Toluene diisocyanate (TDI), a highly reactive industrial chemical with widespread use in the manufacture of polyurethane and plastics, is the leading cause of occupational asthma associated with chemical exposure.
We report the effects of TDI vapor (20,100,500,1000 ppb) in vitro on differentiated human bronchial epithelial cells.
Increased mucus was observed by electron microscopy at all TDI concentrations.
Cytotoxicity, as evidenced by cell pyknosis and DNA fragmentation, was detected following a 30-min exposure to TDI concentrations of 100 ppb or higher.
At 1000 ppb, transepithelial resistance was lost.
Using confocal microscopy and double staining, TDI was found colocalized with ciliary tubulin in cultures that had been exposed to 20 and 100 ppb.
These findings are the first to identify TDI binding to human pulmonary epithelial cells and indicate extensive binding to the cilia of differentiated epithelial cells.
The in vivo implications of these findings include decreased ciliary movement and longer retention of TDI and hence increased exposure.
Altered cytoskeletal-derived signal transduction may be a consequence of tubulin involvement.
The effects of such changes on respiratory sensitization remain to be explored.
Mots-clés Pascal : Toxicité, Composé chimique, Isocyanate organique, Composé benzénique, Exposition professionnelle, Médecine travail, Inhalation, Homme, Asthme, Appareil respiratoire pathologie, Bronchopneumopathie obstructive, In vitro, Culture cellulaire, Cellule épithéliale, Alvéolobronchique, Allergie, Immunopathologie, Toluène(diisocyanato)
Mots-clés Pascal anglais : Toxicity, Chemical compound, Organic isocyanate, Benzenic compound, Occupational exposure, Occupational medicine, Inhalation, Human, Asthma, Respiratory disease, Obstructive pulmonary disease, In vitro, Cell culture, Epithelial cell, Bronchioalveolar, Allergy, Immunopathology
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0422984
Code Inist : 002B06C02. Création : 22/03/2000.