Levin I, Trayhurn P
Am J Physiol. 1987 May;252(5 Pt 2):R987-93. doi: 10.1152/ajpregu.1987.252.5.R987.
The effects of different food deprivation regimens on the thermogenic activity and capacity of brown adipose tissue in the golden hamster have been investigated. Thermogenesis in the tissue was assessed by measurements of tissue cytochrome-c oxidase activity, mitochondrial GDP binding, and the specific mitochondrial concentration of uncoupling protein. The thermogenic activity and capacity of brown adipose tissue were found to be markedly reduced in fasted or underweight hamsters. Measurements of cytochrome-c oxidase activity indicate that the reductions were caused exclusively by a loss in mitochondrial mass, uncoupling protein concentration and GDP binding to mitochondria remaining unchanged. The decrease in brown adipose tissue thermogenesis was associated with a reduction in the capacity for nonshivering thermogenesis in the whole animal. Hamsters recovered from weight losses without increasing their food intake, and the recovery was accompanied by a normalization in mitochondrial mass in brown adipose tissue. Mitochondrial mass was, however, restored only after 10 days of ad libitum refeeding. These results suggest that the reduction in energy expenditure in the fasted hamster could relate to a decrease in brown adipose tissue thermogenesis, in addition to the previously reported decreases in resting metabolic rate and locomotor activity. Reductions in thermogenesis may also represent a further mechanism by which energy stores recover in the golden hamster without postfast hyperphagia.
研究了不同食物剥夺方案对金黄仓鼠棕色脂肪组织产热活性和能力的影响。通过测量组织细胞色素c氧化酶活性、线粒体GDP结合以及解偶联蛋白的特定线粒体浓度来评估组织中的产热情况。发现在禁食或体重过轻的仓鼠中，棕色脂肪组织的产热活性和能力显著降低。细胞色素c氧化酶活性的测量表明，这种降低完全是由线粒体质量的损失引起的，解偶联蛋白浓度和GDP与线粒体的结合保持不变。棕色脂肪组织产热的降低与整个动物非寒战产热能力的降低有关。仓鼠在不增加食物摄入量的情况下从体重减轻中恢复，恢复过程伴随着棕色脂肪组织线粒体质量的正常化。然而，线粒体质量仅在自由采食10天后才恢复。这些结果表明，禁食仓鼠能量消耗的降低可能与棕色脂肪组织产热的减少有关，此外还有先前报道的静息代谢率和运动活动的降低。产热的降低也可能代表了金黄仓鼠在不出现禁食后贪食的情况下能量储备恢复的另一种机制。
