Bioconcentration, metabolism and alterations of thyroid hormones of Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) in Zebrafish

Environ Toxicol Pharmacol. 2015 Sep;40(2):581-6. doi: 10.1016/j.etap.2015.08.020. Epub 2015 Aug 19.

Abstract

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is an organophosphate widely used as a flame retardant, and has frequently been detected in the environment and biota. The present study investigates the bioconcentration and metabolism of TDCPP in fish. Zebrafish embryos (from 2h post-fertilization) were exposed to TDCPP (0, 4, 20 and 100μg/L) for six months. Exposure to TDCPP significantly induced phase I metabolic enzymes 7-ethoxyresorufin O-deethylase (EROD) and 7-methoxyresorufin O-demethylase (MROD) in fish. The mRNA expression of genes related to Phase I and II metabolic enzymes, such as cyp1a1, cyp1b1, cyp1c1 and ugt1ab were also significantly upregulated. Exposure to TDCPP significantly reduced plasma thyroxine (T4) and 3,5,3'-triiodothyronine (T3) levels in females. Chemicals analysis indicated significant levels of TDCPP and its metabolite, bis (1,3-dichloro-2-propyl) phosphate (BDCPP), in the liver. The present study reveals that exposure to low concentrations of TDCPP can cause bioconcentration in fish, and TDCPP can be readily metabolized in liver.

Keywords: Bioconcentration and metabolism; TDCPP; Thyroid hormones; Zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytochrome P-450 Enzyme System / genetics
  • Female
  • Gene Expression Regulation, Enzymologic / drug effects*
  • Liver / drug effects
  • Liver / metabolism
  • Organophosphorus Compounds / analysis*
  • Organophosphorus Compounds / toxicity
  • Thyroid Hormones / blood*
  • Thyroxine / blood
  • Triiodothyronine / blood
  • Zebrafish / embryology*
  • Zebrafish / metabolism
  • Zebrafish Proteins / genetics

Substances

  • Organophosphorus Compounds
  • Thyroid Hormones
  • Zebrafish Proteins
  • Triiodothyronine
  • Cytochrome P-450 Enzyme System
  • tris(1,3-dichloro-2-propyl)phosphate
  • Thyroxine