Sylvie Geiger, Marion Kauffmann, Yvon Le Maho, Jean-Patrice Robin, Criscuolo Francois
Université de Strasbourg, IPHC, 23 rue Becquerel, 67087 Strasbourg, France.
Physiol Biochem Zool. 2012 Jul-Aug;85(4):415-20. doi: 10.1086/666364. Epub 2012 May 29.
Life phases such as migration or reproduction may partly (or totally) prohibit food accessibility, making regulation of the energy balance one of the main challenges faced by wild organisms. Although long-term fasting is common in a number of species, it has been reported to be detrimental for the organism, notably because it induces oxidative stress. However, fasting metabolism is characterized by successive metabolic adaptations that are likely to be different in terms of stress, and no previous studies, to our knowledge, have tested the dynamics of changes in oxidative balance in relation to the metabolic phases of fasting. Our study provides a first insight into this relationship by inducing prolonged fasting and subsequent refeeding in captive mallards (Anas platyrhynchos). Both plasmatic antioxidant and oxidative damage levels were observed to be lower during fasting. Oxidative damage levels decreased by 95% during fasting, and they surprisingly remained at low levels even after 3 d of refeeding. In contrast, restoration of the antioxidant barrier was observed from the third day of refeeding onward, and it thus preceded the increase in oxidative damage levels. Therefore, under our experimental conditions, long-term fasting was not associated with marked oxidative stress in mallards. Because data interpretations may be influenced by concomitant metabolic states, we underline the importance of taking metabolic phases into account when studying oxidative stress during fasting.
诸如迁徙或繁殖等生命阶段可能会部分（或完全）限制食物的获取，这使得能量平衡的调节成为野生生物面临的主要挑战之一。尽管长期禁食在许多物种中很常见，但据报道这对生物体是有害的，特别是因为它会诱导氧化应激。然而，禁食代谢的特点是连续的代谢适应，在应激方面可能有所不同，据我们所知，以前没有研究测试过与禁食代谢阶段相关的氧化平衡变化动态。我们的研究通过在圈养绿头鸭（Anas platyrhynchos）中诱导长期禁食和随后的重新喂食，首次深入了解了这种关系。在禁食期间，血浆抗氧化剂和氧化损伤水平均被观察到较低。禁食期间氧化损伤水平下降了95%，令人惊讶的是，即使在重新喂食3天后，它们仍保持在低水平。相比之下，从重新喂食的第三天开始观察到抗氧化屏障的恢复，因此它先于氧化损伤水平的增加。因此，在我们的实验条件下，长期禁食与绿头鸭明显的氧化应激无关。由于数据解释可能会受到伴随代谢状态的影响，我们强调在研究禁食期间的氧化应激时考虑代谢阶段的重要性。
