论文部分内容阅读
目的评价6种具有致突变作用的空气燃烧排放提取物的致肺癌作用.方法用CD-1小鼠肺瘤生物测试方法,在小鼠断奶前处理受试物3次,6个月后观察肿瘤的发生率和病理组织学改变.并以苯并芘作为阳性对照.结果 6种具有突变作用的空气燃烧排放提取物均具有致肺癌作用,并呈剂量-效应关系,另外发现其致肺癌作用与其中是否含二氯甲烷无关.“,”AIM To evaluate lung tumorigenicity of six mutagenic complex mixtures extracted from combustion effluents or tar in a preweanling CD-1 mouse bioassay. METHODS Newborn mice were injected ip with test complex mixture sample in a total volume of 35 μL DMSO vehicle three times over a two-week-period. Potent carcinogen, benzo[a]pyrene, used as the positive control. Mice were sacrificed at 26 weeks of age and surface lung tumors were counted in the separated lobes of the Formalin-fixed lungs. Sections of lung tumors were stained with hematoxylin-eosin for histopathologic evaluation. RESULTS Four mixture samples extracted from a natural gas flame doped with high or low amounts of toluene in the presence or absence of methylene chloride were found to be tumorigenic as compared to the vehicle-controls. The two high-toluene mixture samples induced more lung tumors(64%-76%) than tumors(43%-45%) induced by two low-toluene mixtures on a weight basis (700 μg/animal). The presence or absence of methylene chloride did not significantly alter lung tumor incidence. A mixture sample (WSR-30) extracted from an ethylene-fueled jet-stirred reactor induced a dose-dependent increase in lung tumor incidence over a total dose range of 140-700 μg/animal. An extract mixture of tar from pyrolyzed wood (sweet gum) was also found to be tumorigenic in the bioassay. CONCLUSION Six mutagenic complex mixtures extracted from combustion effluents or tar are lung tumorigenic in the preweanling CD-1 mouse bioassay.