Finger John W, Botero Juan, Zhang Yufeng, Still Shelby E, Hoffman Alexander J, Kavazis Andreas N, Cristol Daniel A, Wada Haruka
Department of Biological Sciences, Auburn University, Auburn, AL, 36849, USA.
Department of Biology, College of William & Mary, Williamsburg, VA, 23185, USA.
Bull Environ Contam Toxicol. 2017 Dec;99(6):668-672. doi: 10.1007/s00128-017-2202-7. Epub 2017 Oct 27.
Songbirds exposed to methylmercury (MeHg) often exhibit reduced reproductive success and cognitive abilities. To better understand whether oxidative stress plays a role, we dosed zebra finches (Taeniopygia guttata) with a contaminated (1.2 ppm MeHg-cysteine) or control diet for their entire lives, including during development in the egg. Levels of antioxidant enzymes [superoxide dismutase (SOD1 and SOD2)], oxidative damage (4-hydroxynonenal; 4-HNE), and antioxidant transcription factors [nuclear factor (erythroid-derived 2)-like 2; Nrf2] were measured in the liver and pectoralis muscle of adults. MeHg treatment did not affect levels of 4-HNE or liver SOD2 or Nrf2. Birds in the MeHg treatment differed significantly from controls in pectoralis SOD1 and Nrf2, and tended to differ in liver SOD1 and pectoralis SOD2; however, we detected no overall pattern of effect of MeHg on oxidative status in dosed finches. We suspect that this is a consequence of the differential survival of MeHg-tolerant birds.
接触甲基汞（MeHg）的鸣禽通常繁殖成功率和认知能力会降低。为了更好地了解氧化应激是否起作用，我们在斑胸草雀（Taeniopygia guttata）的整个生命周期，包括在卵中发育期间，给它们喂食受污染的（1.2 ppm MeHg-半胱氨酸）或对照饮食。在成年鸟的肝脏和胸肌中测量了抗氧化酶[超氧化物歧化酶（SOD1和SOD2）]水平、氧化损伤（4-羟基壬烯醛；4-HNE）以及抗氧化转录因子[核因子（红系衍生2）样2；Nrf2]水平。MeHg处理不影响4-HNE水平、肝脏SOD2或Nrf2。MeHg处理组的鸟在胸肌SOD1和Nrf2方面与对照组有显著差异，在肝脏SOD1和胸肌SOD2方面也有差异趋势；然而，我们未检测到MeHg对喂食雀类氧化状态的总体影响模式。我们怀疑这是耐MeHg鸟类差异存活的结果。
