Zhao Zhi-Jun, Wang De-Hua
State Key Laboratory of Integrated Management for Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Physiol Biochem Zool. 2009 Sep-Oct;82(5):504-15. doi: 10.1086/603630.
Small mammals usually show physiological and behavioral adaptations to cope with seasonal changes in food quality and availability. To examine the adaptive strategy of small rodents responding to varying dietary quality, we acclimated Mongolian gerbils (Meriones unguiculatus) to a high-fiber diet (HF: 35.5% neutral detergent fiber [NDF] and 21.4% acid detergent fiber [ADF]) for 4 wk and then a relatively low-fiber diet (LF: standard rat chow, 12.8% NDF and 4.8% ADF) for another 4 wk. Body mass was stable over the course of acclimation, but food intake and the size and mass of the digestive tract increased significantly in HF gerbils. The HF diet induced a decrease in basal metabolic rate and nonshivering thermogenesis associated with a reduction in the uncoupling protein 1 content of brown adipose tissue. After 4 wk of subsequent feeding on the LF diet, body mass, energy intake, digestive tract morphology, and thermogenic capacity recovered to the baseline. Serum leptin level decreased in HF gerbils and increased in the gerbils then fed with the LF diet. Further, the change in serum leptin level was positively related to body fat mass and negatively related to food intake, suggesting that the decreased leptin level associated with lower body fat content might be a signal that an animal was in negative energy balance. Finally, our data indicated that energy intake, body composition, and organ morphological plasticity are the main strategies by which gerbils cope with variations in food quality. Change in serum leptin level is related to change in food intake in Mongolian gerbils.
小型哺乳动物通常会表现出生理和行为上的适应性变化，以应对食物质量和可获得性的季节性变化。为了研究小型啮齿动物对不同饮食质量的适应性策略，我们将蒙古沙鼠（Meriones unguiculatus）先适应高纤维饮食（HF：35.5%中性洗涤纤维[NDF]和21.4%酸性洗涤纤维[ADF]）4周，然后再适应相对低纤维饮食（LF：标准大鼠饲料，12.8% NDF和4.8% ADF）4周。在适应过程中，体重保持稳定，但HF组沙鼠的食物摄入量以及消化道的大小和重量显著增加。HF饮食导致基础代谢率和非颤抖性产热降低，这与棕色脂肪组织中解偶联蛋白1含量的减少有关。在随后4周的LF饮食喂养后，体重、能量摄入、消化道形态和产热能力恢复到基线水平。HF组沙鼠的血清瘦素水平下降，而在随后喂食LF饮食的沙鼠中血清瘦素水平升高。此外，血清瘦素水平的变化与体脂量呈正相关，与食物摄入量呈负相关，这表明与较低体脂含量相关的瘦素水平降低可能是动物处于负能量平衡的一个信号。最后，我们的数据表明，能量摄入、身体组成和器官形态可塑性是沙鼠应对食物质量变化的主要策略。蒙古沙鼠血清瘦素水平的变化与食物摄入量的变化有关。
