Université de Strasbourg, IPHC-DEPE, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR 7178, 23 rue Becquerel, 67087 Strasbourg, France.
Horm Behav. 2013 Sep;64(4):611-7. doi: 10.1016/j.yhbeh.2013.08.015. Epub 2013 Sep 1.
Animals have to adapt to seasonal variations in food resources and temperature. Hibernation is one of the most efficient means used by animals to cope with harsh winter conditions, wherein survival is achieved through a significant decrease in energy expenditure. The hibernation period is constituted by a succession of torpor bouts (hypometabolism and decrease in body temperature) and periodic arousals (eumetabolism and euthermia). Some species feed during these periodic arousals, and thus show different metabolic adaptations to fat-storing species that fast throughout the hibernation period. Our study aims to define these metabolic adaptations, including hormone (insulin, glucagon, leptin, adiponectin, GLP-1, GiP) and metabolite (glucose, free fatty acids, triglycerides, urea) profiles together with body composition adjustments. Syrian hamsters were exposed to varied photoperiod and temperature conditions mimicking different phases of the hibernation cycle: a long photoperiod at 20 °C (LP20 group), a short photoperiod at 20 °C (SP20 group), and a short photoperiod at 8 °C (SP8). SP8 animals were sampled either at the beginning of a torpor bout (Torpor group) or at the beginning of a periodic arousal (Arousal group). We show that fat store mobilization in hamsters during torpor bouts is associated with decreased circulating levels of glucagon, insulin, leptin, and an increase in adiponectin. Refeeding during periodic arousals results in a decreased free fatty acid plasma concentration and an increase in glycemia and plasma incretin concentrations. Reduced incretin and increased adiponectin levels are therefore in accordance with the changes in nutrient availability and feeding behavior observed during the hibernation cycle of Syrian hamsters.
动物必须适应食物资源和温度的季节性变化。冬眠是动物应对恶劣冬季条件的最有效手段之一，通过显著降低能量消耗来实现生存。冬眠期由一系列蛰伏期（代谢率降低和体温下降）和周期性觉醒（代谢正常和体温正常）组成。一些物种在这些周期性觉醒期间进食，因此表现出与在整个冬眠期间禁食的储脂物种不同的代谢适应。我们的研究旨在定义这些代谢适应，包括激素（胰岛素、胰高血糖素、瘦素、脂联素、GLP-1、GiP）和代谢物（葡萄糖、游离脂肪酸、甘油三酯、尿素）谱以及身体成分调整。叙利亚仓鼠暴露于模拟不同冬眠周期阶段的不同光照和温度条件下：长光照 20°C（LP20 组）、短光照 20°C（SP20 组）和短光照 8°C（SP8 组）。SP8 动物在蛰伏期开始时（蛰伏组）或周期性觉醒开始时（觉醒组）采样。我们表明，在蛰伏期，仓鼠的脂肪储存动员与循环中胰高血糖素、胰岛素、瘦素水平降低和脂联素水平升高有关。周期性觉醒时进食会导致游离脂肪酸血浆浓度降低、血糖升高和血浆肠促胰岛素浓度升高。因此，降低的肠促胰岛素和增加的脂联素水平与在叙利亚仓鼠冬眠周期中观察到的营养物质可用性和进食行为的变化一致。
