Time course of effects of tetraethoxysilane (TEOS) on the kidney and blood silicon concentration in mice.

To clarify the time course of toxicological effects of tetraethoxysaline [Si(OC2H5)4, TEOS] on the kidney and the relationship between blood silicon levels (Si-B) and the effects, 250 mg/kg or 500 mg/kg TEOS was intraperitoneally administered to ten 5-week-old male ICR mice (SPF grade) in each group, and morphological and functional changes of the kidney were assessed at 12 h, 24 h, 3 days and 2 weeks after administration of TEOS. Injury to tubular epithelial cells was observed in mice killed 12 and 24 h after administration, and its severity increased with increasing dosage. The mean values of blood urea nitrogen exhibited dose-related increase in mice sacrificed 24 h after the administration. The concentrations of Si-B increased in order of the administered doses of TEOS, and then decreased steadily. The results of Si-B were consistent with the concept that renal toxicity of TEOS is mediated by siliceous compounds. The kidney was recovering from injury 3 days after administration, and had developed tubulointerstitial nephritis, which could be regarded as repaired lesion of acute injury, by 2 weeks after administration.