Guo N, Conaway C C, Hussain N S, Fiala E S
American Health Foundation, Valhalla, NY 10595.
Carcinogenesis. 1990 Sep;11(9):1659-62. doi: 10.1093/carcin/11.9.1659.
The hepatocarcinogens 2-nitropropane and acetoxime have previously been found to induce a specific and qualitatively identical pattern of base damage in rat liver DNA and RNA, including the induction of increased levels of 8-hydroxyguanine. Because both 2-nitropropane and acetoxime are weaker carcinogens in female rats than male rats, we examined the ability of these chemicals to induce this pattern of damage in liver and kidney nucleic acids of male and female Sprague-Dawley rats 6 and 18 h after administration. Significantly lower levels of 8-hydroxydeoxyguanosine, 8-hydroxyguanosine and other presumed modified nucleosides discernible by high-performance liquid chromatography with electrochemical detection were found in liver nucleic acids of female rats at both time points. In addition, minimal alteration of nucleic acids was observed in the kidney, which is not a target organ for the carcinogenicity of either 2-nitropropane (2-NP) or acetoxime (ACO). These results support the hypothesis that the specific DNA alterations observed are relevant to the hepatocarcinogenicity of 2-NP and ACO.
此前已发现肝癌致癌物2-硝基丙烷和丙酮肟可在大鼠肝脏DNA和RNA中诱导出一种特定且性质相同的碱基损伤模式,包括诱导8-羟基鸟嘌呤水平升高。由于2-硝基丙烷和丙酮肟在雌性大鼠中的致癌性均弱于雄性大鼠,我们检测了这些化学物质在给药后6小时和18小时诱导雄性和雌性Sprague-Dawley大鼠肝脏和肾脏核酸出现这种损伤模式的能力。在两个时间点,雌性大鼠肝脏核酸中8-羟基脱氧鸟苷、8-羟基鸟苷以及其他通过高效液相色谱-电化学检测可识别的假定修饰核苷的水平均显著较低。此外,在肾脏中观察到核酸变化极小,而肾脏并非2-硝基丙烷(2-NP)或丙酮肟(ACO)致癌作用的靶器官。这些结果支持了以下假说,即所观察到的特定DNA改变与2-NP和ACO的肝癌致癌性相关。