کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2588255 | 1130959 | 2007 | 7 صفحه PDF | دانلود رایگان |
The N-nitroso derivative of an extensively used insecticide, propoxur, consistently induced dose-responsive chromosome aberrations and sister-chromatid exchanges (SCEs) in Chinese hamster ovary (CHO-W8) cells. Further investigations indicated that post-treatment incubation with a regular 1.5-cell-cycle period did not offer an unbiased estimation of the genotoxicity of N-nitroso carbamate insecticides. The scale of chromosome aberration induction increased with extension of the post-treatment incubation period. Comparable phenomena were not found in CHO-AGT cells proficient for O6-methylguanine-DNA-methyltransferase. In CHO-W8 cells, pulsed-treatment of the insecticide in the 1st replication cycle showed higher SCE induction than in the 2nd cycle. Similar phenomenon was also found in SCE induced by N-nitroso derivatives from other carbamate insecticides including aldicarb, carbofuran and methomyl. Treated cells did not show significantly perturbed cell cycle progression until 12 h after treatment removal. Based on the above observations, the O6-methylguanine-DNA adduct is suggested to be the major lesion caused by the delayed genotoxic effect of N-methyl carbamate insecticides as described in this report.
Journal: Food and Chemical Toxicology - Volume 45, Issue 6, June 2007, Pages 928–934