Department of Analytical and Applied Chemistry, School of Engineering, Institut Químic de Sarrià-Universitat Ramon Llull, 08017 Barcelona, Spain.
proCURE, Catalan Institute of Oncology (ICO), Oncobell, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.
Sci Total Environ. 2024 Feb 20;912:169301. doi: 10.1016/j.scitotenv.2023.169301. Epub 2023 Dec 14.
The current view is that environmental levels of nicotine and cotinine, commonly in the ng/L range, are safe for aquatic organisms. In this study, 7 days post-fertilization zebrafish embryos have been exposed for 24 h to a range of environmental concentrations of nicotine (2.0 ng/L-2.5 μg/L) and cotinine (50 pg/L-10 μg/L), as well as to a binary mixture of these emerging pollutants. Nicotine exposure led to hyperactivity, decreased vibrational startle response and increased non-associative learning. However, the more consistent effect found for both nicotine and cotinine was a significant increase in light-off visual motor response (VMR). The effect of both pollutants on this behavior occurred through a similar mode of action, as the joint effects of the binary mixture of both chemicals were consistent with the concentration addition concept predictions. The results from docking studies suggest that the effect of nicotine and cotinine on light-off VMR could be mediated by zebrafish α7 nAChR expressed in retina. The results presented in this study emphasize the need to revisit the environmental risk assessment of chemicals including additional ecologically relevant sublethal endpoints.
目前的观点认为，环境尼古丁和可替宁水平（通常在纳克/升范围内）对水生生物是安全的。在这项研究中，受精后 7 天的斑马鱼胚胎在 24 小时内暴露于一系列环境浓度的尼古丁（2.0 纳克/升-2.5 微克/升）和可替宁（50 皮克/升-10 微克/升），以及这些新兴污染物的二元混合物中。尼古丁暴露导致过度活跃、振动性惊跳反应降低和非联想性学习增加。然而，尼古丁和可替宁都发现了更一致的影响，即光暗视觉运动反应（VMR）显著增加。这两种污染物对这种行为的影响是通过类似的作用模式发生的，因为这两种化学物质的二元混合物的联合效应与浓度加和概念预测一致。对接研究的结果表明，尼古丁和可替宁对光暗 VMR 的影响可能是由视网膜中表达的斑马鱼α7 nAChR 介导的。本研究的结果强调需要重新评估包括额外的生态相关亚致死终点在内的化学物质的环境风险评估。
