Fish model for assessing the in vivo estrogenic potency of the mycotoxin zearalenone and its metabolites.

Abstract

The in vivo estrogenic potency of zearalenone (ZEA), a mycotoxin produced by different strains of Fusarium fungi, and its metabolites (alpha- and beta-zearalenol), have been studied in fish. Estrogenicity was evaluated using an in vitro competitive receptor binding assay and in vivo induction of vitellogenesis and zonagenesis, two estrogen receptor (ER)-mediated responses that are integral aspects of fish oogenesis. The ER binding affinities of alpha-zearalenol and ZEA in rainbow trout (Oncorhynchus mykiss) were approximately 1/150 and 1/300 to that of estradiol, respectively. Juvenile salmon (Salmo salar) were exposed to a single intraperitoneal injection of ZEA, alpha-zearalenol and beta-zearalenol (each at 1 and 10 mg/kg) and compared to fish injected with estradiol-17 beta (E2; 5 mg/kg) and controls. Using indirect enzyme-linked immunosorbent assay (ELISA) with homologous antibodies, a dose-dependent induction of vitellogenin (Vtg) and eggshell zona radiata proteins (Zr-proteins) were observed 7 days after exposure to ZEA and alpha-zearalenol. beta-Zearalenol did not elevate plasma Vtg levels, but a non-significant elevation of plasma Zr-proteins levels was observed at the highest dose (10 mg/kg). Generally, alpha-zearalenol and ZEA possess estrogenic potencies that are approximately 50% compared to that of E2, and their order of estrogenic potency (in both in vitro receptor competitive binding and in vivo induction of Vtg and Zr-proteins levels) is: alpha-zearalenol > ZEA > beta-zearalenol. Our results show that blood plasma analysis of Vtg and Zr-proteins levels provides a suitable in vivo fish model for assessing the estrogenic potencies of ZEA and its metabolites.

• Authors: A Arukwe, T Grotmol, T B Haugen, F R Knudsen, A Goksøyr
• Journal: The Science of the total environment (Sci Total Environ) Vol. 236 Issue 1-3 Pg. 153-61 (Sep 15 1999) ISSN: 0048-9697 [Print] Netherlands
• PMID: 10535150 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Egg Proteins
• Estrogens, Non-Steroidal
• Receptors, Estrogen
• Vitellogenins
• zearalenol
• Estradiol
• Zearalenone
• Zeranol

Topics

• Animals
• Binding, Competitive
• Egg Proteins (biosynthesis)
• Estradiol (metabolism, pharmacology)
• Estrogens, Non-Steroidal (metabolism, pharmacology)
• Female
• In Vitro Techniques
• Male
• Models, Biological
• Oncorhynchus mykiss
• Oogenesis (drug effects)
• Receptors, Estrogen (drug effects, metabolism)
• Salmo salar
• Vitellogenins (biosynthesis)
• Zearalenone (metabolism, pharmacology)
• Zeranol (analogs & derivatives, pharmacology)