Lu S H, Ohshima H, Bartsch H
IARC Sci Publ. 1984(57):947-53.
Possible etiological factors involved in oesophageal cancer in various parts of the world and in certain provinces in Northern China are summarized. Evidence is accumulating that N-nitroso compounds and their precursors are involved in the disease in Northern China, as shown in a recent study: excretion of urinary N-nitrosamino acids by inhabitants living in a high- (Linxian) and in a low-risk area (Fanxian) for oesophageal cancer was compared. Linxian subjects excreted significantly more nitrate and nitrosamino acids (N-nitrosoproline, N-nitrosothiazolidine-4-carboxylic acid, N-nitrososarcosine) than those in Fanxian. When Linxian subjects were given 100 mg vitamin C three times a day (after each meal) together with proline, the level of urinary N-nitrosamino acids was reduced to that found in Fanxian. Thus, vitamin C, an efficient inhibitor of endogenous nitrosation, should now be examined in intervention trials in subjects in whom endogenous formation of N-nitroso compounds is elevated.
总结了世界各地及中国北方某些省份食管癌可能的病因。越来越多的证据表明，N-亚硝基化合物及其前体与中国北方的食管癌发病有关，如最近一项研究所示：比较了食管癌高风险地区（林县）和低风险地区（范县）居民尿中N-亚硝基氨基酸的排泄情况。林县居民排泄的硝酸盐和N-亚硝基氨基酸（N-亚硝基脯氨酸、N-亚硝基噻唑烷-4-羧酸、N-亚硝基肌氨酸）明显多于范县居民。当给林县居民每天三次（每餐饭后）服用100毫克维生素C并同时服用脯氨酸时，尿中N-亚硝基氨基酸水平降至范县居民的水平。因此，内源性亚硝化作用的有效抑制剂维生素C，现在应该在体内N-亚硝基化合物形成增加的受试者中进行干预试验。
