Shelley Lesley K, Balfry Shannon K, Ross Peter S, Kennedy Christopher J
Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.
Aquat Toxicol. 2009 Apr 9;92(2):95-103. doi: 10.1016/j.aquatox.2009.01.005. Epub 2009 Feb 23.
Many current-use pesticides (CUPs) are found at increasing concentrations in aquatic environments, yet relatively little is known about their effects on the immune system of fish. We examined the in vivo effects of three pesticides (chlorothalonil, cypermethrin and pentachlorophenol) on the immune system of juvenile rainbow trout (Oncorhynchus mykiss) by assessing a suite of innate immune function tests, as well as a host resistance test using Listonella anguillarum. Increased activity of phagocytic leukocytes, as evidenced using flow cytometry, was observed following 28-day exposures to pentachlorophenol (1 microg/L and 2 microg/L), but not for cypermethrin or chlorothalonil, although a trend of increasing activity was noted for chlorothalonil. No recovery was observed during a 14-day post-exposure chlorothalonil experiment, as evidenced by continued elevation of respiratory burst and percent phagocytic cells at the lowest exposure concentrations (100 ng/L and 200 ng/L), suggesting a prolonged CUP-induced impact on the immune system. No effects of any pesticide on body weights, direct lethality, serum lysozyme or relative leukocyte differential were observed, suggesting that modulation of the cellular responses of the innate immune system represents a sensitive sub-lethal endpoint for these three pesticides. However, a lack of detectable effects of these CUPs on host resistance to L. anguillarum in our study may reflect a dose-response range that did not elicit an effect on those immune responses responsible for control and clearance of this particular pathogen. Additional research may provide more insight into the immunomodulatory effects of these and other CUPs, and the implications for host resistance against a variety of bacterial, viral and macroparasitic pathogens.
许多目前正在使用的农药（CUPs）在水生环境中的浓度不断增加，但人们对它们对鱼类免疫系统的影响知之甚少。我们通过评估一系列先天免疫功能测试以及使用鳗弧菌进行宿主抗性测试，研究了三种农药（百菌清、氯氰菊酯和五氯苯酚）对幼年虹鳟（Oncorhynchus mykiss）免疫系统的体内影响。在暴露于五氯苯酚（1微克/升和2微克/升）28天后，通过流式细胞术观察到吞噬性白细胞的活性增加，但氯氰菊酯或百菌清未观察到这种情况，不过百菌清有活性增加的趋势。在暴露后14天的百菌清实验中未观察到恢复，最低暴露浓度（100纳克/升和200纳克/升）下呼吸爆发和吞噬细胞百分比持续升高证明了这一点，这表明CUPs对免疫系统有长期影响。未观察到任何农药对体重、直接致死率、血清溶菌酶或相对白细胞分类有影响，这表明先天免疫系统细胞反应的调节是这三种农药敏感的亚致死终点。然而，在我们的研究中这些CUPs对宿主抵抗鳗弧菌缺乏可检测到的影响，可能反映了剂量反应范围未对负责控制和清除这种特定病原体的免疫反应产生影响。更多研究可能会更深入了解这些和其他CUPs的免疫调节作用，以及对宿主抵抗各种细菌、病毒和大型寄生虫病原体的影响。
