Tobacco Documents Online

! I I I I I I I I I I I I I I I I I ~0 AUTHOR; REZNIK-SCHULLER, HILDEGARD, GERD REZNIK, AND ULTRICH MOHR DATE: 1975 TITLE: EFFECT OF CIGARE'I'rE SMOKE ON THE BRONCHIAL EPITHELIUM OF SYRIAN HAMSTERS: ULTRASTRUCTURAL STUDIES. CITATION: JOURNAL OF THE NATIONAL CANCER INSTITUE 55: No. 2, 353-355 (1975) STUDY DESIGN: Eighteen 12 week old Syrian hamsters, divided into three groups (each group consisted of 3 males and 3 females). The animals in all groups except the controls were exposed to total smoke of two types of unfiltered research cigarettes. For one type of cigarette, the smoke delivery per 30 cig. of mainstream TPM reaching the exposure chamber was 320.27 mg, 2,96 mg nicotine, 37,2 mg DPM and 3.5 g/100 mg CO delivered per cigarette. Two groups of animals exposed to smoke of this cigarette type once a day 5 days/week for 12 months, one group killed 1 day after last smoke exposure, the other group 1 year after the last smoke exposure. The second type of cigarette had a delivery of 93.12 mg mainstream TPM per c 30 cigarettes reaching the exposure chamber; 0.5 mg nicotine, 12.3 mg DPM and 5.32 g/lO0 mg CO delivered per cigarette. One group of animals was exposed once a day 5 days/week for 12 months to smoke of this cigarette type. These hamsters were killed 1 day after the last exposure. The effects of these two types of cigarettes on the bronchial epithelium were examined. RNDINGS/RESULTS: The bronchial epithelia of all smoke-exposed animals were hyperplastic, and their ultrastructure showed invaginations, tilt of nuclear axes, an increase in the number and size of lysosomes and multivesiculated bodies, and increased numbers of enlarged intramitochondrial granules. Squamous metaplasia, rarely found, was present at the stage of filamentous bundle formation. The induced alterations were independent of the type of cigarette used. One year after smoking was terminated, the alterations had neither reversed nor advanced, as compared to those occurring 1 day after the last smoke exposure. CONCLUSIONS: The results demonstrate that the smoke of two types of research cigarettes had the same effects on the bronchial epithelia of Syrian hamsters. From these findings they conclude that the response of the bronchial epithelium to smoke exposure does not depend on the amount of mainstream TPM and condensate of the cigarettes. The alterations described neither reversed nor advanced within 1-year period after termination of smoke exposure. However, the fact that even no minor regenerative processes had begun also indicates that alterations which have reached a stage here described are not reversible. On the other hand, a daily smoke exposure of 1 year did not bring about progressive development from described alterations to bronchial neoplasms.