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Vitellogenin induction by a mixture of steroidal estrogens in freshwater fishes and relevant risk assessment
Author(s) -
Zhang Hui,
Kong FanXiang,
Wang ShiHe,
Yu Yang,
Zhang Min
Publication year - 2009
Publication title -
environmental toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.813
H-Index - 77
eISSN - 1522-7278
pISSN - 1520-4081
DOI - 10.1002/tox.20453
Subject(s) - vitellogenin , ecotoxicology , environmental risk assessment , environmental chemistry , risk assessment , endocrine disruptor , biology , fishery , fish <actinopterygii> , ecology , chemistry , endocrinology , hormone , endocrine system , computer security , computer science
The study method on combined effects of environmental contaminant mixture and ecological risk assessment was discussed. Batch tests were conducted to assess the in vivo potency of binary mixtures of estrogens using plasma vitellogenin concentrations in male crucian carp as the endpoint. The estrogenic potencies of 17β‐estradiol (E 2 ) and 17α‐ethynylestradiol (EE 2 ) were determined following 14 day exposure to the individual chemicals and equipotent binary mixtures. A Nonlinear regression was obtained and 95% confidence limits of effect concentration were achieved using the bootstrap method. Concentration‐response curve for fixed ratio binary mixtures of E 2 and EE 2 was compared with those for individual chemicals, using the biomathematical models of concentration addition (CA) and independent action (IA). A complete overlap was found for the CA predictions with the 95% confidence interval of the best‐fit regression line of the observed responses, and the IA predictions was shown lower than the observations. The observed mixture effects were considerably higher than those of the hormone alone and far exceeded the 95% confidence interval of the estrogen regression lines. The predicted effects of binary mixtures at different mixture ratios indicated that the potential impact of components on mixture would depend predominantly on its concentration, the mixture ratio and its relative potency. Results suggested that E 2 and EE 2 acted together in an additive manner and the combined effects can be accurately predicted in whole range of exposure concentration by the models of CA and IA, the model of CA might be realistic, but more useful for ecological risk assessment. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.