N-nitroso-N-methylurea-induced mammary carcinogenesis: effect of pregnancy on preneoplastic cells.
N-nitroso-N-methylurea-induced mammary carcinogenesis: effect of pregnancy on preneoplastic cells.
复制标题
DOI：
10.1093/jnci/71.3.625
复制
发表时间：
1983-09
期刊：
影响因子：
--
通讯作者：
C. Grubbs;D. L. Hill;K. McDonough;J. Peckham
中科院分区：
文献类型：
--
作者：
C. Grubbs;D. L. Hill;K. McDonough;J. Peckham
在雌性远交Sprague-Dawley大鼠中测定了妊娠和哺乳对N-亚硝基-N-甲基脲（NMU）诱发乳腺癌的影响。动物在50日龄时接受5 mg NMU/100 g体重，并分为以下组：未交配、妊娠（从NMU给药后10天开始）、妊娠和哺乳（从NMU给药后10天开始）以及妊娠和哺乳（从NMU给药后82天开始）。在经历早期妊娠的大鼠中，第一个可触知的癌症出现的时间较短。然而，在妊娠后或妊娠和哺乳完成后的大鼠中检测到很少的癌症，并且在研究结束时在这些动物中观察到未交配大鼠的癌症发病率降低。由于NMU是一种半衰期短的直接作用致癌物，因此妊娠对致癌物代谢或结合没有影响。妊娠前存在的癌前细胞似乎已经被与妊娠相关的激素改变（例如它们的潜伏期增加）或破坏。
The effect of pregnancy and lactation on mammary cancers induced with N-nitroso-N-methylurea (NMU) was determined in female outbred Sprague-Dawley rats. The animals received 5 mg NMU/100 g body weight at 50 days of age and were divided into the following groups: virgin, pregnancy (beginning 10 days after NMU administration), pregnancy and lactation (beginning 10 days after NMU), and pregnancy and lactation (beginning 82 days after NMU). The time of appearance of the first palpable cancers was shorter in rats undergoing an early pregnancy. Few cancers, however, were detected from rats after pregnancy or pregnancy and lactation was completed, and a decrease in cancer incidence from virgin rats was observed in these animals at termination of the study. Since NMU is a direct-acting carcinogen with a short half-life, no effect of pregnancy on carcinogen metabolism or binding could have occurred. Preneoplastic cells present before pregnancy appeared to have been either altered (such that their latent period was increased) or destroyed by the hormones associated with pregnancy.