed circuit respirometer, meanwhile we measured the temperature inside the animal chambers(size=3 6 L), and maintained the temperature with a constant water bath(±0 5℃). We measured the body mass(M b)and body temperature(T b)of animals before and after each experiment. T b was measured by insertion of a digital thermometer into the rectum to a depth of 3 cm. Prior to each experiment, the animals fasted to four hours to minimize the specific dynamic action of food. Each test lasted for 1 h. All measurements were taken daily between 8:00-16:00. Metabolic rates were expressed as ml O 2/(g·h), corrected to STP condition. Thermal conductance(C, in ml O 2/ g·h·℃)was calculated at each temperature below the thermal neutral zone using the formula: C=MR/(T b-T a), where MR is metabolic rate (ml O 2/g·h), T b is body temperature(℃), T a is ambient temperature(℃). F value was calculated as F=[BMR(predicted BMR)/C(predicted C)], according to McNab(1970). The results showed that the mean basal metabolic rate(BMR)within thermal neutral zone was 3 49±0 36 ml O 2/(g·h). The thermal neutral zone(TNZ)was 25-32 5℃. Within the temperature range of 5-25℃, hamsters can keep their body temperature stable(36 33±0 23℃). Total thermal conductance(C)within the temperature range 5-25℃ was 0 28±0 01 ml O 2/(g·h·℃). Below the lower critical temperature, metabolic rate(MR)increased with the declining in ambient temperatures(T a), and the relationship between MR and T a can be described as: MR [ml O 2/(g·h)]= 9 60-0 22 T a(℃). Thus, the energetic characteristics of striped hamsters are: relative high level in BMR and C, wider TNZ, and relative lower body temperature. These properties might constrain the distribution and survival at extreme cold and areas for this species.更多还原