Nadreau E, Baraboi E-D, Samson P, Blouin A, Hould F-S, Marceau P, Biron S, Richard D
Laval Hospital Research Center, 2725, chemin Sainte-Foy, Québec, Canada.
Int J Obes (Lond). 2006 Mar;30(3):419-29. doi: 10.1038/sj.ijo.0803166.
This study was carried out to determine the effects of the biliopancreatic diversion (BPD), a bariatric surgery applied to the treatment of morbidly obese humans, on energy balance in rats.
BPD was performed on a group of male Wistar rats. Body weight and food intake were measured daily throughout the study. Feces were also collected to assess energy losses and the determination of digestible energy. Energy expenditure and body composition were also determined for the 50-day length of the protocol. On the day of killing, the brain, the entire intestinal tract and white and brown adipose tissues were collected and weighed. Expression of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the ARC nucleus were assessed by in situ hybridization.
Marked changes in the regulation of energy balance were observed in the BPD-operated rats. A decrease in digestible energy and food intake coupled with an increase in the fecal energy density and protein fecal energy led to an important weight loss in the BPD-operated rats. This weight loss was observed in the loss of fat mass (specifically the white epididymal, inguinal, retroperitoneal and brown adipose tissues). The rats modified their food intake pattern to be able to potentially eat more during the entire day. An increase in the surfaces of all intestinal structures (muscular and mucosal layers) was observed in the BPD-operated rats. The NPY and AgRP expression in the brain were both shown to be greater in the BPD-operated rats than in the control animals. At the beginning of the study, the surgery led to an energy expenditure decrease, which, however, did not persist throughout the study despite the fact that BPD-operated rats exhibited persistent lower fat free masses.
BPD led to a noticeable reduction in weight and fat gains in rats, which was in large part owing to a decrease in digestible energy intake led to by the gastrectomy, the intestinal malabsorption inherent to the surgery and to potentially a thermogenesis stimulation that occurred in the second end of the study. The reduction in energy gain occurs despite adaptations to thwart the intestinal malabsorption and the hunger signals from the central nervous system.
本研究旨在确定用于治疗病态肥胖人类的减肥手术——胆胰分流术（BPD）对大鼠能量平衡的影响。
对一组雄性Wistar大鼠实施BPD手术。在整个研究过程中每天测量体重和食物摄入量。还收集粪便以评估能量损失并测定可消化能量。在为期50天的实验方案中还测定了能量消耗和身体组成。在处死当天，收集并称重大脑、整个肠道以及白色和棕色脂肪组织。通过原位杂交评估弓状核中神经肽Y（NPY）和刺鼠相关蛋白（AgRP）的表达。
在接受BPD手术的大鼠中观察到能量平衡调节发生了显著变化。可消化能量和食物摄入量减少，同时粪便能量密度和粪便蛋白质能量增加，导致接受BPD手术的大鼠体重显著减轻。这种体重减轻表现为脂肪量减少（特别是附睾白色、腹股沟、腹膜后和棕色脂肪组织）。大鼠改变了它们的食物摄入模式，以便能够在一整天内潜在地摄入更多食物。在接受BPD手术的大鼠中观察到所有肠道结构（肌肉层和黏膜层）的表面积增加。与对照动物相比，接受BPD手术的大鼠大脑中的NPY和AgRP表达均更高。在研究开始时，手术导致能量消耗减少，然而，尽管接受BPD手术的大鼠表现出持续较低的去脂体重，但这种情况在整个研究过程中并未持续。
BPD导致大鼠体重和脂肪增加显著减少，这在很大程度上归因于胃切除术导致的可消化能量摄入减少、手术固有的肠道吸收不良以及可能在研究后期发生的产热刺激。尽管机体进行了适应性调节以克服肠道吸收不良和中枢神经系统发出的饥饿信号，但能量增加仍有所减少。
