Iwanowicz Luke R, Blazer Vicki S, McCormick Stephen D, Vanveld Peter A, Ottinger Christopher A
National Fish Health Research Laboratory, USGS, Leetown Science Center, Fish Health Branch, Kearneysville, WV 25430, USA. Luke
Aquat Toxicol. 2009 Jun 4;93(1):70-82. doi: 10.1016/j.aquatox.2009.03.008. Epub 2009 Apr 5.
The brown bullhead Ameiurus nebulosus is a species of the family Ictaluridae commonly used as a sentinel of environmental contamination. While these fish have been utilized for this purpose in areas contaminated with polychlorinated biphenyls (PCBs), few controlled, laboratory-based studies have been designed to document the effects of PCB mixtures in this species. Here, brown bullhead were exposed to the PCB mixture, Aroclor 1248, via intraperitoneal injection and the effects on immune function, plasma hormones and disease resistance were evaluated. Exposure to this mixture led to a decrease in bactericidal activity and circulating antibodies to Edwardsiella ictaluri present from a previous exposure to this pathogen. A subsequent E. ictaluri disease challenge led to significantly higher mortality in A1248 treated fish compared to vehicle-control fish. The mitogenic response to the T-cell mitogen, phytohemaglutinin-P, was increased compared to vehicle-control fish. The steroid hormone, cortisol, and the thyroid hormone, T3, were also significantly lower in A1248 exposed fish. In summary, we have validated a number of functional immune assays for application in brown bullhead immunotoxicity studies. Additionally, we have demonstrated that the PCB mixture (A1248) modulates both immune function and endocrine physiology in brown bullhead. Such data may compliment the interpretation of data yielded from applied field studies conducted in PCB contaminated aquatic ecosystems.
褐首鲶（Ameiurus nebulosus）是鲇科的一种鱼类，常被用作环境污染的指示生物。虽然这些鱼类已在受多氯联苯（PCBs）污染的地区用于此目的，但很少有基于实验室的对照研究旨在记录多氯联苯混合物对该物种的影响。在此，通过腹腔注射将褐首鲶暴露于多氯联苯混合物Aroclor 1248，并评估其对免疫功能、血浆激素和抗病性的影响。暴露于该混合物导致杀菌活性降低，以及先前暴露于该病原体后产生的针对鮰爱德华氏菌的循环抗体减少。随后进行的鮰爱德华氏菌疾病攻毒导致与溶剂对照鱼相比，A1248处理的鱼死亡率显著更高。与溶剂对照鱼相比，对T细胞有丝分裂原植物血凝素-P的促有丝分裂反应增强。在暴露于A1248的鱼中，类固醇激素皮质醇和甲状腺激素T3也显著降低。总之，我们已经验证了一些功能性免疫测定法可用于褐首鲶免疫毒性研究。此外，我们已经证明多氯联苯混合物（A1248）调节褐首鲶的免疫功能和内分泌生理学。这些数据可能有助于补充对在受多氯联苯污染的水生生态系统中进行的应用现场研究所得数据的解释。
