随机限食和重喂食小鼠能量收支和生长发育的可塑性

Effect of Random Food Deprivation and Refeeding on Energy Budget and Development in Mice

为阐明能量收支和生长发育的可塑性对动物适应食物资源变化的作用和意义,将断乳后的雄性KM小鼠40只随机限食4周,再重喂食4周。采用封闭式流体压力呼吸计测定基础代谢率(BMR)。限食使摄食量显著增加,BMR和活动行为降低,胴体和生殖腺重量显著降低。重喂食后上述指标均恢复到对照组水平,表现出显著的可塑性变化。结果表明,KM小鼠能通过摄食量、BMR、活动行为和身体组成的可塑性调节以适应难以预测的食物资源变化。

Significance of plasticity in energy budget and development of animals in response to variations of food availability was examined in weaned male KM mice that were acclimated to random food deprivation （FD） for 4 weeks, followed by feeding ad libtum for a following 4 weeks. Food intake was determined using a food balance method. Basal metabolic rate （BMR） was measured using a closed-circuit respirometer. Food intake increased significantly on ad libitum day in FD mice, but BMR and activity decreased. FD mice also had a significantly lower weight in carcass and gonadal gland than controls after 4 weeks of FD. All the above parameters recovered to the levels of controls after 4 weeks of ad libitum refeeding, indicating a significant plasticity. In addition, the group difference in fat content was not significant. These results suggest that animals can compensate for unpredictable lower food availability by an energetic strategy, including an increase in food intake and a decrease in energy expenditure associated with BMR and activity, and decrease in carcass mass thus reduced energy spent on maintenance, but not including the changes in body fat. Development is affected significantly by lower food availability but recovers to the normal level when food is plentiful. Finally, plasticity in the energetic budget and development play important roles in animals under unpredictable variations of foodavailability.