Effects of overfeeding on energy balance and brown fat thermogenesis in obese (ob/ob) mice
Effects of overfeeding on energy balance and brown fat thermogenesis in obese (ob/ob) mice
复制标题
过度喂养对肥胖 (ob/ob) 小鼠能量平衡和棕色脂肪产热的影响
作者：
P. Trayhurn;P. M. Jones;M. McGuckin;A. Goodbody
遗传性肥胖（ob/ob）小鼠已被广泛用于肥胖的实验研究，并确定参与调节能量平衡的机制1。ob/ob小鼠从12天开始积累多余的能量2，但在哺乳期和4周龄内的食物摄入量并不高于瘦同胞3 -5。这表明ob/ob突变体中肥胖的最初发展完全是由于低能量消耗，并且这归因于体温调节非颤抖性产热的减少6 -8，特别是由棕色脂肪组织介导的减少9，10。然而，暴食症确实在ob/ob小鼠的肥胖症的后期发展中起重要作用。最近对Sprague-Dawley品系幼鼠进行的“自助餐饮食”研究表明，适应性饮食诱导的产热（也由棕色脂肪组织介导）在尽量减少自愿过度喂养期间的能量积累方面具有重要作用11 -13。我们现在报告的影响，过度喂养年轻的瘦和肥胖的小鼠与一个historeria型的饮食，并表明，虽然瘦动物保留很少的多余的能量摄入，大部分额外的摄入的肥胖小鼠的沉积。这表明，与瘦小鼠相比，肥胖小鼠的饮食诱导产热能力降低。我们还表明，两种基因型的能量平衡测量与棕色脂肪组织的不同适应性变化平行。
The genetically obese (ob/ob) mouse has been used extensively in experimental studies on obesity and to determine the mechanisms involved in regulating energy balance1. Excess energy begins to accumulate in the ob/ob mouse from ∼12 days of age2, but food intake during the suckling period and up to 4 weeks of age is no greater than in lean siblings3–5. This indicates that the initial development of obesity in the ob/ob mutant is entirely due to a low energy expenditure, and this has been attributed to a reduction in thermoregulatory non-shivering thermogenesis6–8, particularly that mediated by brown adipose tissue9,10. Hyperphagia does, however, play an important part in the later development of obesity in ob/ob mice. Recent studies with young rats of the Sprague–Dawley strain fed a ‘cafeteria diet’ have suggested that an adaptive diet-induced thermogenesis, also mediated by brown adipose tissue, has a major role in minimizing the accumulation of energy during voluntary overfeeding11–13. We now report the effects of overfeeding young lean and obese mice with a cafeteria-type diet, and show that while the lean animals retain little of their excess energy intake, most of the extra intake of the obese mice is deposited. This suggests that the capacity for diet-induced thermogenesis is reduced in the obese compared with the lean mice. We also show that the energy balance measurements are paralleled by different adaptive changes in brown adipose tissue in the two genotypes.