Brown B G, Lee C K, Bombick B R, Ayres P H, Mosberg A T, Doolittle D J
Environmental and Molecular Toxicology Division, RJ Reynolds Tobacco Company, Winston-Salem, NC 27102, USA.
Environ Mol Mutagen. 1997;29(3):303-11.
The genotoxic potential of mainstream smoke from a test cigarette (TOB-HT) that primarily heats tobacco and a representative tobacco-burning cigarette (Kentucky reference 1R4F) was compared in male B6C3/F1 mice after nose-only inhalation exposure. Mice were exposed 1 hr per day, 5 days/ week for a 4 week period to mainstream smoke at concentrations of 0, 0.16, 0.32, and 0.64 mg total particulate matter/liter of air. Micronuclei formation in bone marrow and peripheral blood polychromatic erythrocytes (PCE) of animals exposed to either the TOB-HT or 1R4F cigarette was not significantly different compared with control animals exposed nose-only to filtered and humidified air (sham controls). DNA adduct measurement by the 32P-post-labeling method indicated an exposure-dependent increase in lung adducts of animals exposed to 1R4F cigarette smoke at all three concentrations with the mid and high exposure groups exhibiting statistically significant increases (P < 0.05) in adduct formation compared to sham-exposed animals. The concentration of DNA adducts in the lungs of animals exposed to the TOB-HT cigarette was not significantly increased (P < 0.05) at any concentration compared to sham-exposed controls. A statistically significant (P < 0.05) concentration-dependent formation of DNA adducts was also observed in the heart tissues of animals exposed to smoke from the 1R4F cigarette at all three concentrations, but no significant increase in adduct formation was observed in heart DNA of the animals exposed to the TOB-HT cigarette (P < 0.05). Under the conditions of this experiment, the mainstream smoke from the TOB-HT cigarette was demonstrated to be less genotoxic in mice than mainstream smoke from the 1R4F cigarette, which is representative of cigarettes in the current U.S. market.
在雄性B6C3/F1小鼠经仅鼻吸入暴露后，比较了主要加热烟草的测试香烟（TOB-HT）和代表性燃烧烟草香烟（肯塔基参考香烟1R4F）主流烟气的遗传毒性潜力。小鼠每天暴露1小时，每周5天，持续4周，暴露于总颗粒物浓度为0、0.16、0.32和0.64毫克/升空气的主流烟气中。与仅经鼻暴露于过滤和加湿空气的对照动物（假对照组）相比，暴露于TOB-HT或1R4F香烟的动物骨髓和外周血多染红细胞（PCE）中的微核形成没有显著差异。通过32P后标记法进行的DNA加合物测量表明，暴露于1R4F香烟烟雾的动物在所有三个浓度下肺加合物均呈暴露依赖性增加，中、高暴露组与假暴露动物相比，加合物形成有统计学显著增加（P<0.05）。与假暴露对照组相比,暴露于TOB-HT香烟的动物在任何浓度下肺中DNA加合物浓度均未显著增加（P<0.05）。在所有三个浓度下，暴露于1R4F香烟烟雾的动物心脏组织中也观察到DNA加合物形成有统计学显著（P<0.05）的浓度依赖性，但暴露于TOB-HT香烟的动物心脏DNA中加合物形成没有显著增加（P<0.05）。在本实验条件下，证明TOB-HT香烟的主流烟气在小鼠中的遗传毒性低于1R4F香烟的主流烟气，1R4F香烟代表了当前美国市场上的香烟。
