Tannenbaum S R
Int J Vitam Nutr Res Suppl. 1989;30:109-13.
N-Nitroso compounds are known to form endogenously in the human stomach from the precursors nitrite as well as secondary and tertiary amines. Ascorbic acid has been found to be an effective blocking agent for this process of formation of carcinogenic substances, both in vitro and in vivo. The mechanism by which ascorbic acid reacts is chemical in nature and results in the formation of NO and dehydroascorbic acid. Since NO can be recycled in the presence of O2 to form [NO]x, which is capable of additional nitrosation, greater than stoichrometric amounts of ascorbate are required for effective inhibition in vivo. The efficacy of ascorbic acid for inhibition of nitrosamine formation in humans has been demonstrated both clinically and epidemiologically through the use of "Nitrosoproline Test"--of Ohshima and Bartsch.
已知N-亚硝基化合物在人体胃内由亚硝酸盐以及仲胺和叔胺等前体物质内源性形成。已发现抗坏血酸在体外和体内都是这种致癌物质形成过程的有效阻断剂。抗坏血酸发生反应的机制本质上是化学性的，会导致一氧化氮（NO）和脱氢抗坏血酸的形成。由于在有氧气存在的情况下NO可以循环形成能够进行额外亚硝化作用的[NO]x，因此在体内有效抑制需要大于化学计量的抗坏血酸盐。通过使用大岛和巴尔施的“亚硝基脯氨酸试验”，已在临床和流行病学上证明了抗坏血酸对人体亚硝胺形成的抑制功效。
