Subchronic cigarette smoke inhalation studies in inbred syrian golden hamsters that develop laryngeal carcinoma upon...

Inbred BIO 15.16 Syrian golden hamsters were exposed for 6-20 weeks to smoke from three types of experimental cigarettes. The incidence and severity of laryngeal hyperplasia increased in these hamsters, a few (2) laryngeal papillomas appeared, alveolar macrophages became more frequent and aggregated, and hyperplasia of terminal bronchiolar epithelium occurred. This subchronic response of hamsters to smoke markedly differed for the three types of cigarettes. Statistical evaluation of the data by log linear models proved these differences to be significant. At equal doses of smoke, the most severe response was caused by an all-tobacco cigarette. The weakest subchronic effects, next to those seen in the negative control group, were elicited by smoke from a cellulose-derived tobacco supplement. The effects of smoke from a 1:1 blend of the two smoking materials were intermediate. The severity of the subchronic response of the respiratory tract paralleled the extent of malignant transformations of the larynx previously observed in the same animal model with the same three types of cigarettes in chronic inhalation studies.