title: Biosynthesis of respiratory-tract mucins. Incorporation of radioactive precursors into glycoproteins by canine tracheal explants in vitro.
abstract: 1. Canine tracheal explants, cultured in medium 199, actively incorporated radioactive precursors into secreted macromolecules in vitro. 2. Puromycin, 6-diazo-5-oxo-l-norleucine and ouabain markedly inhibited the incorporation of these precursors. 3. Exogenous glucosamine at concentrations above 20mm caused a greater than 50% inhibition of the incorporation of l-[G-(3)H]fucose and l-[U-(14)C]serine. 4. Carbohydrate content of the purified secretions was approximately 50% and consisted principally of galactose, N-acetylglucosamine, N-acetylgalactosamine, fucose and sialic acids. 5. Chromatography on DEAE-cellulose and Bio-Gel A-150m and equilibrium density-gradient centrifugation in a CsCl gradient confirmed the presence of mucous glycoproteins. 6. Electrophoresis on 1% agarose gels gave profiles that were identical with canine respiratory mucus obtained in vivo. 7. These results support the utility of the explant system for studies of respiratory secretions.
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D004285:Dogs; D005643:Fucose / Q000378:metabolism; D005688:Galactosamine / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism / Q000494:pharmacology; D006023:Glycoproteins / Q000096:biosynthesis*; D009077:Mucins / Q000096:biosynthesis; D009093:Mucus / Q000378:metabolism; D009438:Neuraminic Acids / Q000378:metabolism; D009646:Norleucine / Q000494:pharmacology; D009924:Organ Culture Techniques; D010042:Ouabain / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism*; D011691:Puromycin / Q000494:pharmacology; D012140:Respiratory Tract Diseases / Q000378:metabolism; D014132:Trachea / Q000378:metabolism*; D014316:Tritium
chemical_list: D006023:Glycoproteins; D009077:Mucins; D009438:Neuraminic Acids; D011498:Protein Precursors; D014316:Tritium; D005643:Fucose; D011691:Puromycin; D010042:Ouabain; D005688:Galactosamine; D009646:Norleucine; D005944:Glucosamine; D005690:Galactose