根田鼠冷驯化过程中的适应性产热特征

ADAPTIVE THERMOGENIC PROPERTYS DURING COLD EXPOSURE IN ROOT VOLES (MICROTUS OECONOMUS)

对栖居于青海高原的根田鼠（Ｍｉｃｒｏｔｕｓ ｏｅｃｏｎｏｍｕｓ）于冷驯化（５℃） １、 ７和 ２１天的非颤抖性产热（ＮＳＴ）、褐色脂肪组织（ＢＡＴ）和肝脏的组织蛋白和线粒体蛋白含量、心脏和肌肉的线粒体蛋 白含量、四种组织线粒体的细胞色素氧化酶活力及肝脏线粒体的状态Ⅵ呼吸能力等指标进行了测 定。结果表明：冷驯化过程中ＮＳＴ趋于增加，有一个逐渐发展的过程；ＢＡＴ线粒体蛋白含量对低温的反应比组织蛋白的反应剧烈，肝脏、心脏和肌肉组织的线粒体蛋白含量变化较温和，但各种组 织的细胞色素氧化酶活力随冷驯化而急剧增加，肝脏线粒体的状态Ⅵ呼吸能力加强。结果说明 ＮＳＴ在低温下的热能调节过程中占十分重要的地位，肌肉、心脏、肝脏等组织也参与了体温调节过程。在自然生境中，低温是一重要的刺激调节因子。

The nonshivering thermogenesis (NST), tissue and mitochondrial protein contents of brown adipose tissue (BAT) and liver, mitochondrial protein contents of heart and limb- muscle, cytochrome oxidase activities of the above four tissues, and the state tV respiratory ability of liver mitochondria in root vole (Microtus oeconomus), which live in the clod alpine meadow of Qinghai-Tibetan Plateau, during cold exposure for 1 day,7 days and 21 days, were determined. The results showed that NST tend to increase with a gradual developing process, and the content of BAT mitochondrial protein showed a stronger response to clod than that of tissue protein. The variation of mitochondrial protein contents of liver, heart and limb-muscle showed moderate responses, while the cytochrome oxidase activities of all the tissues increased markedly with cold exposure. The state Ⅳrespiratory ability of liver mitochondria enhanced during cold exposure. These results suggest that NST play an im- portant role in the process of thermoregulation, and muscle, heart and liver are also involved in the thermoregulation under cold exposure for the voles. Thus, under natural environment, low temperature is an important stimulatory and adjustmental factor for thermogenesis.