Hammond K A, Kristan D M
Department of Biology, University of California, Riverside, CA 92521, USA.
Physiol Biochem Zool. 2000 Sep-Oct;73(5):547-56. doi: 10.1086/317757.
Recently, much interest has been expressed in understanding how animals use phenotypic plasticity of tissue size and function to meet increased metabolic demands. We set out to learn (i) whether female deer mice (Peromyscus maniculatus) given lactation (two to seven pups per litter), cold (5 degrees C), or cold plus lactation as energy demands display phenotypic plasticity in organ size and function; (ii) whether that plasticity is similar to laboratory mice given the same demands; and (iii) whether lactational performance in deer mice is derived from limits on central or peripheral organs. We found that deer mice responded to lactation by increasing digestible food intake and increasing the masses of the stomach, small intestine, cecum and liver, and the length of the small intestine. Heart mass was lower in lactating than in nonlactating mice. Cold exposure also caused increases in digestible food intake and increases in the masses of the small intestine, kidney, and heart. We conclude that deer mice display organ tissue plasticity in response to both lactation and cold exposure in a similar manner to laboratory mice. We also conclude that deer mice are not limited by central processing organs because they are able to increase digestive organ size continuously with increased energetic demands.
最近，人们对了解动物如何利用组织大小和功能的表型可塑性来满足增加的代谢需求表现出了浓厚兴趣。我们着手研究：（i）给予哺乳期（每窝产2至7只幼崽）、寒冷环境（5摄氏度）或寒冷加哺乳期的雌性鹿鼠（白足鼠），作为能量需求增加时，其器官大小和功能是否表现出表型可塑性；（ii）这种可塑性是否与给予相同需求的实验室小鼠相似；以及（iii）鹿鼠的泌乳性能是源于中枢器官还是外周器官的限制。我们发现，鹿鼠通过增加可消化食物摄入量以及增加胃、小肠、盲肠和肝脏的质量以及小肠长度来应对哺乳期。哺乳期小鼠的心脏质量低于非哺乳期小鼠。暴露于寒冷环境也会导致可消化食物摄入量增加以及小肠、肾脏和心脏质量增加。我们得出结论，鹿鼠对哺乳期和寒冷暴露的反应表现出器官组织可塑性，其方式与实验室小鼠相似。我们还得出结论，鹿鼠不受中枢处理器官的限制，因为它们能够随着能量需求的增加而持续增加消化器官的大小。
