Reduction of vitellogenin synthesis by an aryl hydrocarbon receptor agonist in the white sturgeon (Acipenser Transmontamus)

• Published in: Environmental toxicology and chemistry Vol. 28; no. 8; pp. 1749 - 1755
• Main Authors: Palumbo, Amanda J., Denison, Michael S., Doroshov, Serge I., Tjeerdema, Ronald S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Periodicals, Inc 01.08.2009; Blackwell Publishing Ltd
• Subjects: Acipenser; Acipenser transmontanus; agonists; Animals; Antiestrogen; Aryl hydrocarbon receptor; biosynthesis; Contaminants; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP1A1 - metabolism; Dioxins; Down-Regulation; Endocrine disruption; endocrine-disrupting chemicals; Environmental conditions; Environmental effects; enzyme inhibition; Estradiol; Estradiol - pharmacology; Estrogens; Fish; Fishes; Fishes - metabolism; hormone agonists; Hydrocarbons; Industrial wastewater; metabolism; Microsomes, Liver; Microsomes, Liver - metabolism; Municipal wastewater; PCB; pharmacology; Phenols; Phenols - pharmacology; Polychlorinated biphenyls; Polycyclic aromatic hydrocarbons; receptors; Receptors, Aryl Hydrocarbon; Receptors, Aryl Hydrocarbon - agonists; Regulatory agencies; reproductive toxicology; Sewage treatment plants; Studies; Sturgeon; vitellogenesis; Vitellogenin; Vitellogenins; Vitellogenins - biosynthesis
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1897/08-481.1

Migrating white sturgeon (Acipenser transmontamus) may be subject to agricultural, municipal, and industrial wastewater effluents that likely contain different classes of endocrine‐disrupting contaminants. Concern is mounting about the negative effects of environmental estrogens on fish reproduction; however, in environmental mixtures, the affects from estrogenic compounds may be suppressed by aryl hydrocarbon receptor (AhR) ligands. Indeed, reductions in 17p‐estradiol‐induced (0.01 and 1 mg/kg) vitellogenin (VTG) levels were observed in white sturgeon coinjected with β‐naphthoflavone (BNF; 50 mg/kg), a model for contaminants that activate the AhR. Variation in the time of injection was used to attempt to correlate VTG inhibition to ethoxy‐resorufin‐O‐deethylase activity. No evidence was found to suggest that the inhibition of VTG is a direct result of enhanced estrogen metabolism by BNF‐induced enzymes. Results of the present study are relevant for monitoring programs that measure VTG, because these results show that AhR‐active environmental contaminants can repress VTG synthesis, which commonly is used as an indicator of estrogen‐mimicking contaminants. Furthermore, suppression of natural estrogen signaling by AhR agonists may have significant effects on fish reproduction.