Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.
Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.
Mar Pollut Bull. 2017 Nov 30;124(2):710-713. doi: 10.1016/j.marpolbul.2016.12.060. Epub 2017 Jan 4.
To develop a test for assessing the immunomodulatory effects of chemical pollutants on fish, we evaluated the effects of dexamethasone on the natural host-pathogen interaction between common carp (Cyprinus carpio) and Aeromonas salmonicida. Carp were exposed to 1mgL dexamethasone for the entire experimental period. One week after the exposure test started, the exposed fish, as well as unexposed fish, were bath-infected with A. salmonicida. One hundred percent mortality was observed in bacteria-infected fish exposed to dexamethasone, whereas no infection-associated mortality was observed in infected fish in the absence of dexamethasone exposure. In a separate experiment, dexamethasone exposure significantly suppressed hemolytic complement activity in bacteria-infected fish. These results clearly indicate that exposure to a high concentration of dexamethasone suppressed the carp immune system and caused subsequent mortality. Thus, this proposed test method is likely to be useful for evaluating the immunomodulatory effects of chemicals in fish.
为了开发一种用于评估化学污染物对鱼类免疫调节作用的测试方法，我们评估了地塞米松对鲤鱼（Cyprinus carpio）和嗜水气单胞菌之间天然宿主-病原体相互作用的影响。鲤鱼在整个实验期间暴露于 1mg/L 的地塞米松中。暴露试验开始一周后，暴露和未暴露的鱼均用嗜水气单胞菌进行浴感染。在暴露于地塞米松的细菌感染鱼中观察到 100%的死亡率，而在未暴露于地塞米松的感染鱼中未观察到感染相关的死亡率。在单独的实验中，地塞米松暴露显著抑制了细菌感染鱼的溶血补体活性。这些结果清楚地表明，暴露于高浓度的地塞米松抑制了鲤鱼的免疫系统并导致随后的死亡。因此，这种拟议的测试方法可能有助于评估化学物质对鱼类的免疫调节作用。
