摘要
为研究能量代谢与消化道形态结构变化及其某些生活史特征之间的关系 ,采用食物平衡法、耗氧量测定、形态测量和组织学方法 ,分别测定了雄性、非繁殖雌性及哺乳雌性棕色田鼠 (Mirotusmandarinus)的摄食量、每日消化能、静止代谢率和胃肠器官长度、重量以及肠道各段管径和黏膜厚度。结果表明 :哺乳雌鼠摄食量、每日消化能、静止代谢率高于非繁殖雌鼠和雄鼠 ,且消化道各器官有最大的重量、管径和黏膜厚度。由此可见 ,哺乳雌鼠能量需求增加 ,促使消化道形态结构进行一些有益的调节。棕色田鼠在哺乳期代谢率增加时 ,仅有消化道器官重量、黏膜厚度及小肠管径的明显变化 ,这可能与其哺乳期较长 ,胎仔数较少 ,生后生长缓慢等生活史特征有关。同时也说明在未受到十分严峻的能量胁迫的情况下 ,动物并不需付出昂贵的代价去增加消化器官的长度 [动物学报 49(1) :32～ 39,2 0 0 3]。
Because the digestive tract morphology and energy demands of small mammals are correlated the former changes with ambient temperature, the seasons and reproductive state (lactation and pregnancy). However, these changes have different patterns in different mammals,i.e., the adaptive strategies of digestive tract morphology are different in different mammals. In this experiment, we chose the mandarin vole(Microtus mandarinus)as the animal model with which to investigate the relationship between energy demands,adaptive changes in digestive tract morphology and life-history traits.Specifically, we examined the energy metabolic rates of males,nonlactating females and lactating females and estimated the daily digestive energy(DDE)by means of feeding trials and the resting metabolic rate(RMR)by measuring oxygen consumption. In addition, we measured the length,mass and the perimeter and mocosal thickness of each digestive tract organ with normal morphological and histological methods. Differences in energy intake, digestive energy, digestibility, RMR, and perimeter and mocosal thickness of each digestive tract organ of the males, nonlactating females and lactating females were analyzed with one-way ANOVA. Differences in the mass and length of the digestive tract were analyzed with one-way ANCOVA. Results were as follows: in many cases, lactating females had the largest mass and perimeter and mocosal thickness of each digestive tract organ after controlling for body mass. The daily energy intake mandarin voles was 145.28±32.03 KJ for lactating females, 78.40±10.18 KJ for males and 71.37±16.42 KJ for nonlactating females. Daily digestive energy was 117.74±25.47 KJ(3.33±0.66 KJ/g) for lactating females, 59.87±9.02 KJ(1.96±0.32 KJ/g) for males and 57.08±12.70 KJ(1.93±0.44 KJ/g)for nonlactating females.RMR was 3.14±0.09 mlO 2/g.h for lactating females, and 2.14±0.09 mlO 2/g.h and 1.99±0.14 mlO 2/g.h for males and nonlactating females respectively. The energy intake, digestive energy and RMR of lactating females were higher than in males and nonlactating females. But, there were no significant changes in the length of each digestive tract organ of males, nonlactating females and lactating females. This suggests that adaptive changes in the morphology and structure of the digestive tract is related to the energy demands. Increased metabolic rate due to higher energy demands cause changes in some morphological and structural characteristics of the digestive tract; that is to say, an increase in energy demands cause the increase of metabolic rate. The morphology and structure of the digestive tract is changed in order to maintain the balance between the income and expenditure of energy. The digestive tract of mandarin voles has poor adaptive ability. Its metabolic rate changes less when the energy demands increase, which may be the cause of life-history traits such as longer lactation periods,smaller litter sizes and slower rates of postnatal growth. Besides, the results also indicate that the length of digestive tract doesn't change much in response to increased metabolic rate due to increased energy demands. Energy demands cause less expensive changes in digestive tract morphology and structure than increasing the length of digestive tract[Acta Zoologica Sinica 49(1):32-39,2003].
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2003年第1期32-39,共8页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金 (No .39870 119)资助项目 ~~
关键词
棕色田鼠
消化道
形态变化
能量需求
生活史特征
Mandarin vole(Microtus mandarinus), Digestive tract, Morphology variation, Energy metabolism, Life-history traits
