Effects of cigarette smoke residue on rabbit tracheal epithelium in organ culture.

The effects of tobacco cigarette smoke residues on rings of rabbit tracheal epithelium in organ culture were examined. Residue from cigarette smoke was collected through continuous suction and the residue from one cigarette was used for each two tracheal rings. Epithelium exposed to residue showed cellular desquamation, initially of only scattered columnar cells. As exposure time increased the entire columnar cell layer was lost, resulting in exposure of basal cells to residue. Columnar cell loss occurred through breakdown of intercellular junctions. Alteration was also observed in columnar cell mitochondria, cilia, and microvilli. Loss of columnar cells and subsequent exposure of basal cells to tobacco smoke residue may account for the hyperplasia and metaplasia observed by other investigators after long-term in vivo exposure of tracheal epithelium to cigarette smoke.