title: Aroclor 1254 as an antagonist of the teratogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin.
abstract: Administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 20 micrograms/kg) to pregnant C57BL/6J mice (on day 10) resulted in 62% fetuses with cleft palate per litter without any observable maternal toxicity. In contrast, Aroclor 1254 administered at a dose of 750 mumol/kg was not teratogenic. Cotreatment of the pregnant mice with both Aroclor 1254 (244 mg/kg) and 2,3,7,8-TCDD (20 micrograms/kg) resulted in an 8.2% incidence of cleft palate per litter. In contrast, Aroclor 1254 did not afford any protection from the teratogenicity of dexamethasone in C57BL/6J mice. Previous studies have shown that Aroclor 1254 can act as a partial antagonist of the microsomal enzyme induction and immunotoxic effects of 2,3,7,8-TCDD in C57BL/6J mice and this paper demonstrates that the commercial polychlorinated biphenyl mixture also antagonizes 2,3,7,8-TCDD-mediated teratogenicity in this strain of mice.
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station 77843.
authors.forename: J M
authors.initials: JM
authors.lastname: Haake
authors.forename: S
authors.initials: S
authors.lastname: Safe
authors.forename: K
authors.initials: K
authors.lastname: Mayura
authors.forename: T D
authors.initials: TD
authors.lastname: Phillips
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology* / Q000517:prevention & control; D000818:Animals; D001140:Aroclors / Q000494:pharmacology*; D020111:Chlorodiphenyl (54% Chlorine); D002972:Cleft Palate / Q000139:chemically induced* / Q000517:prevention & control; D003907:Dexamethasone / Q000633:toxicity; D004147:Dioxins / Q000037:antagonists & inhibitors*; D004347:Drug Interactions; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D011078:Polychlorinated Biphenyls / Q000494:pharmacology*; D000072317:Polychlorinated Dibenzodioxins / Q000037:antagonists & inhibitors* / Q000633:toxicity; D011247:Pregnancy; D018336:Receptors, Aryl Hydrocarbon; D011955:Receptors, Drug / Q000187:drug effects
chemical_list: D001140:Aroclors; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D011955:Receptors, Drug; D020111:Chlorodiphenyl (54% Chlorine); D003907:Dexamethasone; D011078:Polychlorinated Biphenyls