Abstract: The role of seasonal change of hair in the regulation of energy budget and thermoregulation were examined in small mammals in the present study. Weight of hair,body temperature and energy budget were determined in striped hamsters (Cricetulus barabensis)that were wild-captured over four seasons,and also in hamsters acclimated to short photoperiod and cold conditions. The results showed that (1)Winter hamsters had significantly higher thermogenesis and heavier hair than summer hamsters;(2)Regrowth of the hair was not affected by short photoperiod (8L∶16D)and cold temperature (5℃ ); (3)Energy intake,basal metabolic rate (BMR),nonshivering thermogenesis (NST),activity of cytochrome c oxydase of brown adipose tissue and thermal conductance significantly increased in the hamsters exposed to 5℃ ,while they decreased in the hamsters acclimated to 30℃ in comparison with subjects maintained at 21℃ ;(4)Hair removal induced significant increases in energy intake,BMR,NST and the rate of thermal conductance at 21℃ and 5℃ ,respectively. These findings suggest that the role of hair in the regulation of energy budget and thermoregulation are likely associated with ambient temperature, by which the insulation provided by the hair decreases energy demands and consequently enhances the capacity to cope with the cold temperatures. Seasonal changes in the hair are employed by the individual wild small mammals in response to seasonal environment fluctuations,and thus play important roles in the regulations of energy metabolism and thermoregulation.

Key words: Energy budget, Hair, Photoperiod, Striped hamster (Cricetulus barabensis), Temperature, Thermal conductance, Thermogenesis

摘要： 为阐明小型哺乳动物被毛的季节性变化及其在能量代谢和体温调节中的作用,测定了季节性驯化,以及不同光周期和温度驯化的黑线仓鼠的被毛重量、体温和能量收支。结果显示: (1)冬季黑线仓鼠的被毛重量和产热显著高于夏季;(2)短光照(8L∶16D)和低温(5℃ ) 对被毛生长的影响不显著; (3)与室温组(21℃ )相比,低温组(5℃ )摄入能、基础代谢率(BMR)、非颤抖性产热(NST) 、褐色脂肪组织细胞色素c 氧化酶活性和热传导率显著增加,而暖温组(30℃ )显著降低; (4)室温和低温下,剃毛导致摄入能、BMR、NST 和热传导率显著增加;结果表明:被毛的作用与环境温度有关,低温下被毛降低了能量需求,增强了动物应对低温环境的适应能力;被毛的适应性变化是独居的野生小型哺乳动物应对环境温度季节性波动的主要适应策略之一,在其能量代谢和体温调节中具有重要作用和意义。

关键词: 能量收支, 被毛, 光周期, 黑线仓鼠, 温度, 热传导, 产热