Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus

• Published in: Aquatic toxicology Vol. 93; no. 1; pp. 70 - 82
• Main Authors: Iwanowicz, Luke R., Blazer, Vicki S., McCormick, Stephen D., VanVeld, Peter A., Ottinger, Christopher A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04-06-2009; Amsterdam; New York: Elsevier Science; Elsevier
• Subjects: Agnatha. Pisces; AhR; Ameiurus nebulosus; Animal, plant and microbial ecology; Animals; Antibodies, Bacterial - blood; Applied ecology; Aroclor; Aroclors - toxicity; bacterial infections; Bactericidal; bioassays; Bioindicators; Biological and medical sciences; Biomarker; biomarkers; Brown bullhead; Cytochrome P-450 CYP1A1 - metabolism; cytotoxicity; disease resistance; Ecotoxicology, biological effects of pollution; Edwardsiella ictaluri; Edwardsiella ictaluri - immunology; Effects of pollution and side effects of pesticides on vertebrates; Endocrine disruption; endocrine-disrupting chemicals; Enterobacteriaceae Infections - blood; Enterobacteriaceae Infections - immunology; Enterobacteriaceae Infections - microbiology; Enzyme-Linked Immunosorbent Assay; Estradiol - blood; Fish; Fish Diseases - blood; Fish Diseases - immunology; Fish Diseases - microbiology; Freshwater; freshwater fish; Fundamental and applied biological sciences. Psychology; Ictaluridae; Ictaluridae - blood; Ictaluridae - immunology; Immunomodulation; immunomodulators; immunotoxicity; indicator species; Kidney - drug effects; Kidney - immunology; Leukocytes, Mononuclear - drug effects; Leukocytes, Mononuclear - immunology; Mitogenesis; Mitogens; Muramidase - blood; PCB; polychlorinated biphenyls; Random Allocation; Respiratory Burst; Testosterone - blood; Thyroid; Thyroxine - blood; Triiodothyronine - blood; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Water Pollutants, Chemical - toxicity; water pollution; Aroclor; Biomarker; Immunomodulation; Ameiurus nebulosus; Endocrine disruption; AhR; Brown bullhead; PCB; Edwardsiella ictaluri; Bactericidal; Mitogenesis; Fish; Bioindicators; Thyroid; Animal model; Disease; Toxicity; Biological marker; Freshwater environment; Aquatic environment; Pisces; Bacteria; Enterobacteriaceae; Edwardsiella; Immune response; Ecotoxicology; Polychlorobiphenyls; Biological indicator; Ictalurus nebulosus; Endocrine disruptor; Pollutant; Vertebrata; Sensitivity resistance
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2009.03.008

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.