Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
Environ Toxicol Chem. 2012 Oct;31(10):2281-8. doi: 10.1002/etc.1948. Epub 2012 Aug 9.
The modulation of Cu effects on olfactory-mediated behaviors by dissolved organic carbon (DOC) and Fe was examined in juvenile chinook salmon. Chinook were exposed to several concentrations of Cu, DOC, and Fe alone or in combination in a flow-through system for either 4 d (acute exposure) or 14 d (subchronic exposure) and tested for their ability to detect and avoid the odorant L-histidine in an avoidance/preference trough assay. In both acute and subchronic exposures, Cu inhibited the ability of fish to detect this amino acid in a concentration-dependent manner, and Cu toxicity (olfactory inhibition) decreased with increasing DOC concentration. In both acute and subchronic experiments including DOC, Cu-induced olfactory inhibition decreased in a linear fashion with increasing DOC concentration, although the modulation was lower in subchronic exposures. The protective effect of DOC on Cu olfactory inhibition was reduced only slightly in the presence of Fe, indicating that other metals can potentially affect the modulation of the olfactory inhibition of Cu through competition for DOC binding sites. The results of the present study clearly show the amelioration by DOC of the effects of Cu on juvenile chinook salmon olfaction at a behavioral level. These data further indicate that DOC concentrations should be considered when evaluating the potential impact of Cu on fish olfaction.
研究了溶解有机碳（DOC）和铁（Fe）对铜（Cu）影响嗅觉介导行为的调节作用，研究对象为幼三文鱼。在流动系统中，幼三文鱼分别单独或组合暴露于几种 Cu、DOC 和 Fe 浓度下 4 天（急性暴露）或 14 天（亚慢性暴露），然后在回避/偏好水槽试验中测试它们检测和回避 L-组氨酸这种气味剂的能力。在急性和亚慢性暴露中，Cu 均以浓度依赖的方式抑制鱼类检测这种氨基酸的能力，且 Cu 毒性（嗅觉抑制）随 DOC 浓度的增加而降低。在包括 DOC 的急性和亚慢性实验中，Cu 诱导的嗅觉抑制随 DOC 浓度的增加呈线性下降，尽管在亚慢性暴露中，这种调节作用较低。DOC 对 Cu 嗅觉抑制的保护作用在 Fe 存在的情况下仅略有降低，这表明其他金属可能通过竞争 DOC 结合位点，从而潜在地影响 Cu 嗅觉抑制的调节。本研究的结果清楚地表明，DOC 可减轻 Cu 对幼三文鱼嗅觉的影响，达到行为层面的改善效果。这些数据进一步表明，在评估 Cu 对鱼类嗅觉的潜在影响时，应考虑 DOC 浓度。
