禁食和重喂食对大绒鼠消化道长度与重量的影响

Effects of Fasting and Refeeding on Mass and Length of Digestive Tract in Eothenomys miletus

为探讨禁食和重喂食对栖息于横断山地区大绒鼠(Eothenomys miletus)消化道形态的影响,对禁食和重喂食条件下大绒鼠消化道各项指标进行了测定。实验分别测定了大绒鼠禁食12 h、24 h、36 h和重喂食12 h、48 h、7 d后的总消化道、胃、小肠、大肠、盲肠的长度及其含内容物重、去内容物重、干重。结果表明:禁食后,总消化道含内容物重、胃含内容物重和胃去内容物重增加,重喂食7 d后均恢复到对照组水平。小肠含内容物重在禁食12 h时最大,在重喂食12 h时最小,重喂食48 h后恢复到对照组水平。禁食和重喂食条件下,大绒鼠的大肠和盲肠各指标均没有显著变化。以上结果表明,大绒鼠在食物受到限制、饥饿等胁迫因子作用下,可能通过调节消化道形态来满足部分能量需求,维持正常的生理机能。大绒鼠的消化道在禁食和重喂食中表现出的变化模式,可能与其食物资源时常波动的野外生存环境有关,从一方面反映了该物种在食物胁迫下的生存机制和适应对策。

In order to investigate the effects of fasting and refeeding on digestive tract morphology in Eothenomys miletus from Hengduan Mountain region, weights and lengths of total digestive tract morphology including stomach, small intestine, large intestine and caecum, were measured from individuals fasting （12 h, 24 h, 36 h） and refeeding （12 h, 48 h, 7 d）. The results shown that weight with contents of total digestive tract, weight with contents and weight without contents of stomach increased significantly under fasting acclimation, and all these values returned to the levels of control group after refeeding. Maximum weight of small intestine appeared in group fasting for 12 h, and minimal value shown in the refeeding 12 h group. The small intestine weight was back to the level of control group after refeeding 48 h. Any index of large intestine and caecum has no significant change in fasting and refeeding conditions. These results indicated that E. miletus might adjust the weight of digestive tract to maintain the normal physiological function in stressed condition, such as lack of food and starvation. The change pattern of digestive tract in E.miletus in fasting and refeeding condition was related to its survive in their environment, which food resource is varied. Our results suggest that the adjustments in capacity and size of the gastrointestinal tract play an important role in their digestive strategies in natural environment.