Disposition and Clearance of Tungsten after Single-dose Oral and Intravenous Exposure in Rodents

Abstract

Tungsten (W) has been nominated for study to the National Toxicology Program (NTP) because of reported associations between concentrations of W in drinking water and childhood leukemia. The disposition of W (administered as sodium tungstate dihydrate in water) in plasma, liver, kidneys, uterus, femur, and intestine of rodents (Sprague-Dawley rats and C57BL/6N mice) was characterized after exposures by oral gavage (1, 10, or 100 mg/kg) or intravenous (1 mg/kg) administration. Each tissue (or plasma) was collected and analyzed by inductively coupled plasma mass spectrometry at 1, 2, 4, or 24 h after dose administration. W was observed in plasma and all tissues after both gavage and iv administration. In rats, concentrations in plasma and most tissues peaked at 4 h. In mice, concentrations in plasma and most tissues peaked at 1 h. Although the amount of W in each matrix decreased significantly by 24 h, there was W remaining in several tissues, especially at the higher doses.

This work was supported by contract N01-ES-25483 from the National Institute of Environmental Health Sciences (NIEHS). We thank Dr. L. T. Burka at NIEHS for his critical review of the article.