吡草醚原药大鼠慢性毒性与致癌试验病理观察

目的 通过病理学观察探讨吡草醚原药对大鼠的慢性毒性与致癌作用.方法 按照GB15670-1995《农药登记毒理学试验方法》进行大鼠慢性毒性与致癌性合并试验,样本经10％中性福尔马林固定,脱水,石蜡包埋,切片,HE染色,树胶封固,光镜检查.结果 慢性毒性实验高剂量组肾小管上皮细胞变性高于对照组,与对照组之间有极显著性差异（P≤0.01）；中剂量组肾脏间质炎高于对照组,与对照组之间有显著性差异（P≤0.05）；低剂量组肾脏病理变化与对照组之间无显著性差异.其他病变各组之间均无显著性差异.致癌性试验,肿瘤发生率统计学上无显著性差异.该受试物对肿瘤的潜伏期没有影响；多发性肿瘤的发生各组之间没有差异.结论 未发现该药物对SD大鼠的致癌性.慢性毒性表现出一定的雌雄差异,肾脏是其主要靶器官.

Experimental Pathologic Observation on Chronic Toxicity and Carcinogenicity of Pesticide

Objective To explore the chronic toxicity and carcinogenicity of pesticide pyraflufen-ethyl in rats. Methods According to National Standards of ＂Toxicological Methods of Pesticides for Registration＂ （GB15670-1995 of PRC） , chronic toxicity tests and carcinogenieity tests were conducted. These samples were fixed in 10% neutral formalin firstly. Then the samples were embedded in paraffin after dehydration process. Afterward, the samples were sectioned and stained by hematoxylin-eosin（HE） staining. Finally, the sections were cemented by gum and observed in light microscope. Results Chronic toxicity tests revealed that the degeneration ratio of renal tubular epithelial cells in high dosage group was significantly increased comparing to control group （P≤0. 01 ）. Furthermore, the middle dosage group results showed there was a similar increasing in the proportion of tubulointerstitial nephritis （P~〈0.05） , however, there were no evident renal pathology differences between low dosage group and control group. In addition, other pathological changes in any dosage group were not remarkably different from control groups. Statistical incidence variance of tumor, multiple primary neoplasms and tumor latency in different groups were not observed in carcinogenicity tests. Conclusion We found that the main target organ was kidney and sexual differences existed in chronic toxicity, in addition, the tumorigenesis of rats would not be elevated by Pyraflufen-ethyl.