The primary objective of this proposal is to characterize mucus-producing epithelial cells isolated from tracheobronchial tissue with emphasis on mucus synthesis and secretion, cell proliferation and related control processes. Work with human and other primate tissue will be stressed. Freshly isolated cells or those in short-term culture will be studied. Cultures will be established using explants or by mass or clonal cultivation of dissociated and fractionated cells. Mucus-producing cells will be identified by histochemical and biochemical methods with confirmation by electron microscopy. Mucus content (quantity and type) and synthesis will be measured histochemically and by pulse labeling with radioactive precursors respectively. DNA, RNA and protein content will be measured by chemical means and synthesis by pulse labeling techniques. The identification and quantitation of cells synthesizing mucins, DNA and other macromolecules will be made by autoradiographic techniques. An examination of cell structure by phase contrast and electron microscopy will be included. Density, size, growth characteristics and karyology will be determined by standard techniques. The effects of a variety of cultural conditions and agents on mucus content and synthesis will be examined. Effects on cell proliferation will also be determined. Variables to be studied will include co-cultivations with feeder layers of mesenchymal cells, use of conditioned medium, addition of growth factors, prostaglandins, hormones or other agents. Another objective of this proposal will be to establish continuously propagable mucus-producing cell lines. Cultural conditions found to promote proliferation and/or function in short-term studies may be employed. Alternatively, functional cells may be transformed by exposure to selected carcinogens and/or viruses.