The objectives of this research are to achieve better understanding of the effects of environmental and occupational pollutants on mucociliary clearance of the lung and thereby gain insight into the role of ciliary dysfunction in the development of chronic lung disease. The focus of this proposal is the effects of formaldehyde (HCHO) and toluene diisocyanate (TDI) on ciliary function. In vitro studies employing human bronchial ciliated epithelial cells, rabbit tracheal explants and porcine tracheal isolated ciliary axonemes will determine 1) the concentrations and exposure periods of HCHO and TDI necessary for inhibition of ciliary activity, 2) the capability of inhibited ciliated cells to recover function after termination of exposure, 3) the alterations of ciliary axonemal proteins or other cellular components (structural versus regulatory) which correlate with impairment and 4) the existence of a common susceptible site or mechanism of damage to ciliary function by comparison of results between HCHO and TDI. Ciliary activity and its inhibition will be assessed from light microscopic videorecordings by quantitation of changes in beat frequency and zones of active ciliated cells. Cell toxicity will be determined by light microscopic observation. Ultrastructural analysis of treated and control ciliary samples will be made by electron microscopy. Analysis of axonemal and cellular membrane protein alterations will be made by SDS-polyacrylamide gel electrophoresis and two dimensional gel electrophoresis. Changes in ATPase activity will be measured by colorimetric assay. This biochemical and microscopic methodology will provide quantitative measures of HCHO and TDI inhibition and subsequent reversibility, as well as identification of ciliary sites sensitive to HCHO and TDI. Information obtained from this research will elucidate the pathophysiology and mechanisms by which these pollutants produce ciliary dysfunction, and may prove applicable to other airborne pollutants as well. Improved understanding of pollutant-induced susceptibility in mucociliary defense of the lung may yield insight into the contribution of ciliary dysfunction to the pathogenesis of chronic airway disease.
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