Alonso-Alvarez Carlos, Pérez-Rodríguez Lorenzo, García Jesus T, Viñuela Javier, Mateo Rafael
Instituto de Investigación en Recursos Cinegéticos (Consejo Superior de Investigaciones Científicas, Universidad de Castilla-La Mancha, Junta de Communidades de Castilla-La Mancha), Ronda de Toledo, s/n. 13071, Ciudad Real, Spain.
Physiol Biochem Zool. 2010 Jan-Feb;83(1):110-8. doi: 10.1086/605395.
Oxidative stress is the imbalance between the production of pro-oxidant substances and the level of antioxidant defenses, which leads to oxidative damage. It has been proposed that senescence is the result of accumulated oxidative damage throughout life. In birds, the sources of individual variability in oxidative stress are still poorly understood. Among these sources, age, as related to senescence, should be particularly relevant. Furthermore, recent findings suggest that breeding effort may also deeply influence susceptibility to oxidative stress. However, there is still no evidence of a link between breeding effort and oxidative damage in any vertebrate. Here we analyzed 288 captive red-legged partridges (Alectoris rufa) across a wide age range (i.e., 1-8 yr old), thus including potentially senescent birds. In spite of limitations due to the cross-sectional approach, results revealed that old birds produced less offspring and endured higher levels of oxidized glutathione and peroxidized lipids in erythrocytes than did middle-aged individuals. Old birds also showed higher plasma total antioxidant status and uric acid levels than did younger birds, but lower amounts of circulating carotenoids. Furthermore, hatching success was negatively correlated to lipid peroxidation in females but not in males, supporting the hypothesis that breeding effort promotes oxidative damage.
氧化应激是促氧化物质的产生与抗氧化防御水平之间的失衡，这会导致氧化损伤。有人提出衰老乃是一生中累积的氧化损伤的结果。在鸟类中，氧化应激个体差异的来源仍知之甚少。在这些来源中，与衰老相关的年龄应该尤为重要。此外，最近的研究结果表明繁殖投入也可能深刻影响对氧化应激的易感性。然而，尚无证据表明在任何脊椎动物中繁殖投入与氧化损伤之间存在关联。在此，我们分析了288只圈养的红腿鹧鸪（石鸡），其年龄范围很广（即1至8岁），因此包括了可能衰老的鸟类。尽管横断面研究方法存在局限性，但结果显示，与中年个体相比，老年鸟类产仔较少，且红细胞中氧化型谷胱甘肽和过氧化脂质水平更高。老年鸟类的血浆总抗氧化状态和尿酸水平也高于年轻鸟类，但循环类胡萝卜素的含量较低。此外，孵化成功率与雌性而非雄性的脂质过氧化呈负相关，这支持了繁殖投入会促进氧化损伤的假说。
