Effect of Cigarette Smoke and Its Constituents on Ciliated Mucus-Secreting Epithelium2

One of the properties of cigarette smoke is its ability to interfere with the normal function of ciliated, mucus-secreting epithelium. The effect is manifested primarily by a slowing of the rate of mucous flow, quantitative changes in mucous secretion, and qualitative changes in mucous consistency. The effect of cigarette smoke is dependent upon its aerosol nature as well as its chemical composition. Reduction in the quantity of aerosols in cigarette smoke results in a reduction in the intensity of the response of the epithelium. At all levels of aerosol production, however, a response is elicited. Filtration of smoke is capable of obviating the response only when it is sufficiently efficient to retain all particulate matter so that gas-phase material alone results. This gas phase, in the concentrations studied, produces no significant effect on the epithelium. It is well to emphasize that during this state the term “smoke” is not applicable. A study of the individual components in cigarette smoke demonstrates that both alkaloids and other chemical compounds are effective in producing the response. The application of an aqueous solution of tars, which were collected from filters, results in the inhibition of mucous flow typically seen with whole cigarette smoke. The accumulation and retention of particulate matter deposited on the epithelium is facilitated by the demonstrated adverse effect of cigarette smoke on the epithelium. This observation suggests a role for cigarette smoking in the pathogenesis of pulmonary cancer.