Adaptive thermogenesis is intact in B6 and A/J mice studied at thermoneutrality
Adaptive thermogenesis is intact in B6 and A/J mice studied at thermoneutrality
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DOI：
10.1016/j.metabol.2004.06.007
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发表时间：
2004-11-01
影响因子：
9.8
通讯作者：
Overton, JM
中科院分区：
文献类型：
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作者：
DeRuisseau, LR;Parsons, AD;Overton, JM
为探讨抗肥胖的机制，在室温（T-a）= 23 ℃和热中性（T-a = 30 ℃）条件下，研究了肥胖易感小鼠（B6）和肥胖抵抗小鼠（A/J）对短期适度脂肪喂养的生理反应。我们假设，A/J小鼠将表现出更大的适应性产热反应消耗中等脂肪的饮食，这种反应将减弱在热中性条件下，由于棕色脂肪组织（BAT）的活动减少。将B6和A/J小鼠适应于T-a = 23 ℃或T-a = 30 ℃，植入遥测装置，置于代谢室中以测量食物摄入量、耗氧量（VO 2）和心率（HR），并在食用含有32%来自脂肪的卡路里的饮食之前和期间进行研究。获得32%的脂肪饮食导致两种品系的热量摄入增加，但A/J小鼠的热量摄入在72小时内恢复到基线水平，而B6小鼠保持高摄食。两种菌株都表现出增加的光相VO 2适应性产热的指示，但是，有没有在1周的喂养试验中的光相VO 2的菌株差异。令人惊讶的是，T。在任一小鼠品系中对饮食诱导的产热没有影响。中度高脂喂养产生轻度心动过速，这在B6和A/J小鼠中相似，在热中性时更明显。我们的结论是，适应性产热反应是完整的，在两个小鼠品系研究在热中性，这表明BAT在最初的代谢反应，以摄食过多的最小作用。此外，研究结果表明，在控制热量摄入的差异，而不是适应性产热的能力，可能有助于在A/J和B6小鼠肥胖的相对易感性。(C)2004爱思唯尔公司All rights reserved.
To investigate mechanisms of resistance to obesity, the physiologic responses to short-term moderate fat feeding were studied at ambient temperature (T-a) = 23degreesC and thermonuetrality (T-a = 30degreesC) in mice susceptible (B6) or resistant (A/J) to obesity. We hypothesized that A/J mice would exhibit greater adaptive thermogenic responses to consumption of moderate-fat diets, and that this response would be attenuated in thermoneutral conditions due to reduced activity of brown adipose tissue (BAT). B6 and A/J mice were adapted to either T-a = 23degreesC or T-a = 30degreesC, implanted with telemetry devices, housed in metabolic chambers for measurement of food intake, oxygen consumption (VO2), and heart rate (HR), and studied before and during 1 week of consuming a diet containing 32% of calories from fat. Access to 32% fat diet resulted in increased caloric intake in both strains, but caloric intake for A/J mice returned to baseline levels within 72 hours, while B6 mice remained hyperphagic. Both strains exhibited increased light-phase VO2 indicative of adaptive thermogenesis; however, there was no strain difference in light-phase VO2 during the 1-week feeding trial. Surprisingly, T. had no effect on diet-induced thermogenesis in either mouse strain. Moderate high-fat feeding produced mild tachycardia that was similar in B6 and A/J mice and more clearly evident at thermonuetrality. We conclude that adaptive thermogenic responses are intact in both mouse strains studied at thermoneutrality, suggesting a minimal role for BAT in the initial metabolic response to hyperphagia. Furthermore, the results suggest that differences in control of caloric intake, rather than capacity for adaptive thermogenesis, may contribute to the relative susceptibility to obesity in A/J and B6 mice. (C) 2004 Elsevier Inc. All rights reserved.