The physiologically based toxicokinetic (PBTK) model was firstly developed in female rats to quantitatively evaluate toxicokinetics of nonylphenol (NP). Changes in NP serum concentrations over time of single oral NP administration experiments in Sprague-Dawley rats and literature data were collected to establish and calibrate the PBTK model in the SimBiology framework. The calibrated model predicted the serum and tissue NP concentrations of repeat oral NP administration for model evaluation. NP concentrations in serum and tissues (liver, kidneys, adipose, brain, uterus and ovaries) were quantified using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The model output of the time course data (values are within the standard deviation defined for each data point) indicated proximity of predictions to reality. The coefficients of determination r2 were all greater than 0.9, and the root mean squared error (RMSE) were within 0.177-2.027, which means the model predicted and observed serum NP concentrations were in excellent agreement. The results indicated that the model could contribute to a simplification of the future exposure risk assessments of NP in a more realistic scenario and provided a better understanding of the disposition process of NP in human.
Keywords: Nonylphenol; Oral exposure; PBTK; Physiologically based toxicokinetic model; Rats; Risk assessment.
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