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亚硝基化合物代表一组对动物和人致突变、畸变和癌变的作用剂。在人胃肠道的各个部位已发现相当数量的亚硝基化合物及其前体物,而且这些物质可被粘膜吸收。亚硝基化合物的致突变作用在很大程度上取决于组织的代谢活性。这些组织实际上将亚硝胺转变为致突变代谢物,后者作用于细胞的DNA,使DNA合成时引起突变的机率增加。 通常有少量的亚硝基化合物存在于环境中(空气、饮用水、食物等),通过进食或呼吸进入胃内。亚硝基化合物及其代谢物经由肾排出。 已证实在人类胃中可由于含氮前体物—胺和酰胺,尿类和氨基甲酸乙酯的亚硝基化作用,形成亚硝基化合物,特别是在某些适宜的条件下如在胃的硷性pH环境中。已报道pH值接近3.0确实可抑制胃中的
Nitroso compounds represent a group of agents that act on mutagens, aberrations and cancers in animals and humans. A considerable amount of nitroso compounds and their precursors have been found in various parts of the human gastrointestinal tract, and these substances can be absorbed by the mucosa. The mutagenic effect of nitroso compounds depends to a large extent on the metabolic activity of the tissue. These tissues actually transform nitrosamines into mutagenic metabolites, which act on the DNA of the cell and increase the probability of mutations during DNA synthesis. There are usually small amounts of nitroso compounds present in the environment (air, drinking water, food, etc.) that enter the stomach through eating or breathing. Nitroso compounds and their metabolites are excreted through the kidneys. It has been demonstrated that nitroso compounds can form in the human stomach due to the nitrosylation of nitrogenous precursors—amines and amides, urine and ethyl carbamate, especially under certain suitable conditions, such as in the stomach. The alkaline pH environment. It has been reported that a pH of approximately 3.0 can indeed inhibit the stomach