Murthy A S, Baker J R, Smith E R, Zepp E
Int J Cancer. 1979 Feb;23(2):253-9. doi: 10.1002/ijc.2910230217.
In projected 485-day studies, Fischer 344 rats and C57BL/6 mice were fed 0.58% butylurea and 0.50% sodium nitrite mixed in the diet separately or in combination. The number and type of neoplasms were not significantly increased in either species receiving butylurea or sodium nitrite only. Feeding the two chemicals simultaneously induced neoplasms of the lung, Zymbal's gland, forestomach, intestine and hemopoietic tissues in rats, and malignant lymphomas in mice. The increased incidence of neoplasms in rats and mice fed butylurea and sodium nitrite in combination may result from in vivo formation of the carcinogen, N-butyl-N-nitrosourea.
在预计为期485天的研究中，将0.58%的丁基脲和0.50%的亚硝酸钠分别或混合添加到饲料中，喂食Fischer 344大鼠和C57BL/6小鼠。仅接受丁基脲或亚硝酸钠的任一物种中，肿瘤的数量和类型均未显著增加。同时喂食这两种化学物质会诱发大鼠的肺部、耳下腺、前胃、肠道和造血组织肿瘤，以及小鼠的恶性淋巴瘤。联合喂食丁基脲和亚硝酸钠的大鼠和小鼠肿瘤发生率增加，可能是由于体内致癌物N-丁基-N-亚硝基脲的形成。
