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亚硝胺是一类公认的食管癌化学致癌物。它们广泛存在于人类生存环境中(外源性亚硝胺),也可在一定条件下于人体内合成(内源性亚硝胺)。我国通过控制人群外源性亚硝胺暴露的措施,并未使食管癌发病率明显下降,故内源性亚硝胺诱发人类食管癌的作用可能强于外源性亚硝胺。内源性合成是人体亚硝胺的主要来源,且内源性亚硝胺可致人类食管癌,因而减少人体内源性亚硝胺的暴露可成为食管癌一级预防的重要措施。关于内源性亚硝胺与食管癌预防的可能研究方向总结如下:①减少亚硝胺底物的摄入及形成、抑制亚硝胺合成反应可减少内源性亚硝胺的暴露;②亚硝胺在体内的吸收过程可能为被动扩散,干预其吸收过程仍存在困难;③亚硝胺本身不致突变,其致突变活性决定于其在体内的代谢或诱导产物,故抑制亚硝胺体内代谢活化也可能抑制食管癌的发生。
Nitrosamine is a recognized class of chemical carcinogens in esophageal cancer. They exist widely in human living environment (exogenous nitrosamines), but also under certain conditions in the human body synthesis (endogenous nitrosamines). Our country through the control of exogenous nitrosamines exposure measures, did not significantly reduce the incidence of esophageal cancer, endogenous nitrosamines induced esophageal cancer may be stronger than exogenous nitrosamines. Endogenous synthesis of nitrosamines is the main source of human and endogenous nitrosamines can cause human esophageal cancer, thus reducing the exposure of endogenous nitrosamines can be an important measure for the prevention of primary esophageal cancer. The possible research directions on the prevention of endogenous nitrosamines and esophageal cancer are summarized as follows: (1) reducing the intake and formation of nitrosamines and inhibiting the synthesis of nitrosamines can reduce the exposure of endogenous nitrosamines; Nitrosamines in vivo absorption process may be passive diffusion, intervention in its absorption process is still difficult; ③ nitrosamine itself will not be mutated, its mutagenic activity depends on its metabolism in the body or induced products, it inhibits nitrosamines in vivo metabolism Activation may also inhibit the occurrence of esophageal cancer.