Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan; Department of Biomedical Sciences, School of Veterinary Medicine, The University of Zambia, P. O. Box 32379, Lusaka, Zambia.
Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan; Water Research Group, Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom, South Africa.
Aquat Toxicol. 2020 Oct;227:105607. doi: 10.1016/j.aquatox.2020.105607. Epub 2020 Aug 19.
The ubiquitous contamination of environmental lead (Pb) remains a worldwide threat. Improper Pb mine waste disposal from an abandoned lead-zinc mine has recently unearthed widespread Pb poisoning in children in Kabwe Zambia. Although the adverse effects of Pb on human health have begun to receive attention, the ecotoxicological effects on aquatic vertebrates still need further investigation. In addition, there is paucity in the knowledge on the behavioural and molecular subcellular responses in larval zebrafish exposed to Pb within the range of environmental relevant concentration (average 3 μg/L with maximum of 94 μg/L) on aquatic organisms such as zebrafish. The adverse effects of environmentally relevant levels of Pb on larval zebrafish was evaluated by measuring swimming behaviour under alternating dark and light conditions. Larval zebrafish acutely exposed to environmentally relevant Pb exhibited neuro-behavioural alteration including enhanced hyperactivity under light conditions evidenced by increased distanced covered and speed compared to the control. The alteration of entire behavioral profiles was further associated with the disturbed expression patterns of mRNA level of key genes associated with antioxidant (HO-1, Ucp-2 and CoxI), proapoptotic gene (TP53), and antiapoptotic gene (Bcl-2). To our knowledge, this is the first report on the effects of environmentally relevant Pb levels from Kabwe, Zambia and their adverse neurobehavioural effects and subcellular molecular oxidative responses in larval zebrafish acutely exposed within a 30 min period. The current results would be beneficial in our understanding of the effects of low Pb levels acutely discharged into an aquatic environment and the life of aquatic organisms.
环境铅（Pb）的普遍污染仍然是一个全球性的威胁。赞比亚卡布韦市一个废弃的铅锌矿最近发现了大量儿童铅中毒事件，原因是矿渣处理不当。尽管 Pb 对人类健康的不良影响已开始受到关注，但对水生脊椎动物的生态毒理学影响仍需进一步研究。此外，对于在环境相关浓度范围内（平均 3μg/L，最高 94μg/L）暴露于 Pb 的幼鱼的行为和分子亚细胞反应的知识仍然匮乏。在环境相关浓度范围内，通过测量在明暗交替条件下的游泳行为来评估 Pb 对幼鱼的不良影响。急性暴露于环境相关 Pb 的幼鱼表现出神经行为改变，包括在光照条件下的过度活跃增强，与对照组相比，游动距离和速度增加。整个行为谱的改变进一步与关键基因的 mRNA 水平表达模式的紊乱相关联，这些关键基因与抗氧化（HO-1、Ucp-2 和 CoxI）、促凋亡基因（TP53）和抗凋亡基因（Bcl-2）有关。据我们所知，这是首次报道赞比亚卡布韦市环境相关 Pb 水平及其对幼鱼的神经行为和亚细胞分子氧化反应的不良影响，幼鱼在 30 分钟内急性暴露于该 Pb 水平。目前的结果有助于我们了解低水平 Pb 急性排放到水生环境中对水生生物的影响和水生生物的生存。
