Abstract
Following an introductory survey of the literature concerning the induction of bronchial cancer in laboratory animals after exposure to cigarette smoke or intrapulmonary application of smoke condensates, a method is described for a single pertracheal instillation of smoke condensate into peripheral areas of the bronchial system of rats. Histological examination of the lungs showed the appearance of intrapulmonary foreign body granulomas and squamous cell metaplasia of the bronchial epithelium. According to the experiences of oncology, the lack of neoplastic reactions in spite of the 10 months’ duration of the experiments might be explained by the small dosages which had to be limited due to the applied technique. As far as we know at present, the possible maximum carcinogenic potency of the smoke condensates applied is only about 1/100 of those dosages of pure carcinogens which, according to the literature, are sufficient to cause bronchial carcinoma in rats. For technical reasons it seems recommendable for further in vivo studies with lung tissue to use concentrated tobacco smoke condensate or its fractions.