Wilhelm Filho Danilo, Althoff Sérgio Luiz, Dafré Alcir Luiz, Boveris Alberto
Departamento de Ecologia e Zoologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
Departamento de Ecologia e Zoologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
Comp Biochem Physiol C Toxicol Pharmacol. 2007 Jul-Aug;146(1-2):214-220. doi: 10.1016/j.cbpc.2006.11.015. Epub 2006 Dec 21.
Microchiropteran bats sustain very high oxygen consumption rates when active, but they also exhibit drastic daily drops in oxygen consumption when torpid. In addition, bats are also characterized by an extraordinary longevity considering their body mass and high specific metabolic rate when compared to other mammals of related size. Therefore, they consist of a very interesting group regarding the free radical theory of aging. The present study was carried out to measure the antioxidant defenses of several tissues of five South American bat species, attempting to correlate the antioxidant status, ecophysiology and longevity. Superoxide dismutase (SOD) and catalase (CAT) activities in blood, liver and kidney were higher compared to other tissues. The contents of alpha-tocopherol and beta-carotene found in liver, heart, kidneys, and pectoral muscles were one to two orders of magnitude higher than those usually found in rat and mouse liver. Also, these contents in liver were generally inversely related to lipoperoxidation measured as TBARS contents. Blood GSH contents and the activities of SOD and CAT were higher in torpid Sturnira lillium compared to active ones, thus suggesting that the elevation of such antioxidants might be daily modulated to minimize the oxidative stress related to the transition from torpid to active state in bats. The lower ROS generation reported in the literature for other bat species, their high constitutive antioxidant defenses, and the daily energy sparing associated with torpor appear to be closely related to their ecophysiological adaptations and to their extended longevity.
小型食虫蝙蝠在活动时维持着非常高的耗氧率，但在蛰伏时它们的耗氧量也会出现大幅的每日下降。此外，考虑到它们的体重以及与其他相关体型的哺乳动物相比具有较高的特定代谢率，蝙蝠还具有超长的寿命。因此，就衰老的自由基理论而言，它们构成了一个非常有趣的群体。本研究旨在测量五种南美蝙蝠物种几种组织的抗氧化防御能力，试图将抗氧化状态、生态生理学和寿命联系起来。与其他组织相比，血液、肝脏和肾脏中的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性更高。在肝脏、心脏、肾脏和胸肌中发现的α-生育酚和β-胡萝卜素含量比通常在大鼠和小鼠肝脏中发现的含量高1到2个数量级。此外，肝脏中的这些含量通常与以硫代巴比妥酸反应物（TBARS）含量衡量的脂质过氧化呈负相关。与活跃状态的利氏吸血蝠相比，蛰伏状态的利氏吸血蝠血液中的谷胱甘肽（GSH）含量以及SOD和CAT的活性更高，这表明此类抗氧化剂的升高可能会每日进行调节，以尽量减少与蝙蝠从蛰伏状态转变为活跃状态相关的氧化应激。文献中报道的其他蝙蝠物种较低的活性氧生成、它们较高的组成性抗氧化防御能力以及与蛰伏相关的每日能量节约，似乎与它们的生态生理适应及其延长的寿命密切相关。
