二甲基亚硝胺与大鼠肝组织DNA形成加合物的定量研究

QUANTITATIVE STUDY ON THE FORMATION OF DNAO^6 -METH YLGUANINE IN THE HEPATIC OF RATS INDUCED BY N-NITROSODM ETHYLAMINE

作者应用免疫组化技术结合图象分析技术,对二甲基亚硝胺(N-nitrosodimethylamine,NDMA)诱导大鼠肝脏DNAO^6-甲基鸟嘌呤(Omethylguanine,OmG)作了定性和定量研究。分别给大鼠一次腹腔注射NDMA1,2,3,5,10,30,50mg/kg,5小时后大鼠肝脏产生O(?)mG显示明显的剂量反应关系和细胞特异性。肝组织中细胞产生O(?)mG的量与NDMA的剂量间呈幂函数关系,二者呈正相关;产生O(?)mG的细胞数与NDMA的剂量间呈指数函数关系,二者呈正相关。肝细胞、肝小叶中央静脉和肝窦内皮细胞显示O(?)mG阳性。

Recent year immunohistochemistry have been developed and used in -the localization of nitrosamine-induced DNA adducts. We have first used double PAP method and image analysis technique to quantitatively determine N-nitrosodimethylamine (NDMA)-induced O6-methylguanine(O6-mG)in the DNA of rat hepatic tissue.Male Wistar rats treated with a single i.p.dose of NDMA(1,2,3,5,10,30,50 mg/kgbw respectively).The formation of O6-mG showed significant dose- relationship and cell specificity in the hepatic tissue' of rats five hours after injection . The production of O-mG in target cells was related to the dose of NDMA in power founction curve. The number of O6 - mG positive cells in hepatic tissue was related to the dose of NDMA in an index curve. O6-mG was visualized in the hepatocyte, central venous and sinusoidal endothelial cells.