Different effects of low- and high-dose waterborne zinc on Zn accumulation, ROS levels, oxidative damage and antioxidant responses in the liver of large yellow croaker Pseudosciaena crocea

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• 作者：Jia-Lang Zheng ; Lin Zeng ; Mei-Ying Xu ; Bin Shen…
• 关键词：Waterborne zinc ; Antioxidant response ; Zn accumulation ; Large yellow croaker
• 刊名：Fish Physiology and Biochemistry
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：43
• 期：1
• 页码：153-163
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Freshwater & Marine Ecology; Animal Physiology; Animal Anatomy / Morphology / Histology; Animal Biochemistry; Zoology;
• 出版者：Springer Netherlands
• ISSN：1573-5168
• 卷排序：43

文摘

The aim of the present study was to assess survival rate, Zn accumulation, reactive oxygen species (ROS) levels, oxidative damage and antioxidant responses after Zn exposure (2 and 8 mg L−1 Zn) at different exposure times (6, 12, 24, 48 and 96 h) in the liver of large yellow croaker. Survival rate was reduced at 96 h, and hepatic Zn content increased during 24–96 by 8 mg L−1 Zn. In the 2 mg L−1 Zn group, no fish died and the increase in Zn content merely occurred at 96 h. Exposure to 8 mg L−1 Zn induced accumulation of ROS, lipid peroxidation and protein carbonylation during the late stage of exposure. In contrast, exposure to 2 mg L−1 Zn did not result in oxidative damage, which may result from the up-regulation of antioxidant defenses. Although exposure to 8 mg L−1 Zn increased activities and mRNA levels of antioxidant enzymes during the early stage of exposure, including Cu/Zn–SOD, Mn–SOD, CAT, GPx and GR, the activities of these enzymes except Cu/Zn–SOD were inhibited at 96 h. Furthermore, a sharp increase in Nrf2 expression was observed in fish exposed to 8 mg L−1 at 6 and 12 h, and 2 mg L−1 at 12 h and 24 h, suggesting that Nrf2 was required for the protracted induction of these genes. The late increase in Keap1 expression may support its role in switching off the Nrf2 response. In conclusion, the present study demonstrated different effects of low- and high-dose waterborne Zn on antioxidant responses, which could contribute to the understanding of antioxidant and toxic roles of zinc on a molecular level.