Laboratory of Metabolism, Department of Internal Medicine, University of Geneva, Geneva, Switzerland.
Am J Physiol Endocrinol Metab. 2011 Jun;300(6):E1146-57. doi: 10.1152/ajpendo.00575.2010. Epub 2011 Mar 15.
Recent studies describe the Lou/C rat as a model of resistance to age- and diet-induced obesity and suggest a preferential channeling of nutrients toward utilization rather than storage under standard feeding conditions. The purpose of the present study was to evaluate lipid metabolism of Lou/C and Wistar rats under a high-fat (HF) diet. Four-month-old male Lou/C and Wistar animals were submitted to a 40% HF diet for 5-9 wk. Evolution of food intake, body weight, and body composition, hormonal parameters, and expression of key transcription factors and enzymes involved in lipid metabolism were determined. Wistar rats developed obesity after 5 wk of HF diet, as previously described. Among the various parameters measured, accumulation of intraperitoneal fat was particularly evident in HF-fed Wistar rats. In these animals, thermogenesis was, however, stimulated as a likely compensatory mechanism against the development of obesity. On the contrary, Lou/C animals failed to develop obesity under such a diet, and intraperitoneal fat, not including epididymal and retroperitoneal fat depots, was virtually absent. Enzyme measurements confirmed lipid utilization rather than storage, which was accompanied by the striking emergence of uncoupling protein-1, characteristic of brown adipocytes, in white adipose tissue, particularly in the subcutaneous depot.
最近的研究描述了 Lou/C 大鼠作为抵抗年龄和饮食引起的肥胖的模型，并表明在标准喂养条件下，营养物质更倾向于被利用而不是储存。本研究的目的是评估高脂肪（HF）饮食下 Lou/C 和 Wistar 大鼠的脂质代谢。4 月龄雄性 Lou/C 和 Wistar 动物接受 40%HF 饮食 5-9 周。测定了食物摄入、体重和体成分、激素参数以及参与脂质代谢的关键转录因子和酶的表达。正如先前所述，Wistar 大鼠在接受 HF 饮食 5 周后会发生肥胖。在测量的各种参数中，HF 喂养的 Wistar 大鼠腹腔内脂肪的积累尤为明显。然而，在这些动物中，产热被作为一种可能的补偿机制来刺激，以对抗肥胖的发展。相反，Lou/C 大鼠在这种饮食下不会发生肥胖，而且几乎不存在腹腔内脂肪，包括附睾和腹膜后脂肪储存。酶测量证实了脂质的利用而不是储存，这伴随着解偶联蛋白-1的显著出现，这是棕色脂肪细胞的特征，特别是在皮下脂肪储存中。
