MNNG诱发新生大鼠腺胃癌模型的建立及其在胃癌发病机制研究上的应用

通过给新生Ｗｉｓｔａｒ大鼠连续１０次（每日１次）１－甲基－３－硝基－１亚硝基肌（ＭＮＮＧ）灌胃，成功地诱发出腺胃癌、腺瘤和异型增生等病变。在０．４ｍｇ／只剂量组，这三种病变的诱发率分别为３９％、５０％和１００％，腺胃癌的诱发率与ＭＮＮＧ剂量成正比，雄性大鼠高于雌性（Ｐ＜０．０２），７０％病变发生在胃窦部。本模型具有致癌物用量小、易定量、给药期短、省时省力和不易污染环境等优点。研究还发现６个腺胃癌中有４个ＤＮＡ具有使ＮＩＨ／３Ｔ３发生恶性转化的作用，这种转化表现为对Ｂａｌｂ／ｃ裸鼠有致瘤性，提示在这种腺胃癌ＤＮＡ中存在转化基因。     

中国胃癌高发县鱼露的致突/致癌性研究

通过生物学短期试验和动物诱癌实验,我们研究了我国胃癌高发区福建长乐县(男性胃癌标化死亡率达113.20/10~5)鱼露的致突致癌作用。结果表明,鱼露经亚硝化后其乙酸乙酯萃取物具有明显的直接诱发S.typhimurum TA100回变、诱发V79细胞姐妹染色单体交换(SCE)和微核:诱发大肠杆菌PQ37SOS、使小牛胸腺DNA烷化的作用,并且能诱导人正常胃粘膜细胞DNA程序外合成(UDS),给新生Wistar大鼠灌胃后第四周和第十六周分别发现能诱发腺胃粘膜不典型增生(5/5)和腺胃癌(1/5);而未经亚硝化鱼露无此作用或作用很弱。进一步分析发现亚硝化鱼露中有N-亚硝酸胺(30,9-6.04μm),这类直接致灾致癌物的存在可能是亚硝化鱼露致突致癌作用的原因。长期食用鱼露可能与当地胃癌高发有关。     

MUTAGENICITY AND CARCINOGENICITY OF FISH SAUCE FROM A COUNTY WITH THE HIGH RISK FOR GASTRIC CANCER IN CHINA

The mutagenicity and carcinogenicity of fish sauce (FS) sample from Changle County, a high gastric cancer mortality (113.20/105) area, were investigated with the biologic short-term tests and laboratory animal experiment. The results showed that the extract of FS was markedly direct mutagenic toward S. typhimurium TA100, induced high sister chromatid exchanges (SCE) and micronucleus (MN) in V79 cells after nitrosation with sodium nitrite. But the non-nitrosated FS did not. The nitrosated fish sauce (NFS) also induced SOS in E. coli PQ37 and alkylation of calfthymus DNA. The potency of NFS to induce unscheduled DNA synthesis (UDS) in human normal gastric mucosal cells was increased about fivefold compared with FS. When the NFS extract was given to newborn rats by gavage, dys-plasia and adenocaroinoma were induced in the glandular stomach in the 4th and 16th experimental week, respectively. N-nitrosamides were also found in NFS, which may account for the mutagenicity and carcinogenicity of NFS. It is indi     

MNNG诱发新生大鼠腺胃癌模型的建立及其在胃癌发…

通过给新生Ｗｉｓｔａｒ大鼠连续１０次（每日１次）１－甲基－３硝基－１亚硝基胍（ＭＮＮＧ）灌胃，成功地诱发出腺胃癌、腺瘤和异型增生等病变。在０．４ｍｇ／只剂量组，这三种病变的诱发率分别为３９％、５０％和１００％，腺胃癌的诱发率与ＭＮＮＧ剂量成正比，雄性大鼠高于雌性（Ｐ＜０．０２），７０％病变发生在胃窦部。本模型具有致癌物用量小、易定量、给药期短、省时省力和不易污染环境等优点。研究还发现６个腺胃癌中有