Kinetics of germanium dioxide in rats

The kinetics of germanium dioxide (GeO₂) in single dose and repeated exposures were investigated in male Wistar rats. In the single dose GeO₂ (100 mg/kg BW, p.o.) exposure study, values of several kinetic parameters were shown as follows, a maximum concentration in serum of 15.5±0.7 μg/ml (mean±S.E.M.), an absorption half-life of 0.7±0.1 h (mean±S.E.M.), an elimination half-life of 2.3±0.5 h (mean±S.E.M.), a distribution of the central compartment V(p) (3.1±0.3 l, mean±S.E.M.), and the apparent volume of distribution of the tissue compartment V(t) (8.5±2.9 l, mean±S.E.M.). In the repeated exposure study, 730±92 mg GeO₂ in 1 l double-distilled H₂O (=100 mg/kg/day) was given daily to rats for 4 weeks (p.o.). After sacrificing the rats, the analysis of tissue distribution showed that GeO₂ was accumulated in some important organs or tissues in the body, especially the peripheral nerves and kidney. These results indicate that GeO₂ could be absorbed rapidly but had a longer elimination half-life in rats. In addition, GeO₂ was accumulated especially in the nerves and kidney following long-term exposure. Copyright (C) 1999 Elsevier Science Ireland Ltd.