Bake Tina, Peris-Sampedro Fiona, Wáczek Zita, Ohlsson Claes, Pálsdóttir Vilborg, Jansson John-Olov, Dickson Suzanne L
Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
Centre of Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
J Neuroendocrinol. 2021 Aug;33(8):e12997. doi: 10.1111/jne.12997. Epub 2021 Jul 9.
The gravitostat is a novel homeostatic body weight-regulating mechanism, mostly studied in mice, and recently confirmed in obese humans. In the present study, we explored the effect of weight loading on metabolic outcomes, meal patterns and parameters linked to energy expenditure in both obese and lean rats. Diet-induced obese (DIO) and lean rats were implanted with capsules weighing either 15% of biological body weight (load) or empty capsules (1.3% of body weight; controls). Loading protected against fat accumulation more markedly in the DIO group. In line with this, the obesity-related impairment in insulin sensitivity was notably ameliorated in DIO rats upon loading, as revealed by the reduction in serum insulin levels and homeostatic model assessment for insulin resistance index scores. Although 24-hour caloric intake was reduced in both groups, this effect was greater in loaded DIO rats than in loaded lean peers. During days 10-16, after recovery from surgery, loading: (i) decreased meal size in both groups (only during the light phase in DIO rats) but this was compensated in lean rats by an increase in meal frequency; (ii) reduced dark phase locomotor activity only in lean rats; and (iii) reduced mean caloric efficiency in DIO rats. Muscle weight was unaffected by loading in either group. Dietary-obese rats are therefore more responsive than lean rats to loading.
重力调节器是一种新型的体内体重调节机制，主要在小鼠中进行研究，最近在肥胖人群中也得到了证实。在本研究中，我们探讨了体重负荷对肥胖和瘦大鼠的代谢结果、进食模式以及与能量消耗相关参数的影响。通过饮食诱导肥胖（DIO）的大鼠和瘦大鼠被植入重量为生物体重15%的胶囊（负荷）或空胶囊（体重的1.3%；对照组）。负荷对DIO组脂肪堆积的预防作用更为明显。与此一致的是，负荷后DIO大鼠胰岛素敏感性相关的肥胖损害明显改善，血清胰岛素水平降低以及胰岛素抵抗指数评分的稳态模型评估结果表明了这一点。虽然两组的24小时热量摄入均减少，但负荷后的DIO大鼠的这种效果比负荷后的瘦大鼠更为明显。在术后恢复的第10 - 16天，负荷：（i）两组的进食量均减少（仅在DIO大鼠的光照期），但瘦大鼠通过进食频率增加得到了补偿；（ii）仅在瘦大鼠中降低了暗期运动活动；（iii）降低了DIO大鼠的平均热量效率。两组中肌肉重量均不受负荷影响。因此，饮食诱导肥胖的大鼠比瘦大鼠对负荷更敏感。
