为阐明动物应对食物短缺的能量学对策,将成年大绒鼠按自由取食量的90%、80%和70%限食4周。测定了不同限食程度下大绒鼠的存活率、体重、体脂含量、血清瘦素浓度、基础代谢率和非颤抖性产热。结果发现,90%限食驯化4周后,动物没有死亡,80%限食驯化4周后,存活率为90%,而70%限食驯化4周后,存活率仅为60%。限食使大绒鼠体重、体脂含量、血清瘦素浓度、基础代谢率和非颤抖性产热降低。血清瘦素浓度与体重、基础代谢率和非颤抖性产热呈显著正相关。结果表明,在限食条件下,大绒鼠主要通过降低体重、基础代谢率和产热的能量支出以及动用体内脂肪以应对食物资源短缺的环境条件,符合“代谢率转换”假说。瘦素作为饥饿信号可能参与了限食条件下大绒鼠能量代谢和体重的适应性调节。
To investigate the energy strategy in response to food restriction, adult Eothenomys miletus were stochastically restricted to 90% , 80% and 70% of ad libitum food intake for four weeks. Survival rate, body mass, body fat content, ser- um leptin levels, basal metabolic rate (BMR) and nonshivering thermogenesis (NST) in E. miletus were measured. The results showed that there were no deaths when E. miletus were restricted to 90% of ad libitum food intake. However, the lowest survival rate (60%) of E. miletus was observed after 70% of ad libitum food intake for four weeks, and the body mass, body fat content, serum leptin levels, BMR and NST were lower than those in control group. In addition, serum lep- tin levels were positively correlated with body mass, BMR and NST. These results suggested that E. miletus applied physio- logical adjustments to adapt the period of food shortage by reducing body mass, body fat content and energy metabolism, providing a support for the "metabolism switch hypothesis". Serum leptin may acts as a hunger signals, and may be in- volved in the regulation of energy balance and body mass in E. miletus during the food restriction.