Stability studies of alkoxysilanes in aqueous media.

In order to correlate hydrolysis rates under physiological conditions to differences in toxicity of trimethoxysilane, tetramethoxysilane, and methyltrimethoxysilane, the rates of hydrolysis of these compounds were studied in deionized water, sodium phosphate buffer solution at pH 7.4, and 10% rat serum in sodium phosphate buffer at 37.4 degrees C.

Subchronic inhalation toxicity of tetramethoxysilane in rats.

Sprague-Dawley rats were exposed 6 hr/day, 5 days a week, for 28 days to tetramethoxysilane (TMOS) at concentrations of 0, 1, 5, and 10 ppm (Phase I study) and to 0, 15, 30, and 45 ppm (Phase II study). All of the rats exposed to 45 ppm TMOS died or were sacrificed in a moribund state during the 28-day study period. Statistically significant changes were observed in food consumption, body weights, and clinical chemistry parameters in the animals exposed to 30 ppm TMOS.

A novel mutation selectively decreases complex I and cytochrome c oxidase subunits in Chinese hamster mitochondria.

Chinese hamster subunits of mitochondrial respiratory Complex I (NADH-ubiquinone reductase), Complex IV (cytochrome c oxidase), and Complex V (oligomycin-sensitive ATPase) were identified by immunoprecipitation and/or Western immunoblotting with antibody to the corresponding beef heart complexes. In the Chinese hamster lung cell mutant Gal 32, cytochrome c oxidase activity and its mitochondrially synthesized subunits (I, II, and III) are substantially decreased, but a cytoplasmically synthesized subunit (IV) is present at wild type levels. Complex I activity and five of its subunits are greatly diminished in Gal 32; several of the affected Complex I subunits correspond in mobility to mitochondrial translation products.