Tissue distribution and urinary excretion of inorganic arsenic and its methylated metabolites in C57BL6 mice following subchronic exposure to arsenate in drinking water
- Pharmacokinetics Branch, Experimental Toxicology Division, Mail Stop B143-01, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)
- Battelle Marine Sciences Laboratory, Sequim, WA (United States)
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States)
- University of New Mexico, Albuquerque, NM 87131 (United States)
The relationship of exposure and tissue concentration of parent chemical and metabolites over prolonged exposure is a critical issue for chronic toxicities mediated by metabolite(s) rather than parent chemical alone. This is an issue for As{sup V} because its trivalent metabolites have unique toxicities and relatively greater potency compared to their pentavalent counterparts for many endpoints. In this study, dose-dependency in tissue distribution and urinary excretion for inorganic arsenic and its methylated metabolites was assessed in female C57Bl/6 mice exposed to 0, 0.5, 2, 10 or 50 ppm arsenic (as arsenate, As{sup V}) in their drinking water for 12 weeks. No adverse effects were observed and body weight gain did not differ significantly among groups. Urinary excretion of arsenite monomethylarsonous acid (MMA{sup III}), dimethylarsinous acid (DMA{sup III}), dimethylarsinic acid (DMA{sup V}), and trimethylarsine oxide (TMAO) increased linearly with dose, whereas As{sup V} and monomethylarsonic acid (MMA{sup V}) excretion was non-linear with respect to dose. Total tissue arsenic accumulation was greatest in kidney > lung > urinary bladder >>> skin > blood > liver. Monomethyl arsenic (MMA, i.e. MMA{sup III} + MMA{sup V}) was the predominant metabolite in kidney, whereas dimethylarsenic (DMA, i.e., DMA{sup III} + DMA{sup V}) was the predominant metabolite in lung. Urinary bladder tissue had roughly equivalent levels of inorganic arsenic and dimethylarsenic, as did skin. These data indicate that pharmacokinetic models for arsenic metabolism and disposition need to include mechanisms for organ-specific accumulation of some arsenicals and that urinary metabolite profiles are not necessarily reflective of target tissue dosimetry.
- OSTI ID:
- 21180455
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 232, Issue 3; Other Information: DOI: 10.1016/j.taap.2008.07.018; PII: S0041-008X(08)00317-7; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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