Abstract：
With climate change increasing not just mean temperatures but the frequency of cold snaps and heat waves, animals occupying thermally variable areas may be faced with thermal conditions for which they are not prepared. Studies of physiological adaptations of temperate resident birds to such thermal variability are largely lacking in the literature. To address this gap, we acclimated winter-phenotype house sparrows (Passer domesticus) to stable warm, stable cold, and fluctuating cold temperatures. We then measured several metrics of the oxidative stress (OS) system, including enzymatic and non-enzymatic antioxidants and lipid oxidative damage, in brain (post-mitotic), kidney (mitotic), liver (mitotic) and pectoralis muscle (post-mitotic). We predicted that high metabolic flexibility could be linked to increases in reactive oxygen damage. Alternatively, if variation in ROS production is not associated with metabolic flexibility, then we predict no antioxidant compensation with thermal variation. Our data suggest that ROS production is not associated with metabolic flexibility, as we found no differences across thermal treatment groups. However, we did find differences across tissues. Brain catalase activity demonstrated the lowest values compared with kidney, liver and muscle. In contrast, brain glutathione peroxidase (GPx) activities were higher than those in kidney and liver. Muscle GPx activities were intermediate to brain and kidney/liver. Lipid peroxidation damage was lowest in the kidney and highest in muscle tissue.
摘要：
随着气候变化不仅增加了平均温度，而且增加了寒流和热浪的频率，占据热可变区域的动物可能面临他们没有准备好的热条件。文献中缺乏对温带常驻鸟类对这种热变异性的生理适应的研究。为了解决这个差距，我们使冬季表型的麻雀（Passerdomesticus）适应了稳定的温暖，稳定的寒冷，和寒冷的温度波动。然后我们测量了氧化应激(OS)系统的几个指标，包括酶和非酶抗氧化剂和脂质氧化损伤，在大脑中（有丝分裂后），肾（有丝分裂），肝脏（有丝分裂）和胸肌（有丝分裂后）。我们预测，高代谢灵活性可能与活性氧损伤的增加有关。或者，如果ROS产生的变化与代谢灵活性无关，然后我们预测没有抗氧化剂补偿与热变化。我们的数据表明，ROS的产生与代谢灵活性无关，因为我们发现热疗组之间没有差异。然而,我们确实发现了不同组织的差异。与肾脏相比，脑过氧化氢酶活性最低，肝脏和肌肉。相比之下,脑谷胱甘肽过氧化物酶（GPx）活性高于肾脏和肝脏。肌肉GPx活性在脑和肾/肝中间。脂质过氧化损害在肾脏中最低，在肌肉组织中最高。
