skip to main content
Resource type Show Results with: Show Results with: Index

1,2-Dibromo-4-(1,2-dibromoethyl)-cyclohexane and tris(methylphenyl) phosphate cause significant effects on development, mRNA expression, and circulating bile acid concentrations in chicken embryos

Crump, Doug ; Porter, Emily ; Egloff, Caroline ; Williams, Kim L ; Letcher, Robert J ; Gauthier, Lewis T ; Kennedy, Sean W ; Department of Biology, University of Ottawa, Ottawa, On K1n 6n5

Toxicology and Applied Pharmacology, 15 June 2014, Vol.277(3) [Peer Reviewed Journal]

Full text available online

Citations Cited by
  • Title:
    1,2-Dibromo-4-(1,2-dibromoethyl)-cyclohexane and tris(methylphenyl) phosphate cause significant effects on development, mRNA expression, and circulating bile acid concentrations in chicken embryos
  • Author/Creator: Crump, Doug ; Porter, Emily ; Egloff, Caroline ; Williams, Kim L ; Letcher, Robert J ; Gauthier, Lewis T ; Kennedy, Sean W ; Department of Biology, University of Ottawa, Ottawa, On K1n 6n5
  • Language: English
  • Subjects: 60 Applied LIFE Sciences ; Additives ; Bile Acids ; Chickens ; Concentration Ratio ; Cyclohexane ; Embryos ; Genes ; In Vitro ; Lipids ; Liver ; Liver Cells ; Messenger-RNA ; Metabolism ; Ontogenesis ; Phosphates ; Plant Growth ; Screening ; Thyroid Hormones ; Toxicity ; Pharmacy, Therapeutics, & Pharmacology ; Public Health
  • Is Part Of: Toxicology and Applied Pharmacology, 15 June 2014, Vol.277(3)
  • Description: 1,2-Dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH; formerly abbreviated as TBECH) and tris(methylphenyl) phosphate (TMPP; formerly abbreviated as TCP) are additive flame retardants that are detected in the environment and biota. A recent avian in vitro screening study of 16 flame retardants identified DBE-DBCH and TMPP as important chemicals for follow-up in ovo evaluation based on their effects on cytotoxicity and mRNA expression in avian hepatocytes. In this study, technical mixtures of DBE-DBCH and TMPP were injected into the air cell of chicken embryos at concentrations ranging from 0 to 54,900 ng/g and from 0 to 261,400 ng/g, respectively, to determine effects on pipping success, development, hepatic mRNA expression, thyroid hormone levels, and circulating bile acid concentrations. Both compounds were detectable in embryos at pipping and the β-DBE-DBCH isomer was depleted more rapidly than the α-isomer in tissue samples. DBE-DBCH had limited effects on the endpoints measured, with the exception of the up-regulation of two phase I metabolizing enzymes, CYP3A37 and CYP2H1. TMPP exposure caused embryonic deformities, altered growth, increased liver somatic index (LSI) and plasma bile acid concentrations, and altered mRNA expression levels of genes associated with xenobiotic and lipid metabolism and the thyroid hormone pathway. Overall, TMPP elicited more adverse molecular and phenotypic effects than DBE-DBCH albeit at concentrations several orders of magnitude greater than those detected in the environment. The increase in plasma bile acid concentrations was a useful phenotypic anchor as it was associated with a concomitant increase in LSI, discoloration of the liver tissue, and modulation of hepatic genes involved with xenobiotic and lipid metabolism. - Highlights: • DBE-DBCH and TMPP are not embryolethal to chicken embryos. • TMPP caused deformities, morphometric alterations, and increased plasma bile acids. • DBE-DBCH and TMPP altered mRNA levels of xenobiotic and lipid metabolism genes. • Elevated plasma bile acids suggest that TMPP causes liver dysfunction. • TMPP elicited more adverse molecular and phenotypic effects than DBE-DBCH.
  • Identifier: ISSN: 0041-008X ; E-ISSN: 1096-0333 ; DOI: 10.1016/J.TAAP.2014.03.028