Rat tracheal explants were incubated in tissue culture medium containing various concentrations of Na2CrO4. There was a dose-related inhibition of mucus glycoprotein secretion by the explants at all concentrations of Na2CrO4 evaluated between 0.03 mM and 2.16 mM. Plots of amount of glycoprotein secreted versus log of chromate concentration suggested that there were two types of inhibition occurring, one of which was only observed at higher concentrations of Na2CrO4 in the medium (≥0.5 mM). At concentrations of 0.5 mM and above, we also observed inhibition of precursor (D-[3H]glucosamine) uptake and concurrent morphologic damage in the epithelium of the tracheal slices. The histopathology findings included damage to ciliated cells, severe epithelial desquamation, and severe epithelial cell nuclear pyknosis. The authors conclude from these experiments (1) that we can confirm the work of others that incubation of tracheal slices in vitro in medium containing chromate ion causes morphologically observable damage to the epithelial cells, especially the ciliated cells, (2) that concentrations of chromate sufficient to elicit morphologic damage also inhibit uptake of low molecular weight precursors of mucus glycoproteins into tracheal slices and also inhibit secretion of glycoproteins by such slices, (3) that we can detect a hitherto unrecognized mode of action of chromate ion, i.e., inhibition of glycoprotein secretion at concentrations that do not elicit morphologic damage, and (4) that determination of glycoprotein secretion by tracheal explants offers a sensitive, quantitative technique for studying the effects of soluble air and water pollutants on airway metabolism.
|Original language||English (US)|
|Number of pages||4|
|State||Published - 1977|
ASJC Scopus subject areas
- Pathology and Forensic Medicine