Hypersecretion of mucus glycoproteins in rat airways induced by tobacco smoke.

An animal model of chronic bronchitis has been produced in vivo by exposing rats for 6 weeks to tobacco smoke: the laryngeal and tracheal glands have been studied in vitro by organ culture to analyze glycoprotein precursor incorporation and glycoprotein secretion by individual cells, a feature not previously studied. In the hypertrophied glands produced by tobacco smoke exposure, the cellular rate of glycoprotein secretion was increased. The in vivo administration of phenylmethyloxadiazole (PMO) to rats exposed to tobacco smoke blocked this effect. In vitro analysis of glands from unexposed rats that received PMO showed that it modified cell function directly by reducing the rates both of glycoprotein discharge and or precursor incorporation into intracellular glycoproteins.