ABSTRACT
Pieces of tissue were obtained from lungs removed surgically from patients who were long-term cigarette smokers. The lung tissue was placed in culture medium containing 35SO4 or 3H glucosamine and exposed to 95% O2 and 5% CO2 at 37 degree C for varying periods of time. The tissue was then fixed and autoradiographs prepared. Autoradiographs performed after four hours' incubation with the radio-isotope demonstrated a large number of grains in the lumen of the bronchioles with a lesser number of grains over the epithelial cells. Pulse chase studies showed migration of the labelled material from a paranuclear location to the lumen during the four-hour period of incubation. The study provides evidence for mucus secretion by the epithelium of the bronchioles of cigarette smokers.
