达乌尔黄鼠产热的季节性变化

达乌尔黄鼠（Ｃｉｔｅｌｌｕｓｄａｕｒｉｃｕｓ）的产热表现出明显的季节性变化。在非冬眠期，静止代谢率（ＲＭＲ）和非颤抖性产热（ＮＳＴ）于春季最高，秋季次之，夏季最低。冬眠期，ＲＭＲ降到极低水平，只为春季的３．０％。肝脏的线粒体蛋白含量、线粒体呼吸和细胞色素Ｃ氧化酶活力在秋季显著高于其它各季。褐色脂肪组织（ＢＡＴ）的重量、线粒体蛋白含量、细胞色素Ｃ氧化酶活力和α－磷酸甘油氧化酶活力，在夏季处于一年中的最低水平，到了冬季这些指标达到一年中的最高水平。在非冬眠季节ＢＡＴ产热能力升高时，ＮＳＴ能力也相应升高，这表明ＢＡＴ产热能力的增强是ＮＳＴ能力提高的部分机制。达乌尔黄鼠血清Ｔ＿４含量在年周期中没有明显改变，冬眠时血清Ｔ＿３含量显著高于其它各季。

SEASONAL VARIATIONS OF THERMOGENESIS IN DAURIAN GROUND SQUIRREL (CITELLUS DAURICUS)

The thermogenesis of Daurian ground squirrel (Citellus dauricus) showed apparent seasonal variation. Resting metabolic rate (RMR) and non-shivering thermogenesis (NST) in non-hibernating seasons were the highest in spring and the lowest in summer.RMR keeped extremly low during hibernation. The protein content, respiration and activity of cytochrome C oxidase of liver mitochondria were much higher in autumn than in other seasons. The wet weight, mitochondrial protein content, activities of cytochrome C oxidase and a-phosphoglycerol oxidase of brown adipose tissue (BAT) were the lowest in summer and the highest during hibernation. The increase of thermogenic capacity of BAT corresponded to the increase of NST, suggesting that BAT thermogenesis was reponsible for NST. Serum T 4 concentration in Daurian ground squirrel did not change significantly in annual cycle, but serum T3 concentration was obviously higher during hibernation than in non-hibernating seasons.