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Main Title Interactive Regulation of Ah and Glucocorticoid Receptors in the Synergistic Induction of Cleft Palate by 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Hydrocortisone.
Author Abbott, B. D. ; Perdew, G. H. ; Buckalew, A. R. ; Birnbaum, L. S. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC. Perinatal Toxicology Branch. ;Purdue Univ., Lafayette, IN. Dept. of Foods and Nutrition. ;ManTech Environmental Technology, Inc., Research Triangle Park, NC.
Publisher c1994
Year Published 1994
Report Number EPA/600/J-94/550;
Stock Number PB95-148110
Additional Subjects Glucocorticoid receptors ; Aryl hydrocarbon receptors ; Teratogenic compounds ; Cleft palate ; Hydrocortisone ; Mice ; Hydronephrosis ; Messenger RNA ; Immunohistochemistry ; In situ hybridization ; Northern blotting ; Dose-response relationships ; Down-regulation(Physiology) ; Reprints ; Tetrachlorodibenzodioxins
Library Call Number Additional Info Location Last
NTIS  PB95-148110 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 15p
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widespread environmental contaminant the produces adverse biological effects including carcinogenesis, reproductive toxicity, immune dysfunction, hyperderatosis, hepatotoxicity, thymic involution, and teratogenesis. The present study examines the expression of Ah receptor (AhR) and glucocorticoid receptor (GR) in the embryonic palate following exposure to TCDD, hydrocortison (HC), and HC + TCDD. C57BL/6N pregnant mice were treated with HC (25 or 100 mg/kg/day GD10-13, sc), TCDD (3 microgram/kg/day GD10-13, or 23 microgram/kg GD10, orally), or HC + TCDD (25 mg/kg/day SC and 3 microgram/kg/day orally, GD10-13). Craniofacial tissues were collected from the embryos on GD14 and examined for AhR and GR expression using in situ hybridization, Northern blots, and immunohistochemistry. The authors found that in the embryonic palate exposed to TCDD, the AhR was downregulated and the GR expression increased. Conversely, following HC exposure, the GR was downregulated and AhR levels were elevated. HC + TCDD produced increased expression of both receptors. Effects on AhR appeared to be regulated at the transcriptional level, as both protein and mRNA were altered in similar directions.