ARS | Publication request: Comparing biological effects of estrone (E1) and 17ß-estradiol (E2) in mature fathead minnows

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 2011
Publication Date: N/A

Technical Abstract: The presence of endocrine active compounds such as estrogens in treated wastewater effluent and their effects on aquatic life are causing concern among aquatic resource managers. Among the natural estrogens are 17ß-estradiol, 17a-estradiol, and estrone. Although 17ß-estradiol has received significant study, the biological effects of estrone, one of its breakdown products are less understood, even though the aquatic concentrations of estrone are often higher than those of 17ß-estradiol. We tested two hypotheses in this study: (1) Estrone is less potent than 17ß-estradiol and higher concentration are needed to elicit similar biological effects. (2) High concentrations of each estrogen will increase plasma vitellogenin concentrations in both male and female fathead minnows and result in a decrease in fecundity for female fathead minnows. In two replicate experiments, we exposed mature fathead minnows to three concentrations of each estrogen for 21 days in a flow-through exposure system and measured a broad suite of anatomical (body indices, histopathology), physiological (plasma vitellogenin), behavioral (nest defense), and reproductive endpoints. These endpoints have previously been associated with adverse effects of estrogenic exposures. Although body indices remained unaltered by exposure, secondary sex characteristics exhibited an exposure concentrated-related decline in male fathead minnows. Interestingly, low concentrations of estrone enhanced the aggressiveness of male fathead minnows in a behavioral assay. Vitellogenin concentrations in male fish increased with higher concentrations of both estrogens, but remained unchanged in all female treatments. A decrease in fecundity was observed at high concentrations of 17ß-estradiol as compared with control minnows. These results suggest that estrone is an important contributor to overall estrogenicity in waters receiving treated wastewater effluent. Funding provided by the US EPA GLNPO program (# GL00E57201-0) to HLS.