Meier-Bratschi A, Lutz W K, Schlatter C
Food Chem Toxicol. 1983 Jun;21(3):285-9. doi: 10.1016/0278-6915(83)90062-5.
The extent of formation of N-nitrosodimethylamine (NDMA) in the stomachs of rats and mice after simultaneous oral administration of [14C]dimethylamine and potassium nitrite was determined by measuring the methylation of liver DNA. With doses of around 1 mg dimethylamine hydrochloride/kg body weight and 50 mg potassium nitrite/kg body weight, 0.8% of the amine was nitrosated on average. The individual fluctuations ranged from 0.2 to 1.3% in the rat and from 0.2 to 1.9% in the mouse. Simultaneous administration of 50 mg sodium ascorbate (vitamin C)/kg body weight inhibited the nitrosation by about 80% while 50 mg alpha-tocopherol acetate (vitamin E)/kg body weight reduced the nitrosation by about a half. Assuming similar kinetics and conditions of nitrosation in rats and man, a comparison of the formation of NDMA in vivo from dietary dimethylamine and nitrite with the estimated human uptake of preformed NDMA revealed that in vivo formation in the stomach of man is probably negligible.
通过测量肝脏DNA的甲基化，确定了大鼠和小鼠同时口服[14C]二甲胺和亚硝酸钾后胃中N-亚硝基二甲胺（NDMA）的形成程度。给予约1mg盐酸二甲胺/千克体重和50mg亚硝酸钾/千克体重的剂量时，平均有0.8%的胺被亚硝化。大鼠个体波动范围为0.2%至1.3%，小鼠为0.2%至1.9%。同时给予50mg抗坏血酸钠（维生素C）/千克体重可使亚硝化作用抑制约80%，而50mg醋酸生育酚（维生素E）/千克体重可使亚硝化作用降低约一半。假设大鼠和人类体内亚硝化作用的动力学和条件相似，将饮食中二甲胺和亚硝酸盐在体内形成NDMA的情况与估计的人类对预先形成的NDMA的摄入量进行比较后发现，人类胃中NDMA的体内形成可能微不足道。
