非冬眠期达乌尔黄鼠对低温的适应性产热

ADAPTIVE THERMOGENESIS OF DAURIAN GROUND SQUIRREL (CITELLUS DAURICUS) DURING COLD ACCLIMATION IN SUMMER

达乌尔黄鼠在夏季冷驯化低温环境下（５±１℃）暴露４周后，导致脂肪积累的抑制；其静止代谢率（ＲＭＲ）和非颤抖性产热（ＮＳＴ）分别提高了１２％和８５％；肝脏线粒体的蛋白含量、状态３呼吸和细胞色素Ｃ氧化酶活力分别提高了２２％、４２％和４８％，表明在低温环境下肝脏线粒体产热能力的增强是ＲＭＲ提高的细胞学机制之一；褐色脂肪组织（ＢＡＴ）的重量、蛋白含量、细胞色素Ｃ氧化酶活力和α－磷酸甘油氧化酶活力极显著提高，表明在低温环境下ＢＡＴ是达乌尔黄鼠的主要产热器官，ＢＡＴ产热能力的增强是ＮＳＴ提高的重要细胞学机制之一。冷驯化没有引起达乌尔黄鼠血清Ｔ３。

After four weeks of cold acclimation(5±1℃) in summer fat accumulation was inhibited in Daurian ground squirrel (Citellus dauricus) .Resting metabolic rate(RMR) and non shivering thermogenesis(NST)showed an increase of 12% and 85% respectively.The protein content,state 3 respiration and cytochrome C oxidase activity of liver mitochondria showed an increase of 22%,42%and 48% respectively, suggesting the enhancement of thermogenic capacity of liver was one of the celluar mechanisms of the rise of RMR.The weight,protein content,activity of cytochrome C oxidase and α phosphoglycerol oxidase of brown adipose tissue(BAT) were markedly improved,suggesting that BAT is the main thermogenenic organ and the enhancement of capacity of BAT thermogenesis is one of the celluar mechanisms of the increase of NST during cold acclimation. Serum T 3 and T 4 concentration did not change obviously during cold acclimation in Daurian ground squirrel.