title: Immunosuppression without liver induction by subchronic exposure to 2,7-dichlorodibenzo-p-dioxin in adult female B6C3F1 mice.
abstract: The overall objective of this investigation was to begin to characterize the structure-activity relationship associated with dioxin-induced suppression of humoral immunity. Subchronic exposure (14 days) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the prototype of the class, produced a suppression of the antibody responses to both sheep erythrocytes, a T-dependent antigen, and dinitrophenyl-Ficoll, a T-independent antigen. Surprisingly, similar results were observed with 2,7-dichlorodibenzo-p-dioxin (DCDD), a dioxin congener lacking affinity for the Ah receptor. In contrast, subchronic exposure to octachlorodibenzo-p-dioxin (OCDD), another dioxin congener without affinity for the Ah receptor, was devoid of activity. Subchronic exposure to 2,3,7,8-TCDD, but not 2,7-DCDD, produced an induction of several liver parameters including: liver weight, amount of microsomal protein, amount of cytochrome P-450, activity of aminopyrine-N-demethylase and activity of aryl hydrocarbon hydroxylase. Subchronic exposure to 2,3,7,8-TCDD or 2,7-DCDD produced no marked changes in thymus weight. Acute exposure to 2,3,7,8-TCDD also produced suppression of the antibody response in the absence of effects on the thymus.
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D001711:Biotransformation; D001835:Body Weight / Q000187:drug effects; D004147:Dioxins / Q000378:metabolism / Q000633:toxicity*; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D007075:Immunoglobulin M / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000276:immunology; D008099:Liver / Q000187:drug effects; D051379:Mice; D008862:Microsomes, Liver / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D012756:Sheep; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000187:drug effects
chemical_list: D004147:Dioxins; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D000072317:Polychlorinated Dibenzodioxins; C000925:2,7-dichlorodibenzo-4-dioxin