This is an original dataset generated at the U.S. EPA. Data was analyzed with the ToxCast Pipeline and deposited for release in invitroDB accessible via the U.S. EPA CompTox Chemicals Dashboard. Dataset is a zip file containing two Excel spreadsheets titled AIME-ERTA_384_Tables_All_Submission_v2 and README_AIME-ERTA_384_Manuscript_Sup_Data_v2. This dataset is associated with the following publication: Hopperstad, K., D. DeGroot, T. Zurlinden, C. Brinkman, R. Thomas, and C. Deisenroth. Chemical Screening in an Estrogen Receptor Transactivation Assay with Metabolic Competence. TOXICOLOGICAL SCIENCES. Society of Toxicology, RESTON, VA, 187(1): 112-126, (2022).

Detection Limit Study. This dataset is associated with the following publication: Reddy, T., R. Flick , J. Lazorchak , M. Smith, B. Wiechman, and D. Lattier. Experimental paradigm for in-lab proxy aquatic studies under conditions of static, non flow through chemical exposures. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 34(12): 2796-2802, (2015).

Detection Limit Study. This dataset is associated with the following publication: Reddy, T., R. Flick , J. Lazorchak , M. Smith, B. Wiechman, and D. Lattier. Experimental paradigm for in-lab proxy aquatic studies under conditions of static, non flow through chemical exposures. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 34(12): 2796-2802, (2015).

Five chemicals [2-ethylhexyl 4-hydroxybenzoate (2-EHHB), 4-nonylphenol-branched (4-NP), 4-tert-octylphenol (4-OP), benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) were subjected to a 21-day Amphibian Metamorphosis Assay (AMA) following OCSPP 890.1100 test guidelines. The selected chemicals exhibited estrogenic or androgenic bioactivity in high throughput screening data obtained from US EPA ToxCast models. Xenopus laevis larvae were exposed nominally to each chemical at 3.6, 10.9, 33.0 and 100 µg/L, except 4-NP for which concentrations were 1.8, 5.5, 16.5 and 50 µg/L. Endpoint data (daily or given study day (SD)) collected included: mortality (daily), developmental stage (SD 7 and 21), hind limb length (HLL) (SD 7 and 21), snout-vent length (SVL) (SD 7 and 21), wet body weight (BW) (SD 7 and 21), and thyroid histopathology (SD 21). 4-OP and BBP caused accelerated development compared to controls at the mean measured concentration of 39.8 and 3.5 µg/L, respectively. Normalized HLL was increased on SD 21 for all chemicals except 4-NP. Histopathology revealed mild thyroid follicular cell hypertrophy at all BBP concentrations, while moderate thyroid follicular cell hypertrophy occurred at the 105 µg /L BBP concentration. Evidence of accelerated metamorphic development was also observed histopathologically in BBP-treated frogs at concentrations as low as 3.5 µg/L. Increased BW relative to control occurred for all chemicals except 4-OP. Increase in SVL was observed in larvae exposed to 4-NP, BBP and DBP on SD 21. With the exception of 4-NP, four of the chemicals tested appeared to alter thyroid axis-driven metamorphosis, albeit through different lines of evidence, with BBP and DBP providing the strongest evidence of effects on the thyroid axis. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

Five chemicals [2-ethylhexyl 4-hydroxybenzoate (2-EHHB), 4-nonylphenol-branched (4-NP), 4-tert-octylphenol (4-OP), benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) were subjected to a 21-day Amphibian Metamorphosis Assay (AMA) following OCSPP 890.1100 test guidelines. The selected chemicals exhibited estrogenic or androgenic bioactivity in high throughput screening data obtained from US EPA ToxCast models. Xenopus laevis larvae were exposed nominally to each chemical at 3.6, 10.9, 33.0 and 100 µg/L, except 4-NP for which concentrations were 1.8, 5.5, 16.5 and 50 µg/L. Endpoint data (daily or given study day (SD)) collected included: mortality (daily), developmental stage (SD 7 and 21), hind limb length (HLL) (SD 7 and 21), snout-vent length (SVL) (SD 7 and 21), wet body weight (BW) (SD 7 and 21), and thyroid histopathology (SD 21). 4-OP and BBP caused accelerated development compared to controls at the mean measured concentration of 39.8 and 3.5 µg/L, respectively. Normalized HLL was increased on SD 21 for all chemicals except 4-NP. Histopathology revealed mild thyroid follicular cell hypertrophy at all BBP concentrations, while moderate thyroid follicular cell hypertrophy occurred at the 105 µg /L BBP concentration. Evidence of accelerated metamorphic development was also observed histopathologically in BBP-treated frogs at concentrations as low as 3.5 µg/L. Increased BW relative to control occurred for all chemicals except 4-OP. Increase in SVL was observed in larvae exposed to 4-NP, BBP and DBP on SD 21. With the exception of 4-NP, four of the chemicals tested appeared to alter thyroid axis-driven metamorphosis, albeit through different lines of evidence, with BBP and DBP providing the strongest evidence of effects on the thyroid axis. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

These data are represented in tables and graphs in the article, "Targeted pathway-based in vivo testing using thyroperoxidase inhibition to evaluate plasma thyroxine as a surrogate metric of metamorphic success in model amphibian Xenopus laevis" by JT Haselman et al. This dataset is associated with the following publication: Haselman, J., J. Olker, P. Kosian, J. Korte, J. Swintek, J. Denny, J. Nichols, J. Tietge, M. Hornung, and S. Degitz. Targeted pathway-based in vivo testing using thyroperoxidase inhibition to evaluate plasma thyroxine as a surrogate metric of metamorphic success in model amphibian Xenopus laevis. TOXICOLOGICAL SCIENCES. Society of Toxicology, RESTON, VA, 175(2): 236-250, (2020).

This research was designed to evaluate whether a biologically-based computational model aligned with an adverse outcome pathway (AOP) could effectively predict animal (in vivo) responses to chemicals shown to inhibit the enzyme aromatase in a non-animal (in vitro) screening assays. Aromatase is an enzyme that plays a critical role in the synthesis of estrogens, an important class of hormones, and chemicals that inhibit aromatase are viewed as probable endocrine disrupting compounds. Although the model was not able to accurately predict the average in vivo responses observed for all chemicals tested, there was strong qualitative to semi-quantitative agreement with the proposed AOP and predictions did fall within the distribution of measured values. Consequently, this “new approach methodology” likely has utility for screening-level assessments. This work helps to establish the confidence and limitations of this approach. The data set includes: 1) High throughput screening results for chemicals identified as aromatase inhibitors. 2) Novel in vitro aromatase inhibition data for six chemicals. 3) Modeled predictions of impacts on 17b-estradiol and vitellogenin concentrations over a range of concentrations. 4) Measured biological effects of 3 aromatase inhibitors in fathead minnows exposed for 24 h. 5) Measured plasma and water concentrations of the test chemicals. This dataset is associated with the following publication: Villeneuve, D., B. Blackwell, J. Cavallin, W. Cheng, R. Conolly, D. Feifarek, K. Jensen, M. Kahl, R. Milsk, S. Poole, E. Randolph, T. Saari, and G. Ankley. Case study in 21st century ecotoxicology: Using in vitro aromatase inhibition data to predict short term in vivo responses in adult female fish. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 40(4): 1155-1170, (2021).

This research was designed to evaluate whether a biologically-based computational model aligned with an adverse outcome pathway (AOP) could effectively predict animal (in vivo) responses to chemicals shown to inhibit the enzyme aromatase in a non-animal (in vitro) screening assays. Aromatase is an enzyme that plays a critical role in the synthesis of estrogens, an important class of hormones, and chemicals that inhibit aromatase are viewed as probable endocrine disrupting compounds. Although the model was not able to accurately predict the average in vivo responses observed for all chemicals tested, there was strong qualitative to semi-quantitative agreement with the proposed AOP and predictions did fall within the distribution of measured values. Consequently, this “new approach methodology” likely has utility for screening-level assessments. This work helps to establish the confidence and limitations of this approach. The data set includes: 1) High throughput screening results for chemicals identified as aromatase inhibitors. 2) Novel in vitro aromatase inhibition data for six chemicals. 3) Modeled predictions of impacts on 17b-estradiol and vitellogenin concentrations over a range of concentrations. 4) Measured biological effects of 3 aromatase inhibitors in fathead minnows exposed for 24 h. 5) Measured plasma and water concentrations of the test chemicals. This dataset is associated with the following publication: Villeneuve, D., B. Blackwell, J. Cavallin, W. Cheng, R. Conolly, D. Feifarek, K. Jensen, M. Kahl, R. Milsk, S. Poole, E. Randolph, T. Saari, and G. Ankley. Case study in 21st century ecotoxicology: Using in vitro aromatase inhibition data to predict short term in vivo responses in adult female fish. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 40(4): 1155-1170, (2021).

Aromatase inhibition is one of the chemical modes of action of concern to EPA's Endocrine Disruptor Screening Program (EDSP). In vitro bioassays that can detect aromatase inhibition are part of both the EDSP tier 1 screening program and are included subset of ToxCast assays employed for EDSP21 screening. An adverse outcome pathway (AOP) linking aromatase inhibition to reproductive dysfunction in fish has been described and endorsed by the OECD, establishing a scientifically sound connection between aromatase inhibition and adverse apical outcomes relevant to risk assessment and regulatory decision-making. Further, computational models that allow for quantitative prediction of dose-response time-course behaviors and the potential severity of the adverse outcome based on in vitro screening data have been developed. The present study provides further weight of evidence to support this AOP and its use in regulatory decision-making. In particular, it identifies rapid responses to aromatase inhibition that can be expected to occur within the first 24 h of exposure, examines the dynamic stability of gene expression responses over that period to help identify appropriate time periods in which characteristic gene expression responses may serve as effective biomarkers of exposure to aromatase inhibitors, and provides insights into different gene regulatory mechanisms that may be operating over the first few hours of exposure versus more systemic endocrine-related regulation that appear to take over after 6-12 h of exposure. These data continue to refine our understanding of this important mode of endocrine disruption and how to more efficiently and effectively both model and test for it to support regulatory decision-making. This dataset is associated with the following publication: Schroeder, A., G. Ankley, T. Habib, N. Garcia-Reyero, B. Escalon, K. Jensen, M. Kahl, E. Durhan, E. Makynen, J. Cavallin, D. Martinovic-Weigelt, E. Perkins, and D. Villeneuve. Rapid effects of the aromatase inhibitor fadrozole on steroid production and gene expression in the ovary of female fathead minnows (Pimephales promelas). GENERAL AND COMPARATIVE ENDOCRINOLOGY. Academic Press Incorporated, Orlando, FL, USA, 252: 79-87, (2017).

Aromatase inhibition is one of the chemical modes of action of concern to EPA's Endocrine Disruptor Screening Program (EDSP). In vitro bioassays that can detect aromatase inhibition are part of both the EDSP tier 1 screening program and are included subset of ToxCast assays employed for EDSP21 screening. An adverse outcome pathway (AOP) linking aromatase inhibition to reproductive dysfunction in fish has been described and endorsed by the OECD, establishing a scientifically sound connection between aromatase inhibition and adverse apical outcomes relevant to risk assessment and regulatory decision-making. Further, computational models that allow for quantitative prediction of dose-response time-course behaviors and the potential severity of the adverse outcome based on in vitro screening data have been developed. The present study provides further weight of evidence to support this AOP and its use in regulatory decision-making. In particular, it identifies rapid responses to aromatase inhibition that can be expected to occur within the first 24 h of exposure, examines the dynamic stability of gene expression responses over that period to help identify appropriate time periods in which characteristic gene expression responses may serve as effective biomarkers of exposure to aromatase inhibitors, and provides insights into different gene regulatory mechanisms that may be operating over the first few hours of exposure versus more systemic endocrine-related regulation that appear to take over after 6-12 h of exposure. These data continue to refine our understanding of this important mode of endocrine disruption and how to more efficiently and effectively both model and test for it to support regulatory decision-making. This dataset is associated with the following publication: Schroeder, A., G. Ankley, T. Habib, N. Garcia-Reyero, B. Escalon, K. Jensen, M. Kahl, E. Durhan, E. Makynen, J. Cavallin, D. Martinovic-Weigelt, E. Perkins, and D. Villeneuve. Rapid effects of the aromatase inhibitor fadrozole on steroid production and gene expression in the ovary of female fathead minnows (Pimephales promelas). GENERAL AND COMPARATIVE ENDOCRINOLOGY. Academic Press Incorporated, Orlando, FL, USA, 252: 79-87, (2017).