| Title: | Human plasma and liver concentrations of styrene estimated by combining a simple physiologically based pharmacokinetic model with rodent data |
| Author(s): | Miura T; Uehara S; Nakazato M; Kusama T; Toda A; Kamiya Y; Murayama N; Shimizu M; Suemizu H; Yamazaki H; |
| Address: | "Showa Pharmaceutical University. Central Institute for Experimental Animals. Shin Nippon Biomedical Laboratories, Ltd" |
| ISSN/ISBN: | 1880-3989 (Electronic) 0388-1350 (Linking) |
| Abstract: | "Long-term exposure to certain volatile organic compounds is a significant public health concern. A variety of food containers and drinking cups prepared from polystyrene or polystyrene-related plastics could contain styrene monomer. In the current study, the concentrations of styrene in plasma and liver were surveyed and determined after oral doses of 25 mg/kg to rats and 200 mg/kg to control and humanized-liver mice. Plasma concentrations of styrene in rats were still detected 2 hr after 10-25 mg/kg oral doses. In contrast, after an order of magnitude higher oral dose of styrene (200 mg/kg) to mice, styrene in mouse plasma was rapidly cleared within 15 min to the limit-of-detection level. However, unmetabolized styrene was detected in mouse liver 24 hr after oral treatment. A simple physiologically based pharmacokinetic (PBPK) model capable of estimating blood and liver concentrations of styrene was established for rats. A human PBPK model was then set up for styrene by using the same intrinsic hepatic clearances in rats and humans and by applying allometric scaling to rat parameters obtained from the plasma concentrations of styrene in rats. By reverse dosimetry analysis (from concentrations to doses), we found that the 95th percentile values of styrene concentrations (0.132 ng/mL) reported in United States biomonitoring data of more than 1000 human blood samples may imply exposure to repeated oral doses of styrene of 2.89 microg/kg/day. These results suggest that styrene biomonitoring data in human blood samples imply exposures roughly similar to or lower than the established tolerable daily intake level of 7.7 mug/kg/day" |
| Keywords: | "Administration, Oral Animals Food Packaging Liver/*metabolism Male Metabolic Clearance Rate Mice, Inbred ICR Mice, Transgenic Models, Animal Models, Biological No-Observed-Adverse-Effect Level Rats, Sprague-Dawley Styrene/administration & dosage/*blood/*p;" |
| Notes: | "MedlineMiura, Tomonori Uehara, Shotaro Nakazato, Mayuko Kusama, Takashi Toda, Akiko Kamiya, Yusuke Murayama, Norie Shimizu, Makiko Suemizu, Hiroshi Yamazaki, Hiroshi eng Japan 2019/08/06 J Toxicol Sci. 2019; 44(8):543-548. doi: 10.2131/jts.44.543" |
