Metabolic cycles in a circannual hibernator
Metabolic cycles in a circannual hibernator
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DOI：
10.1152/physiolgenomics.00028.2011
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发表时间：
2011-07-01
影响因子：
4.6
通讯作者：
Martin, Sandra L.
中科院分区：
文献类型：
--
作者：
Epperson, L. Elaine;Karimpour-Fard, Anis;Martin, Sandra L.
地松鼠的冬眠可以说是哺乳动物中最具可塑性和极端的生理表型。体内平衡受到长期禁食伴随着异温的挑战，但必须促进生存。我们进行了LC和GC-MS代谢组学分析的血浆样品可重复地采取在7个自然阶段的冬眠的一年，3个在夏季和4个在冬季（每个n >= 5），采用非靶向的方法来定义与表型相关的代谢物的变化。我们量化了231种命名的代谢物;其中106种发生了显着变化，在一个周期内划分了一个周期，其中在季节周期的冬季部分，torpor-arousal周期复发。确定了许多随季节和冬季阶段而改变的稳健的冬眠生物标志物，包括特定的游离脂肪酸，抗氧化剂和以前未发表的可能与禁食状态相关的修饰氨基酸。代谢物水平的主要模式是在麻痹期间消耗或增加，然后通过间歇唤醒逆转到明显的稳态水平。这一发现提供了新的数据，有力地支持了一个长期存在的假设，即周期性唤醒是恢复代谢稳态所必需的。
Hibernation as manifested in ground squirrels is arguably the most plastic and extreme of physiological phenotypes in mammals. Homeostasis is challenged by prolonged fasting accompanied by heterothermy, yet must be facilitated for survival. We performed LC and GC-MS metabolomic profiling of plasma samples taken reproducibly during seven natural stages of the hibernator's year, three in summer and four in winter (each n >= 5), employing a nontargeted approach to define the metabolite shifts associated with the phenotype. We quantified 231 named metabolites; 106 of these altered significantly, demarcating a cycle within a cycle where torpor-arousal cycles recur during the winter portion of the seasonal cycle. A number of robust hibernation biomarkers that alter with season and winter stage are identified, including specific free fatty acids, antioxidants, and previously unpublished modified amino acids that are likely to be associated with the fasting state. The major pattern in metabolite levels is one of either depletion or accrual during torpor, followed by reversal to an apparent homeostatic level by interbout arousal. This finding provides new data that strongly support the predictions of a long-standing hypothesis that periodic arousals are necessary to restore metabolic homeostasis.