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Notice This document has been reviewed in accordance with U.S. Environmental Protection Agency Policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. ii Foreword This document is one in a series of guidance documents intended to aid dischargers and their consultants in(More)
Many chemicals that adversely affect reproduction and/or development do so through multiple pathways within the reproductive tract and hypothalamic-pituitary-gonadal axis. Notable in this regard are fungicides, such as prochloraz or fenarimol, which in mammals have the potential to impact endocrine function through inhibition of CYP enzymes involved in(More)
Little is known concerning the potential ecological effects of hormonally active substances associated with discharges from animal feeding operations. Trenbolone acetate is a synthetic anabolic steroid that is widely used in the United States to promote growth of beef cattle. Metabolites of trenbolone acetate include the stereoisomers 17alpha- and(More)
Graphical systems models are powerful tools that can help facilitate hypothesis-driven ecotoxicogenomic research and aid in mechanistic interpretation of results. This paper describes a novel graphical model of the teleost brain-pituitary-gonadal (BPG) axis designed for ecotoxicogenomics research on endocrine-disrupting chemicals using small fish models.(More)
1H NMR spectroscopy was used to profile metabolite changes in the livers of fathead minnows (Pimephales promelas) exposed to the synthetic estrogen 17alpha-ethynylestradiol (EE2) via a continuous flow water exposure. Fish were exposed to either 10 or 100 ng EE2/L for 8 days, followed by an 8 day depuration phase. Livers were collected after days 1, 4, and 8(More)
Effects of bisphenol A (BPA) on ovarian transcript profiles as well as targeted end points with endocrine/reproductive relevance were examined in two fish species, fathead minnow (Pimephales promelas) and zebrafish (Danio rerio), exposed in parallel using matched experimental designs. Four days of waterborne exposure to 10 μg BPA/L caused significant(More)
BACKGROUND Several chemicals in the environment have the potential to inhibit aromatase, an enzyme critical to estrogen synthesis. OBJECTIVES The objective of this study was to provide a detailed characterization of molecular and biochemical responses of female fathead minnows to a model aromatase inhibitor, fadrozole (FAD). METHODS Fish were exposed(More)
Methoprene is an insect juvenile growth hormone mimic, which inhibits pupation and is used for the control of emergent insect pests such as mosquitoes. Researchers have hypothesized that methoprene use in US may be a contributing factor to the recent increase in malformed amphibians. However, little is known concerning the developmental toxicity of(More)
Widespread environmental contamination by bisphenol A (BPA) has created the need to fully define its potential toxic mechanisms of action (MOA) to properly assess human health and ecological risks from exposure. Although long recognized as an estrogen receptor (ER) agonist, some data suggest that BPA may also behave as an androgen receptor (AR) antagonist.(More)
A challenge in the field of ecotoxicology is the linkage of alterations at molecular and biochemical levels of organization to adverse outcomes in individuals and populations. In the present study, a predictive relationship between plasma vitellogenin (VTG) concentration and fecundity in female fathead minnows (Pimephales promelas) was derived from 21-d(More)