关键词: 能量收支, 被毛, 光周期, 黑线仓鼠, 温度, 热传导, 产热

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