ZFIN ID: ZDB-PUB-170524-3
Quantification of estradiol uptake in zebrafish embryos and larvae
Paige Souder, J., Gorelick, D.A.
Date: 2017
Source: Toxicological sciences : an official journal of the Society of Toxicology   158(2): 465-474 (Journal)
Registered Authors: Gorelick, Daniel
Keywords: embryo, endocrine disruptors, environmental exposure, estrogens
MeSH Terms:
  • Animals
  • Embryo, Nonmammalian/drug effects
  • Embryo, Nonmammalian/metabolism*
  • Endocrine Disruptors/toxicity
  • Estradiol/metabolism*
  • Larva/drug effects
  • Larva/metabolism*
  • Zebrafish/embryology*
  • Zebrafish/growth & development
PubMed: 28535311 Full text @ Toxicol. Sci.
Zebrafish are a powerful model system to assess the molecular and cellular effects of exposure to toxic chemicals during embryonic development. To study the effects of environmental endocrine disruptors, embryos and larvae are commonly exposed to supraphysiologic concentrations of these compounds in the water, but their bioavailability in zebrafish is largely unknown. One hypothesis is that supraphysiologic concentrations of estrogens in the water are required to achieve physiologic levels in vivo, however this has not been directly tested. To test this hypothesis, we developed an assay using radiolabeled estradiol ([3H]E2) to measure uptake from water at multiple concentrations and exposure durations in developing zebrafish from 0-5 days post fertilization (dpf). We found that [3H]E2 uptake increased with increasing concentration, duration, and developmental stage. Percent uptake from the total volume of treatment solution increased with increasing exposure duration and developmental stage, but remained constant with increasing concentration. We also found that the chorion, an acellular envelope surrounding embryos through 3 dpf, did not substantially affect [3H]E2 uptake. Finally, we found that at 1 dpf, estradiol was preferentially taken up by the yolk at multiple exposure durations, while at 2 dpf estradiol was preferentially taken up into the embryonic body. Our results support the hypothesis that exposing zebrafish embryos and larvae to supraphysiologic concentrations of estrogens is required to achieve physiologically-relevant doses in vivo. The isotopic assay reported here will provide a foundation for determining the uptake of other compounds for teratogenicity, toxicology, and drug discovery studies.