Abstract: To examine the relationship between the energy strategy in response to food restriction and the levels of metabolism in small mammals,body mass,basal metabolic rate (BMR)and nonshivering thermogenesis (NST)were measured in striped hamsters (Cricetulus barabensis)that were subjected to different levels of food restriction (FR). The data showed
that BMR,NST and cytochrome c oxidase activity of brown adipose tissue all were significantly decreased in FR hamsters. Eighty percent of hamsters survived for 4 weeks after being restricted to 90% of ad libitum food intake,but survival rate was 30% in hamsters restricted to 60% of ad libitum food intake. Cold-exposed hamsters had significantly increased BMR and NST,but had decreased body mass and survival rate after being restricted to 80% of ad libitum food intake compared with their counterparts maintained at room temperature. Hamsters with higher BMR consumed 23.8% higher food than individuals with lower BMR,whereas no differences were observed in body mass and survival rate between the two groups after being restricted to 80% of ad libitum food intake. This suggests that striped hamsters characterized by higher levels of metabolism are sensitive to periods of FR,providing a support for the ‘metabolism switch hypothesis’. Finally,the present study is consistent with the prediction that small mammals showing food shortage behavior may have less ability to cope with decreases in food availability.

Key words: Basal metabolic rate (BMR), Body mass, Food restriction, Striped hamster, Thermogenesis

摘要： 为阐明动物应对食物短缺的能量学对策与其自身的代谢水平的关系,测定了不同限食程度下黑线仓鼠的体重、基础代谢率和非颤抖性产热。结果发现,限食使基础代谢率、非颤抖性产热、褐色脂肪组织细胞色素c氧化酶活性降低。90% 限食驯化4 周后,存活率为80% ,60% 限食驯化4 周后,存活率为30% 。低温驯化使黑线仓鼠基础代谢率和非颤抖性产热显著增加,使80% 限食动物的体重和存活率显著降低。高基础代谢率组的摄食量比低基础代谢率组多23.8% ,80% 限食后两组体重降低的幅度和存活率差异不显著。结果表明:高水平的代谢率使黑线仓鼠对食物资源短缺的敏感性增加;支持“代谢率转换假说”,符合“具有储食习性的动物对食物短缺的生理耐受性较低” 的预测。

关键词: 基础代谢率, 体重, 食物限制, 黑线仓鼠, 产热