Investigations in this research grant are directed towards a better understanding of the products of pulmonary secretions and the events which regulate the biosynthesis of the mucus glycoproteins of pig tracheal secretions. Normal bronchial mucins are not secreted in abundance and the difficulty in obtaining control human materials prompted us to focus on the pig pulmonary tract mucins. The pig is considered a useful model for studies which could be extrapolated to the human situation. Objectives include isolation and characterization of glycoproteins from pig trachea, including developing new techniques for structural characterization, culturing biopsies obtained from the pig pulmonary tract by fiberoptic bronchoscopy in the presence of labeled precursors such as (3H)glucosamine, (3H)fucose and (35S)sulfate. Biochemical studies will be complemented by histology and electron microscopy.