Simultaneous quantification of T4, T3, rT3, 3,5-T2 and 3,3'-T2 in larval zebrafish (Danio rerio) as a model to study exposure to polychlorinated biphenyls

Biomed Chromatogr. 2018 Jun;32(6):e4185. doi: 10.1002/bmc.4185. Epub 2018 Jan 29.

Abstract

Environmental toxicants that interfere with thyroid hormone (TH) signaling can impact growth and development in animals and humans. Zebrafish represent a model to study chemically induced TH disruption, prompting the need for sensitive detection of THs. Simultaneous quantification of 3,3',5-triiodo-l-thyronine (T3), thyroxine (T4), 3,3',5'-triiodo-l-thyronine (rT3), 3,5-diiodo-l-thyronine (3,5-T2) and 3,3'-diiodo-l-thyronine (3,3'-T2) in zebrafish larvae was achieved by ultra-performance liquid chromatography-tandem mass spectrometry in positive ion mode. Solid-phase extraction with SampliQ cartridges and derivatization with 3 m hydrochloric acid in n-butanol reduced matrix effects. Derivatized compounds were separated on an Acquity UPLC BEH C18 column with mobile phases consisting of 0.1% acetic acid in deionized water and 0.1% acetic acid in methanol. The limits of detection ranged from 0.5 to 0.6 pg injected on column. The method was validated by evaluating recovery (77.1-117.2%), accuracy (87.3-123.9%) and precision (0.5-12.4%) using diluted homogenized zebrafish embryos spiked with all target compounds. This method was then applied to zebrafish larvae collected after 114 h of exposure to polychlorinated biphenyls (PCBs), including PCB 28, PCB 66 and PCB 95, or the technical mixture Aroclor 1254. Exposure to PCB 28 and PCB 95 increased the T4:T3 ratio and decreased the T3:rT3 ratio, demonstrating that this method can effectively detect PCB-induced alterations in THs.

Keywords: PCBs; UPLC-MS/MS; derivatization; thyroid hormones; zebrafish.

MeSH terms

  • Animals
  • Chromatography, High Pressure Liquid
  • Disease Models, Animal
  • Endocrine Disruptors / toxicity
  • Larva / drug effects*
  • Larva / metabolism
  • Limit of Detection
  • Linear Models
  • Polychlorinated Biphenyls / toxicity*
  • Reproducibility of Results
  • Tandem Mass Spectrometry
  • Thyroid Hormones / analysis*
  • Zebrafish

Substances

  • Endocrine Disruptors
  • Thyroid Hormones
  • Polychlorinated Biphenyls