National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan 316022, PR China.
College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, PR China.
Ecotoxicol Environ Saf. 2019 Jun 15;174:324-333. doi: 10.1016/j.ecoenv.2019.02.088. Epub 2019 Mar 5.
The aim of the present study was to compare the differences of Zn-induced antioxidant defense, immunotoxicity and Zn homeostasis between the proximal and distal intestines of the large yellow croaker Larimichthys crocea. Fish were exposed to Zn (2 and 10 mg L) for 96 h. In the proximal intestine, high-concentration Zn increased mortality and oxidative damage, but reactive oxygen species (ROS), lipid peroxidation (LPO), protein carbonylation (PC) levels were not affected by low-concentration Zn, indicating Zn-induced oxidative damage was concentration-dependent. Antioxidant defense and immunotoxicity in response to Zn exposure may be involved in ROS/ NFE2-related nuclear factor 2 (Nrf2) and ROS/nuclear transcription factor κB (NF-κB) signaling pathways. In the distal intestine, Zn exposures did not induce oxidative damage, which may result from the improvement of Zn transport, antioxidant and immune defenses. Nrf2 was positively correlated with antioxidant-related gene in the distal intestine, but no relationship was observed between Nrf2 and CAT gene expressions in the proximal intestine. In conclusion, Zn induced toxicological effects were intestinal-region-dependent, which provided some novel insights into Zn toxicology.
本研究旨在比较大黄鱼近端和远端肠道在锌诱导的抗氧化防御、免疫毒性和锌稳态方面的差异。将鱼暴露于锌（2 和 10mg/L）中 96 小时。在近端肠道中，高浓度锌增加了死亡率和氧化损伤，但低浓度锌对活性氧（ROS）、脂质过氧化（LPO）、蛋白质羰基化（PC）水平没有影响，表明锌诱导的氧化损伤具有浓度依赖性。对锌暴露的抗氧化防御和免疫毒性可能涉及活性氧/NFE2 相关核因子 2（Nrf2）和活性氧/核转录因子 κB（NF-κB）信号通路。在远端肠道中，锌暴露没有引起氧化损伤，这可能是由于锌转运、抗氧化和免疫防御的改善所致。在远端肠道中，Nrf2 与抗氧化相关基因呈正相关，但在近端肠道中，Nrf2 与 CAT 基因表达之间没有观察到关系。总之，锌诱导的毒理学效应具有肠道区域依赖性，为锌毒理学提供了一些新的见解。
