Data from: Differential sensitivity to in vitro inhibition of cytochrome P450 aromatase (CYP19) activity among 18 freshwater fishes

There is significant concern regarding potential impairment of fish
reproduction associated with endocrine disrupting chemicals. Aromatase
(CYP19) is a steroidogenic enzyme involved in the conversion of androgens
to estrogens. Inhibition of aromatase by chemicals can result in reduced
concentrations of estrogens leading to adverse reproductive effects. These
effects have been extensively investigated in a small number of laboratory
model fishes, such as fathead minnow (Pimephales promelas), Japanese
medaka (Oryzias latipes), and zebrafish (Danio rerio). But, differences in
sensitivity among species is largely unknown. Therefore, this study took a
first step towards understanding potential differences in sensitivity to
aromatase inhibitors among fishes. Specifically, a standard in vitro
aromatase inhibition assay using subcellular fractions of whole tissue
homogenates was used to evaluate the potential sensitivity of eighteen
phylogenetically diverse species of freshwater fish to the nonsteroidal
aromatase inhibitor fadrozole. Sensitivity to fadrozole ranged by more
than 52-fold among these species. Five species were further investigated
for sensitivity to up to four additional nonsteroidal aromatase
inhibitors, letrozole, imazalil, prochloraz, and propiconazole. Potencies
of each of these chemicals relative to fadrozole ranged by up to two
orders of magnitude among the five species. Fathead minnow, Japanese
medaka, and zebrafish were among the least sensitive to all the
investigated chemicals; therefore, ecological risks of aromatase
inhibitors derived from these species might not be adequately protective
of more sensitive native fishes. This information could guide more
objective ecological risk assessments of native fishes to chemicals that
inhibit aromatase.