Birds sacrifice oxidative protection for reproduction
Birds sacrifice oxidative protection for reproduction
复制标题
鸟类为了繁殖而牺牲氧化保护
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
S. Verhulst
中科院分区：
文献类型：
--
作者：
P. Wiersma;C. Selman;J. Speakman;S. Verhulst
氧化代谢不可避免地产生活性氧（ROS），ROS对DNA、蛋白质和脂质的损伤被认为是衰老的主要因素。增加生殖努力会加速衰老，但生殖努力是否以牺牲对氧化损伤的保护为代价而增加尚未得到验证。我们操纵繁殖努力斑胸草雀通过育雏大小操纵和测量两个主要的抗氧化酶（超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GPx）的活性在胸肌后19-20天的育雏饲养。氧化应激反映了氧化保护和ROS暴露之间的平衡，因此，我们将SOD和GPx活性与每日能量消耗（DEE）作为ROS产生的指标。SOD和GPx活性随育雏数的增加分别下降28%和24%。这种效果是相同的，在两种性别，但出现在不同的方式：男性没有改变他们的DEE，但有较低的绝对酶活性，和女性增加他们的DEE，但没有改变绝对酶活性。这一结果表明，衰老加速增加生殖努力至少部分介导的氧化应激。
Oxidative metabolism has reactive oxygen species (ROS) as unavoidable by–products, and the damage ROS inflicts on DNA, proteins and lipids is considered to be a major agent of senescence. Increasing reproductive effort accelerates senescence, but whether reproductive effort is increased at the expense of protection against oxidative damage has not yet been tested. We manipulated reproductive effort in zebra finches through brood size manipulation and measured the activity of two major antioxidant enzymes (superoxide dismutase (SOD) and glutathione peroxidase (GPx)) in the pectoral muscle after 19–20 days of brood rearing. Oxidative stress is reflected by the balance between oxidative protection and ROS exposure, and we therefore scaled SOD and GPx activity to daily energy expenditure (DEE) as an index of ROS production. SOD and GPx activity decreased with increasing brood size by 28% and 24%, respectively. This effect was identical in the two sexes, but arose in different ways: males did not change their DEE, but had lower absolute enzyme activity, and females increased their DEE, but did not change absolute enzyme activity. This result suggests that senescence acceleration by increased reproductive effort is at least in part mediated by oxidative stress.