Rice J M
Environ Health Perspect. 1979 Apr;29:23-27. doi: 10.1289/ehp.792923.
Experiments in rodents indicate that during the post-embryonic period of prenatal development, the fetus is more sensitive than the adult to certain carcinogens, by several decimal orders of magnitude. Most such agents are direct-acting and independent of metabolism. To other substances, often those which require enzyme-mediated metabolic conversion to a chemically reactive derivative in order to effect carcinogenesis, the fetus may be less vulnerable than the adult. The neonate is also more susceptible than adults to some carcinogens, and may be more susceptible than the fetus to certain agents. Both rodent and primate studies indicate that gravid females are also at elevated risk for carcinogenesis, in part because of the presence in the placenta of trophoblastic tissue which may become malignant. The contributions of rapid growth rate, changing metabolic competence, and tissue differentiation to elevated perinatal susceptibility to carcinogens in rodents and primates are discussed, together with the implications of these findings for human beings subjected to industrial or environmental exposures to such chemicals.
啮齿动物实验表明，在产前发育的胚胎后期，胎儿对某些致癌物的敏感性比成年动物高几个数量级。大多数这类致癌物是直接作用的，且与代谢无关。对于其他物质，通常是那些需要酶介导的代谢转化为化学反应性衍生物才能引发致癌作用的物质，胎儿可能比成年动物更不易受到影响。新生儿对某些致癌物也比成年人更敏感，并且对某些物质可能比胎儿更敏感。啮齿动物和灵长类动物的研究均表明，妊娠雌性动物发生癌变的风险也会升高，部分原因是胎盘存在可能恶变的滋养层组织。本文讨论了啮齿动物和灵长类动物快速生长速度、代谢能力变化和组织分化对围产期致癌物易感性升高的影响，以及这些发现对接触此类化学物质的工业或环境暴露人群的意义。
