Oxidative damage and antioxidants in Rana sylvatica the freeze-tolerant wood frog
Oxidative damage and antioxidants in Rana sylvatica the freeze-tolerant wood frog
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DOI：
10.1152/ajpregu.1996.271.3.r545
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发表时间：
1996-09-01
影响因子：
2.8
通讯作者：
Storey, KB
中科院分区：
文献类型：
--
作者：
Joanisse, DR;Storey, KB
耐冻林蛙（Rana sylvatica）必须忍受长时间的冰冻缺血。由于活性氧的形成，解冻时的再灌注可能导致氧化损伤，这是哺乳动物缺血再灌注的一个众所周知的后果。为了确定在解冻过程中是否会发生氧化损伤，以及青蛙是如何应对这种情况的，我们研究了森林蛙（Rana sylvatica）和非冷冻亲缘蛙（Rana pipiens）组织中的氧化损伤、抗氧化和促氧化系统。谷胱甘肽状态表明组织在冷冻或解冻过程中氧化应激较少；在冷冻过程中，仅在林蛙肾脏（85%）和大脑（33%）中观察到氧化形式的谷胱甘肽库的增加。通过硫代巴比妥酸反应物质和/或铁（III）二甲酚橙测定来测量的组织脂质氧化损伤，在冻融时间过程中没有高于控制值的增加。相关数据显示，在冷冻过程中，某些抗氧化酶的活性增加，尤其是谷胱甘肽过氧化物酶（增加1.2- 2.5倍），以及抗氧化酶活性和谷胱甘肽水平的提高，这些都表明抗氧化防御在两栖动物的抗冻性中起着关键作用。
Freeze-tolerant wood frogs (Rana sylvatica) must endure prolonged ischemia on freezing. Reperfusion on thawing brings with it the potential for oxidative damage due to reactive oxygen species formation, a well-known consequence of mammalian ischemia-reperfusion. To determine whether oxidative damage occurs during thawing and how frogs deal with this, we examined oxidative damage and antioxidant and prooxidant systems in tissues of Rana sylvatica and a nonfreezing relative, Rana pipiens. Glutathione status indicated little oxidative stress in tissues during freezing or thawing; an increase of the glutathione pool in the oxidized form was observed during freezing only in Rana sylvatica kidney (by 85%) and brain (by 33%). Oxidative damage to tissue lipids, measured as the levels of thiobarbituric acid-reactive substances and/or by an Fe(III)xylenol orange assay, did not increase above control values over a freeze-thaw time course. Correlative data showing increased activities of some antioxidant enzymes during freezing, notably glutathione peroxidase (increasing 1.2- to 2.5-fold), as well as constitutively higher activities of antioxidant enzymes and higher levels of glutathione in the freeze-tolerant species compared with Rana pipiens, suggest that antioxidant defenses play a key role in amphibian freeze tolerance.