Development and evaluation of the mallard duck as a model to investigate the immunotoxicity of environmental chemicals
Studies were conducted to characterize the mallard duck (Anas platyrhyncos) as a model for evaluating the immunotoxic effects of environmental chemicals. A battery of immunotoxicity tests was validated for the mallard, including natural killer cell (NKC) activity, lymphocyte mitogenesis, antibody titers to sheep erythrocytes, peripheral differential leukocyte counts, macrophage phagocytosis and prostaglandin-E[sub 2] (PGE2) production. To investigate potential hormonal-immune axes, dexamethasone (DEX), methimazole, and thyroxine (T4) were used to study the influence of glucocorticoid excess, hypo-, and hyperthyroidism on immunity, respectively. Subsequently, the effects of polychlorinated biphenyls (PCBs, Aroclor 1254) on immune, endocrine, and hepatic cytochrome-P450 function were evaluated and interpreted using results from the endocrine/immune studies. Results of these studies showed that antibody production was susceptible to suppression by DEX at doses which also caused significant changes in clinical plasma biochemistry values. NKC activity was enhanced by exposure to DEX in vivo, a phenomenon due to the inhibition of PGE2 production by adherent peripheral blood cells by DEX and mimicked in vitro with addition of indomethacin or DEX. Macrophage phagocytosis was significantly suppressed by DEX in vitro. Macrophage production of PGE2 ex vivo was suppressed in birds treated with DEX. In contrast to DEX, T4 or methimazole treatment elicited only slight physiologic changes in plasma albumin and cholesterol levels. No immune/thyroid axis was observed in mallards. Exposure to Aroclor 1254 induced significant hepatic microsomal ethoxy- and pentoxy-resorufin-O-deethylase activities in addition to increasing total cytochrome P450 content, but did not affect immune function, plasma corticosterone, or clinical biochemistry values. Total triiodothyronine, but not T4, was dose-dependently suppressed by PCB treatment.
- Research Organization:
- Oregon State Univ., Corvallis, OR (United States)
- OSTI ID:
- 6590597
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Induction of hepatic CYP1A in male F344/NCr rats by dietary exposure to Aroclor 1254: Examination of immunochemical, RNA, catalytic, and pharmacokinetic endpoints
Metabolic activation of carcinogenic aromatic amines by fish exposed to environmental pollutants
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
DUCKS
BIOLOGICAL MODELS
IMMUNE REACTIONS
POLYCHLORINATED BIPHENYLS
TOXICITY
IMMUNOSUPPRESSION
SENSITIVITY ANALYSIS
ANIMALS
AROMATICS
BIRDS
CHLORINATED AROMATIC HYDROCARBONS
FOWL
HALOGENATED AROMATIC HYDROCARBONS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology
550200 - Biochemistry