跟研究亚硝胺致癌活性问题相反,对亚硝酰胺可能是致癌物这种复杂性直至最近几年仍然兴趣不大,而对脲、脲烷和胍的N-亚硝基衍生物已作了长时间的研究,只是最近几年才指出N-亚硝基-N-甲基乙酰胺和N-亚硝基-N-甲基苯酰胺大部分是在动物的胃肠道引起肿瘤。相对于需要酶的代谢活化的亚硝胺致癌物,亚硝酰胺是近致癌物。对亚硝酰胺致癌性研究容易忽略,可归因于如下一些原因。研究者推测:亚硝酰胺稍受热(<100℃)而引起的化学不稳定性和光解,使得在一般环境条件下处理它们变得非常困难(但不是不可能),因而不引起人们的注意。我们可以指出:在另一方面,亚硝胺是异常稳定的,例如,N-亚硝基二烷基胺能从20％氢氧化钠或浓硫酸溶液中回收而不变化。亚硝胺的生物学活性是因为α-羟基化 Contrary to the research on the carcinogenic activity of nitrosamines, the complexity that nitrosamides may be carcinogens has remained largely uninterested in recent years, and N-nitroso derivatives of urea, urethane and indole have been made. Long-term studies have only pointed out in recent years that N-nitroso-N-methylacetamide and N-nitroso-N-methylbenzamide mostly cause tumors in the gastrointestinal tract of animals. Nitrosamides are near-carcinogens relative to nitrosamine carcinogens that require the metabolic activation of enzymes. Studies on the carcinogenicity of nitrosamines are easily overlooked and can be attributed to the following reasons. The investigators speculate that the chemical instability and photolysis caused by the slight heat (<100°C) of nitrosamines makes it very difficult (but not impossible) to handle them under normal environmental conditions and therefore does not attract people’s attention. We can point out that on the other hand, nitrosamines are exceptionally stable. For example, N-nitrosodialkylamines can be recovered from 20% sodium hydroxide or concentrated sulfuric acid solutions without change. The biological activity of nitrosamines is due to alpha-hydroxylation