【摘要】 为筛选遗传毒胃致癌物,我们以N-甲基-N′-硝基-N-亚硝基胍(MNNG)为模型诱变剂,发展大鼠胃粘膜微核试验。Wistar大鼠经口给以MNNG灌胃2次,间隔24h,末次染毒后24h处死。取腺胃,以1％链霉蛋白酶E于37℃消化30～45min,离心消化液收集胃粘膜细胞,制片,Giemsa染色。胃粘膜细胞收率为每鼠4.0 ×10~6细胞。在涂片上,胃粘膜细胞可分为3组:表面上皮细胞、泌酸细胞、腺颈细胞和酶原细胞。研究结果表明:MNNG可引起大鼠胃粘膜细胞微核率增加,并有剂量一效应关系。更多还原

【Abstract】 Gastric carcinoma is one of the common cancer in human. We developed the micronucleus assay of gastric mucosal cells (GMC) in rat in order to screen the genotoxic stomach-carcinogens N-Methyl -N’-nitro-N-nitrosoguanidine (MNNG) was given twice to wistar rats by oral gavage with 24 h interval. The rats were killed at 24 h after the last treatment. The glandular stomach was filled up with the enzyme solution(1.0% pronase E)and digested for 30-45 min in 37℃. The GMC were collected by centrifuge, smeared and stained with Giemsa.The yields of GMC was approximately 4 × 106 cells per rat. The GMC in smears were divided into three groups : the surface epithelial cells (34%), parietal cells(22%), mucous neck cells and chief cells(43%) .The frequencies of micronucleated GMC were 0.40, 1.60, 2.20 and 6.60‰ respectively at the dose of MNNG 0, 25, 50 and 100 mg/ kg. At the double dose of MNNG 50 mg/kg and 24, 48 and 72 h sample time, the micronucleus frequencies of GMC were 2.60, 2.80 and 0.60 ‰ respectively. the results indicated that MNNG induce a dose-dependant increase of micronucleus frequencies of GMC.更多还原