The ecology of oxidative stress in bats

氧化应激是促氧化剂和抗氧化剂之间的不平衡，会对细胞造成分子损伤，被认为是衰老的主要原因。由于促氧化剂的产生随着质量比代谢率的增加而增加，具有较高代谢率的动物应该表现出较短的寿命。然而，两种脊椎动物--鸟类和蝙蝠--是这一普遍规律的例外。这两个类群的促氧化剂产生率都很低，而血浆中的抗氧化剂水平很高，这种模式被认为与它们相对较长的寿命有关。虽然已经发现抗氧化剂水平主要受饮食的影响，但随着免疫反应和高寄生虫负荷的增加，促氧化剂可能会增加。这项研究的目的是阐明饮食、寄生虫负荷和免疫状态对自由放养哺乳动物氧化应激的影响。我想用蝙蝠作为这个目的的模式生物，因为考虑到它们的物种丰富性和生态多样性，它们是比较研究的理想对象。通过测量不同新热带和欧洲蝙蝠物种血浆中的促氧化剂和抗氧化剂水平，我希望阐明影响自由放养哺乳动物氧化应激的因素，以及尚未回答的问题：轻微的氧化应激是否导致蝙蝠长寿。

Oxidative stress, an imbalance between pro-oxidants and antioxidants causing molecular damage to cells, is regarded as the main cause of ageing. As pro-oxidant production increases with mass-specific metabolic rates, animals with higher rates should exhibit shorter life spans. However, two vertebrate groups, birds and bats, are an exception to this general rule. Both taxa have low pro-oxidant production rates and high antioxidant levels in blood plasma, a pattern that was suggested to relate to their relatively longer life spans. While antioxidant levels have been found to be influenced mainly by diet, pro-oxidants may increase with immune responses and high parasite loads. The goal of this study is to elucidate the effect of diet, parasite load and immune status on the oxidative stress of free-ranging mammals. I would like to use bats as model organisms for this purpose, because they are ideal for comparative studies considering their species richness and their ecological diversity. By measuring pro-oxidant and antioxidant levels in blood plasma of various Neotropical and European bat species, I hope to shed light on the factors influencing the oxidative stress of free-ranging mammals, and on the yet unanswered question whether a mild oxidative stress is responsible for the longevity of bats.