Pathological alterations in Syrian golden hamster lungs after passive exposure to cigarette smoke.

The effects of 2 types of research cigarettes, differing in their total smoke delivery and condensate, were examined as to their histopathological effects of Syrian golden hamster lungs. The animals were passively exposed to the total smoke of the cigarettes once a day, 5 days/week for 1 year. Experimental and control animals were killed one day after termination of exposure. Varying effects on the macrophages of pulmonary alveolar tissue were observed. Infiltration of lung tissue by "Brown cells" was a common pathological alteration. Qualitative and quantitative differences existed between the two cigarette groups with respect to the occurrence of such "Brown cell" clumps. The response of the lung tissue to smoke exposure would appear to be dependent upon the amount of mainstream total particulate matter (TPM), the amount of condensate, the time exposed and the number of cigarettes.