Zhu S T, Liu Z C
Harbin Medical University.
Zhonghua Yu Fang Yi Xue Za Zhi. 1990 Mar;24(2):83-5.
N-Nitrosodimethylamine (NDMA) is a potential carcinogen and present in our surroundings widely. NDMA can be formed by many precursors, Dimethylamine (DMA) is the most common precursor in food. To evaluate the risk of DMA nitrosation in vivo, so that men can do their best to reduce endogenous nitrosamine exposure, we carried out this research. This paper is the first part of our research. The stabilities of DMA and nitrite in the stomach were studied. DMA was stable and nitrite was decomposed at the speed of second-order reaction. The stabilities of nitrite in simulate gastric acid and in ascorbic (VC) solution also were studied. Nitrite decomposition in simulate gastric acid was very similar to the one in the stomach. VC solution at the equimolar with nitrite can decompose 53-79% of nitrite in one minute with shaking. We suggested that the efficiency of VC inhibiting endogenous nitrosation can be estimated on the basis of decomposing speed of nitrite and nitrosating speed by nitrite.
N-亚硝基二甲胺（NDMA）是一种潜在致癌物，广泛存在于我们的周围环境中。NDMA可由多种前体物质形成，二甲胺（DMA）是食物中最常见的前体物质。为评估体内DMA亚硝化作用的风险，以便人们尽力减少内源性亚硝胺暴露，我们开展了本研究。本文是我们研究的第一部分。研究了DMA和亚硝酸盐在胃中的稳定性。DMA稳定，亚硝酸盐以二级反应速度分解。还研究了亚硝酸盐在模拟胃酸和抗坏血酸（VC）溶液中的稳定性。亚硝酸盐在模拟胃酸中的分解与在胃中的分解非常相似。与亚硝酸盐等摩尔的VC溶液在振荡条件下一分钟可分解53%-79%的亚硝酸盐。我们建议可根据亚硝酸盐的分解速度和亚硝酸盐的亚硝化速度来评估VC抑制内源性亚硝化作用的效率。
