研究锐钛矿型纳米二氧化钛(aNTiO2)的致癌性,将F344/DuCrlCrlj大鼠暴露于浓度为0、0.5、2和8mg/m3的aNTiO2气溶胶。将大鼠分为2组:致癌性研究组暴露两年,卫星研究组暴露一年,然后恢复1天,26周,暴露结束后52周。在致癌性组中,在两名暴露于8mg/m3的男性中观察到细支气管肺泡癌,通过Peto\的测试显示出增加的趋势。然而,该发生率处于JBRC历史控制数据的上限.在0、0.5、2和8mg/m3暴露的雌性的1、2、3和4只大鼠中观察到支气管肺泡腺瘤,并且没有统计学意义。然而,8mg/m3暴露女性的发病率超过了JBRC的历史对照数据.因此,我们得出的结论是,aNTiO2在大鼠中的致癌性有模棱两可的证据。在卫星组中没有观察到肺肿瘤。在致癌性和卫星组中,暴露的男性和女性均观察到颗粒诱导的非肿瘤性病变(肺泡上皮增生和局灶性纤维化)。在8mg/m3暴露的致癌性组中观察到支气管肺泡灌洗液的肺重量和嗜中性粒细胞增加。与暴露结束后1天相比,暴露结束后26周沉积在卫星组大鼠肺中的aNTiO2减少。暴露结束后52周,暴露结束后26周的下降水平相同.
To investigate the carcinogenicity of anatase-type nano-titanium dioxide (aNTiO2), F344/DuCrlCrlj rats were exposed to aNTiO2 aerosol at concentrations of 0, 0.5, 2, and 8 mg/m3. The rats were divided into 2 groups: carcinogenicity study groups were exposed for two years, and satellite study groups were exposed for one year followed by recovery for 1 day, 26 weeks, and 52 weeks after the end of exposure. In the carcinogenicity groups, bronchiolo-alveolar carcinomas were observed in two 8 mg/m3-exposed males, showing an increasing trend by Peto\'s test. However, this incidence was at the upper limit of JBRC\'s historical control data. Bronchiolo-alveolar adenomas were observed in 1, 2, 3, and 4 rats of the 0, 0.5, 2, and 8 mg/m3-exposed females and were not statistically significant. However, the incidence in the 8 mg/m3-exposed females exceeded JBRC\'s historical control data. Therefore, we conclude there is equivocal evidence for the carcinogenicity of aNTiO2 in rats. No lung tumors were observed in the satellite groups. Particle-induced non-neoplastic lesions (alveolar epithelial hyperplasia and focal fibrosis) were observed in exposed males and females in both the carcinogenicity and satellite groups. Increased lung weight and neutrophils of bronchoalveolar lavage fluid were observed in the 8 mg/m3-exposed carcinogenicity groups. The aNTiO2 deposited in the lungs of the satellite group rats was decreased at 26 weeks after the end of exposure compared to 1 day after the end of exposure. At 52 weeks after the end of exposure, the decreased level was the same at 26 weeks after the end of exposure.