This paper describes the results of an international ring trial (round robin study) of in vitro methods used to measure chemical biotransformation in fish. Researchers at six laboratories in the U.S. and Europe evaluated six test chemicals (cyclohexyl salicylate, fenthion, 4-n-nonylphenol, deltamethrin, methoxychlor, and pyrene) using two in vitro systems (liver S9 fraction and isolated hepatocytes) derived from rainbow trout livers. This information was then evaluated to quantitatively characterize assay reliability (repeatability and reproducibility) and evaluate potential user bias associated with the methods. Additional calculations were performed using established models to estimate in vivo levels of hepatic clearance and predict the effects on chemical biotransformation on chemical bioaccumulation. The Science Hub dataset includes all information presented in the paper as figures and tables including, as appropriate, individual values used to calculate reported means and standard deviations. Also included are all datasets provided as Supplementary Data. This dataset is associated with the following publication: Nichols, J., K. Fay, M.J. Bernhard, I. Bischof, J. Davis, M. Halder, J. Hu, K. Johanning, H. Laue, D. Nabb, C. Schlechtriem, H. Segner, J. Swintek, J. Weeks, and M. Embry. Reliability of In Vitro methods used to measure intrinsic clearance of hydrophobic organic chemicals by rainbow trout: Results of an international ring trial. TOXICOLOGICAL SCIENCES. Society of Toxicology, RESTON, VA, 164(2): 563-575, (2018).

This dataset provides measured in vitro intrinsic clearance rates for 54 chemicals tested using isolated hepatocytes from humans, rats, and rainbow trout. The test chemicals were selected to provide broad coverage across the industrial and pesticidal chemical space while also prioritizing chemicals of interest to EPA’s Endocrine Disruptor Screening Program (EDSP). A data evaluation framework was developed to identify results suitable for rate reporting. Acceptable results were then used to evaluate the chemical domain of applicability of the applied methods, the influence of starting substrate concentration on measured rates of intrinsic clearance, and differences in metabolic activity among species. These findings provide data for chemicals of specific interest to the EDSP. More importantly, the results provide critical guidance on future use of in vitro biotransformation assays to support high-throughput chemical risks assessments. This dataset is associated with the following publication: Black, S., J. Nichols, K. Fay, S. Matten, and S. Lynn. Evaluation and comparison of in vitro intrinsic hepatic clearance rates measured using cryopreserved hepatocytes from humans, rats, and rainbow trout. TOXICOLOGY. Elsevier Science Ltd, New York, NY, USA, 457: 152819, (2021).

This ScienceHub dataset provides characterization data for a pooled sample of trout liver S9 fractions that was used to study the in vitro intrinsic clearance of selected cationic surfactants. These data describe the activity of the pooled sample toward prototypical substrates for cytochrome P450 (CYP) 1A, glutathione-S-transferase, and UDP-glucuronosyltranserase. Also provided are the protein content and total CYP content of the sample and well as information pertaining to the size and gender of fish from which the original sample was obtained. This dataset is associated with the following publication: Droge, S., J. Armitage, J. Arnot, P. Fitzsimmons, and J. Nichols. Biotransformation Potential of Cationic Surfactants in Fish Assessed with Rainbow Trout Liver S9 Fractions. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 40(11): 3123-3136, (2021).

Sediment was dosed with six highly hydrophobic chemicals with estimated log Kows ranging up to 18.3. Sediment bioaccumulation tests with Lumbriculus variegatus were performed with the dosed sediment. The attached dataset contains the concentrations in the organisms from the uptake and elimination portions of the test. and supporting data, e.g. lipid contents and weight change for the organisms. This dataset is associated with the following publication: Burkhard, L., T. Lahren, T. Highland, R. Hockett, D. Mount, and T. Norberg-King. Bioaccumulation of highly hydrophobic chemicals by Lumbriculus variegatus. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY. Springer, New York, NY, USA, 76(1): 129-141, (2019).

The purpose of this study was to compare two in vitro systems, cryopreserved trout hepatocytes and trout liver S9 fractions, used to predict in vivo levels of biotransformation in fish. This information is needed to refine modeled estimates of bioaccumulation for hydrophobic organic chemicals that undergo biotransformation. In this effort we used trout hepatocytes to measure in vitro biotransformation of 6 polycyclic aromatic hydrocarbons (PAHs). The results were compared to metabolism rates reported previously for trout liver S9 fractions. Results obtained using both in vitro systems were then used to predict measured levels of hepatic clearance for the same test chemicals exhibited by isolated perfused livers. The results of this study suggest that both in vitro systems are well suited for performing in vitro-in vivo metabolism extrapolations with fish as a means for improving modeled bioaccumulation predictions. This dataset is associated with the following publication: Fay, K., P. Fitzsimmons, A. Hoffman, and J. Nichols. Comparison of trout hepatocytes and liver S9 fractions as in vitro models for predicting hepatic clearance in fish. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, FL, USA, 36(2): 463-471, (2017).

The dataset, which is presented as an Excel spreadsheet, contains all data which is presented as figures in Nichols et al., Measurement of kinetic parameters for biotransformation of polycyclic aromatic hydrocarbons by trout liver S9 fractions: Implications for bioaccumulation assessment, accepted for publication in Applied In Vitro Toxicology 04/2017. Additional information if provided regarding reaction conditions used to characterize liver S9 fractions and perform PAH depletions studies. This dataset is associated with the following publication: Nichols, J., M. Ladd, and P. Fitzsimmons. Measurement of kinetic parameters for biotransformation of polycyclic aromatic hydrocarbons by trout liver S9 fractions: Implications for bioaccumulation assessment. Applied In Vitro Toxicology. Mary Ann Liebert, Inc., Larchmont, NY, USA, 4(4): 365-378, (2018).

This dataset, presented as an Excel spreadsheet, contains all data presented as figures and tables in an article by Nichols et al, entitled "In vitro-in vivo extrapolation of hepatic biotransformation data for fish. III. An in-depth case study with pyrene" and published in Environmental Toxicology and Chemistry, 2023. The dataset describes results from a paired set of experiments designed to evaluate the accuracy of in vitro to in vivo metabolism extrapolation procedures for fish. Results showed that measured rates of in vitro intrinsic clearance, when extrapolated to the whole liver, underestimated apparent rates of in vivo activity by about a factor of 4 (assuming the liver is the only site of biotransformation). These findings may have important implications for the use of IVIVE methods in bioaccumulation assessments for fish. This dataset is associated with the following publication: Nichols, J., P. Fitzsimmons, A. Hoffman, and K. Wong. In vitro-in vivo extrapolation of hepatic biotransformation data for fish. III. An in-depth case study with pyrene. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 42(7): 1501-1515, (2023).

The National Contaminant Biomonitoring Program (NCBP), which was developed and maintained by the U.S. Fish and Wildlife Service (FWS), monitored concentrations of environmental contaminants in freshwater fish over a period of about 20 years. Beginning in the 1960s as a component of the multi-agency National Pesticide Monitoring Program (NPMP) and continuing through the mid-1980s, freshwater fish were periodically collected from a national network of stations for analysis of pesticides, PCBs, and other contaminants. The NPMP/NCBP database of contaminant concentrations is the most extensive of its kind, unique in its breadth and depth with respect to environmental contaminant concentrations in fish. The data and information from the NCBP are sought often by a national and international clientele; especially frequent users are biologists in FWS field offices and USGS Water Science Centers. The fish network was suspended by FWS in 1986 pending development of the Biomonitoring of Environmental Status and Trends (BEST) program. The BEST program and the NPMP/NCBP database were transferred to the National Biological Survey/Service (NBS) in 1993. At that time ongoing studies by NBS Inventory and Monitoring (I and M) and the USGS National Water Quality Assessment Program (NAWQA) generated new data at NCBP sites. The database was subsequently (1996) transferred to USGS. The database derived from the NCBP is unique in its ability to characterize the exposure of free-ranging organisms, including threatened and endangered species, to toxic contaminants.

This dataset describes the results of a set of experiments, the goal of which was to evaluate the effects of protease inhibitors on the trout liver S9 substrate depletion assay. The presented data show that addition of phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, substantially increases the working lifetime of the trout S9 assay, resulting in improved detection of low intrinsic clearance rates. These findings substantially increase the utility of the trout S9 assay and may have broad implications for its use to support chemical bioaccumulation assessments. This dataset is associated with the following publication: Nichols, J., A. Hoffman, J. Swintek, S. Droge, and P. Fitzsimmons. Addition of phenylmethylsulfonyl fluoride (PMSF) substantially increases the working lifetime of the trout liver S9 substrate depletion assay resulting in improved detection of low intrinsic clearance rates. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 40(1): 148-161, (2021).

This dataset describes the results of a set of experiments, the goal of which was to evaluate the effects of protease inhibitors on the trout liver S9 substrate depletion assay. The presented data show that addition of phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, substantially increases the working lifetime of the trout S9 assay, resulting in improved detection of low intrinsic clearance rates. These findings substantially increase the utility of the trout S9 assay and may have broad implications for its use to support chemical bioaccumulation assessments. This dataset is associated with the following publication: Nichols, J., A. Hoffman, J. Swintek, S. Droge, and P. Fitzsimmons. Addition of phenylmethylsulfonyl fluoride (PMSF) substantially increases the working lifetime of the trout liver S9 substrate depletion assay resulting in improved detection of low intrinsic clearance rates. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 40(1): 148-161, (2021).