胃液中微生物参与N－亚硝酰胺合成的初步研究  

Preliminary Studies on Microbe-mediated N-nitrosamide synthesis

作　　者：潘凯枫[1] 邓大君[1] 李彤[1] 王儒明 周彤[1] 周静[1] 沈德宜 

机构地区：[1]北京市肿瘤防治研究所,北京医科大学临床肿瘤学院

出　　处：《中华预防医学杂志》1995年第4期222-224,共3页Chinese Journal of Preventive Medicine

基　　金：卫生部青年科学基金资助项目

摘　　要：为探讨Ｎ－亚硝酰胺内源性合成途径，利用Ｎ－亚硝酰胺痕量分析法，以Ｎ－甲基－Ｎ－亚硝基脲为代表物，对Ｎ－亚硝酰胺的化学合成和胃内分离培养出的微生物对化学合成的影响进行了研究。结果表明：以甲基脲（０．４２ｍｍｏｌ／Ｌ）和亚硝酸钠（２５ｍｍｏｌ／Ｌ）为前体、在模拟人胃内条件进行Ｎ－甲基－Ｎ－亚硝基脲（ＭＮＵ）合成时，反应体系的ｐＨ值对ＭＮＵ合成有重要影响，ｐＨ≤３时化学合成最多。对从胃癌高发区患者胃内分离培养出的微生物进行催化ＭＮＵ合成能力研究，发现绿脓杆菌在ｐＨ值６～７时具有催化ＭＮＵ合成作用，具有催化活性的成分为存在于活菌体上的热不稳定物质。hemical synthesis of N-nitrosamide and influences on it by bacteria and fungi isolated from human gastric juice were studied with trace analysis method to explore the pathway of its endogenous forma-tion. Results showed in synthesis of N-methyl-N-nitrosourea(MNU)with precursors of methylurea(0.42mmol/L)and sodium nitrite(25mmol/L) in a condition simulating human stomach, pH of the re-action system played an important role in the synthesis,the amount of synthetic chemical maximized at a pH of 1-3 and almost no synthesis was found at pH of 5-7.A study on the ability to synthesize MNU catalyzed by bacteria isolated from the patients with stomach cancer living in a high-risk area showed its synthesis could be accelerated by Pseudomonas aeruginosa at pH of 6-7 with its catalyzing activity exist-ed in heat liable component of living bacteria,This is the first report showing microorganisms to catalyze the formation of N-nitrosamide from its precursors.

关 键 词：胃肿瘤 N-亚硝酰胺 微生物 胃液 合成 

分 类 号：R735.202[医药卫生—肿瘤]