半自然驯化条件下黑线姬鼠冬夏两季产热的比较

为探讨小型哺乳动物适应于季节性环境的产热机制,本文测定了户外半自然条件下驯化的黑线姬鼠(Apodemus agrarius)冬、夏两季的体重以及肝和褐色脂肪组织(Brown adipose tissue, BAT)的细胞色素c氧化酶及BATα-磷酸甘油氧化酶活力等指标.结果显示黑线姬鼠冬季体重显著降低,BAT绝对重量、BAT和肝的线粒体蛋白含量及BAT和肝酶的活力冬季均显著高于夏季.冬季BAT细胞色素c氧化酶活力是夏季的9.5倍,肝脏细胞色素c氧化酶活力是夏季的5倍;冬季BAT的α-磷酸甘油氧化酶活力高达夏季的19倍.以上结果表明,在寒冷的冬季为保证存活,黑线姬鼠降低体重以减少绝对能量需求,并极大地增加BAT重量及肝和BAT细胞水平上的产热能力.

Thermogenesis in Striped Field Nouse (Apodemus Agrarius) Under Summer and Winter Acclimation

In order to probe into the thermogenesis mechanism adapted to seasonal environment in small mammals,we measured body mass,activity of cytochrome c oxidase in liver and brown adipose tissue (BAT) and α-phosphoglycerate oxidase activity in BAT of striped field mouse (Apodemus agrarius) which was acclimated outdoor in winter and summer. Our results show that the animals' body mass decreased dramatically in winter. The absolute weight of BAT,the protein content of mitochondria in liver and BAT,the enzyme activity in BAT and liver were increased markedly in winter than in summer. Cytochrome c oxidase activity of BAT,cytochrome c oxidase activity of liver and α-phosphoglycerate oxidase activity of BAT were 9.5-fold higher,9-fold higher and 19-fold higher respectively in winter than those in summer. These results indicate that: in order to survival in the chilly winter, striped field mouse decrease the body mass to reduce the need of absolute energy. The animals also increase greatly the weight of BAT and enhance the thermogenesis capacity of liver and BAT in cellular level.