Water deprivation induces appetite and alters metabolic strategy in Notomys alexis: unique mechanisms for water production in the desert
Water deprivation induces appetite and alters metabolic strategy in Notomys alexis: unique mechanisms for water production in the desert
复制标题
DOI：
10.1098/rspb.2011.2627
复制
发表时间：
2012-07-07
影响因子：
4.7
通讯作者：
Donald, John A.
中科院分区：
文献类型：
--
作者：
Takei, Yoshio;Bartolo, Ray C.;Donald, John A.
像许多沙漠动物一样，刺跳鼠（Notomys alexis）可以在不喝水的情况下保持水分平衡。肾脏在产生少量高浓度尿液中的作用已被充分证明，但对代谢产生水以抵消必要水分损失的生理机制知之甚少。在Notomys中，我们发现缺水（WD）诱导了持续的高食物摄入量，超过了缺水前的水平，这是由血浆瘦素和胃饥饿素以及下丘脑中厌氧和厌食神经肽基因表达的平行变化驱动的；这些变化的方向会刺激食欲。随着WD时间的延长，体脂逐渐消失，体重逐渐增加，这与肝糖原储存有关。将代谢策略从脂质转换为碳水化合物将提高每个氧分子的代谢水产量，从而提供一种减少呼吸水分损失的机制。在实验小鼠中，Notomys在食欲控制和代谢策略方面所观察到的变化不存在或不太明显。这项研究揭示了食欲调节和能量代谢的新机制，这可能是沙漠啮齿动物在干旱环境中生存所必需的。
Like many desert animals, the spinifex hopping mouse, Notomys alexis, can maintain water balance without drinking water. The role of the kidney in producing a small volume of highly concentrated urine has been well-documented, but little is known about the physiological mechanisms underpinning the metabolic production of water to offset obligatory water loss. In Notomys, we found that water deprivation (WD) induced a sustained high food intake that exceeded the pre-deprivation level, which was driven by parallel changes in plasma leptin and ghrelin and the expression of orexigenic and anorectic neuropeptide genes in the hypothalamus; these changed in a direction that would stimulate appetite. As the period of WD was prolonged, body fat disappeared but body mass increased gradually, which was attributed to hepatic glycogen storage. Switching metabolic strategy from lipids to carbohydrates would enhance metabolic water production per oxygen molecule, thus providing a mechanism to minimize respiratory water loss. The changes observed in appetite control and metabolic strategy in Notomys were absent or less prominent in laboratory mice. This study reveals novel mechanisms for appetite regulation and energy metabolism that could be essential for desert rodents to survive in xeric environments.