1. Application of Biologically Based Lumping To Investigate the Toxicokinetic Interactions of a Complex Gasoline Mixture
- Author
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Micah N. Jasper, Philip J. Bushnell, Sheppard A. Martin, Wendy M. Oshiro, Hisham A. El-Masri, and Jermaine Ford
- Subjects
Simulation error ,Inhalation Exposure ,Physiologically based pharmacokinetic modelling ,Water contaminants ,Chemistry ,General Chemistry ,Chemical interaction ,Complex Mixtures ,Models, Theoretical ,010501 environmental sciences ,01 natural sciences ,Toxicokinetics ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Blood concentration ,Environmental chemistry ,Animals ,Environmental Chemistry ,Female ,Rats, Long-Evans ,Gasoline ,0105 earth and related environmental sciences - Abstract
People are often exposed to complex mixtures of environmental chemicals such as gasoline, tobacco smoke, water contaminants, or food additives. We developed an approach that applies chemical lumping methods to complex mixtures, in this case gasoline, based on biologically relevant parameters used in physiologically based pharmacokinetic (PBPK) modeling. Inhalation exposures were performed with rats to evaluate the performance of our PBPK model and chemical lumping method. There were 109 chemicals identified and quantified in the vapor in the chamber. The time-course toxicokinetic profiles of 10 target chemicals were also determined from blood samples collected during and following the in vivo experiments. A general PBPK model was used to compare the experimental data to the simulated values of blood concentration for 10 target chemicals with various numbers of lumps, iteratively increasing from 0 to 99. Large reductions in simulation error were gained by incorporating enzymatic chemical interactions, in comparison to simulating the individual chemicals separately. The error was further reduced by lumping the 99 nontarget chemicals. The same biologically based lumping approach can be used to simplify any complex mixture with tens, hundreds, or thousands of constituents.
- Published
- 2016