Dauncey M J, Brown D
AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge.
Q J Exp Physiol. 1987 Oct;72(4):549-59. doi: 10.1113/expphysiol.1987.sp003096.
The contribution made by spontaneous physical activity to 24 h energy expenditure has been assessed in lean and ob/ob mice living at 28 degrees C. Measurements were made in young animals when the ob/ob mice were the same body weight as their lean littermates, and again when they were adult and the ob/ob mice were twice as heavy as their littermates. In the young ob/ob mice, not only was 24 h heat production lower than in their lean littermates (P less than 0.005) but so also was motor activity (P less than 0.01). In adults, total 24 h heat production was similar in lean and obese animals, and thus on the basis of metabolic body size it was considerably lower in the obese adults (P less than 0.005). The obese adults were also significantly less active than their lean littermates (P less than 0.05). Differences between genotypes were particularly marked during the night. Partition of 24 h energy expenditure into the two components of rest and activity showed that in the young ob/ob mice the lower heat production occurred because they expended 31% less energy on rest and 47% less on activity than did their lean littermates. In the obese adults, the lower heat production per unit metabolic body size was accounted for by 16% less energy being expended on rest and 74% less on activity than in the lean mice. It is concluded that differences in motor activity between lean and ob/ob mice could account, at least in part, for the development and maintenance of obesity in these animals.
在28摄氏度环境下生活的瘦小鼠和ob/ob小鼠中，已对自发身体活动对24小时能量消耗的贡献进行了评估。在幼龄动物中进行了测量，此时ob/ob小鼠与它们的瘦同窝小鼠体重相同；在成年时再次进行测量，此时ob/ob小鼠的体重是其同窝小鼠的两倍。在幼龄ob/ob小鼠中，不仅24小时产热低于它们的瘦同窝小鼠（P<0.005），而且运动活动也较低（P<0.01）。在成年动物中，瘦小鼠和肥胖小鼠的24小时总产热相似，因此基于代谢体重，肥胖成年小鼠的产热显著更低（P<0.005）。肥胖成年小鼠的活动也明显少于它们的瘦同窝小鼠（P<0.05）。基因型之间的差异在夜间尤为明显。将24小时能量消耗分为休息和活动两个部分表明，在幼龄ob/ob小鼠中，产热较低是因为它们在休息时消耗的能量比瘦同窝小鼠少31%，在活动时少47%。在肥胖成年小鼠中，每单位代谢体重的较低产热是由于休息时消耗的能量比瘦小鼠少16%，活动时少74%。结论是，瘦小鼠和ob/ob小鼠之间的运动活动差异至少可以部分解释这些动物肥胖的发生和维持。
