禁食和重喂食对大绒鼠体重、产热和血清瘦素的影响

Effects of fasting and refeeding on body mass, thermogenesis and serum leptin in Eothenomys miletus

动物行为和生理活动的适应性调节是应对食物资源变化的主要策略。为探讨禁食和重喂食对大绒鼠体重、产热和血清瘦素的影响,测定了禁食和重喂食条件下大绒鼠的体重、体脂重量、静止代谢率、身体组成、血清瘦素含量以及禁食后重喂食期间的摄食量。结果显示:禁食导致大绒鼠体重、体脂重量和静止代谢率显著下降,重喂食后体重和静止代谢率能够恢复到对照组水平,而体脂重量却不能恢复。禁食12h后血清瘦素含量快速下降,重喂食后未能恢复到对照水平。此外,大绒鼠在禁食后重喂食期间摄食量没有补偿性增加,血清瘦素含量与体脂重量呈正相关关系。这些结果很可能反映出大绒鼠能调节自身生理状况以适应短期的能量缺乏,主要通过降低体重、血清瘦素含量和代谢活性器官重量以减少能量消耗。禁食后重喂食时大绒鼠没有摄食过量。血清瘦素的下降早于体重和体脂的下降。

The adaptive control of animal behavior and physiological activities is the main strategy in response to the change of food resources. To investigate the effect of fasting and refeeding on the body mass, thermogenesis and serum leptin in Eo- thenomys miletus, changes in body and body fat mass, resting metabolic rate （RMR） , body composition, serum leptin level and post-fasting food intake were monitored and measured. The data showed significant fasting-induced reductions in body mass and body fat mass. Body mass, but not body fat, can be restored to the control level in refeeding voles. RMR de- creased significantly in response to fasting, and can return to the control level after refeeding. Fasting for 12 hours induced a rapid reduction in serum leptin content, it can not recover the control level after refeeding. Interestingly, there were no post- fasting compensatory increases in food intake. There was a positive relation between serum leptin level and body fat mass. Our data indicate that E. miletus can adjust their physiological functions integratively to cope with starvation by decreasing body mass, adaptive thermogenesis and serum leptin level. There is no post-fasting hyperphagia in E. miletus. The reduction of serum leptin was somewhat earlier than the decline in body fat and body mass.