Effect of chromates on ciliated cells of rat tracheal epithelium.

Exposure to chromates is an occupational hazard that may result in disease of the respiratory tract. Specific subcellular effects of exposure to this chemical that might be the basis for observed pathologic findings were assessed in tracheal organ culture and excised whole tracheas. Chromate concentrations of 10 mg/ml or more were found to induce ciliostasis within 20 minutes and to kill cells within 24 hours. Levels between 10mug/ml and 100 mug/ml were not ciliostatic but resulted in cytotoxicity after a delay of several hours. Ultrastructural alterations associated with chromate-induced cytotoxicity are similar to the progressive degenerative changes that result from other chemical injuries. An inhibitory effect of chromate on protein synthesis, RNA synthesis, or succinic dehydrogenase activity could not be demonstrated. The data suggest that damage to the plasmalemma by chromates may be responsible for the observed change.