This research studies the effect of inorganic sulfates (known to cause experimental bronchitis) on the rat trachea from a biochemical and histological viewpoint. Changes in the uptake of radioactive sugar and amino acid precursors into specific glycoprotein fractions as separated by column chromatography are monitored during and following exposure to sulfur dioxide or sulfuric acid. Complete chemical analyses of the effected fraction(s) are carried out. We wish to: 1) study the progressive changes in mucin biochemistry upon in vivo and in vitro exposure of the trachea to the sulfate; 2) elucidate the mechanism of action of the sulfate in producing these changes; and 3) correlate these biochemical changes to histochemical changes in the tracheal epithelium. Answering these questions will lead to greater understanding of the complex processes occurring in the tracheo-bronchial lining during experimental chronic bronchitis.