REPRODUCTIVE TOXICOLOGY OF ENVIRONMENTAL MUTAGENS

一个研究化学品暴露对发展中国家的危险的模型系统 植入前胚胎已经发育。 短期和长期 可以研究这种暴露的影响。 传统上，人们认为 妊娠雌性在着床前暴露于有毒物质 这段时间没有结果，因为化合物不能到达 或者是因为胚胎被暴露在阳光下而死亡。 我们研究了 已知会导致出生缺陷或肿瘤形成的化学物质的影响。 我们在体外暴露了植入前胚胎（囊胚）， 证明放射性标记前体的掺入显著减少 RNA，DNA和蛋白质在可行的，处理过的胚胎。 我们知道从具体的 标记实验表明该化合物被小鼠胚泡吸收。 我们 我希望不久就能将暴露的胚胎放入假孕的福斯特的子宫里 妈妈们 通过这种胚胎移植实验， 确定暴露于环境致癌物对着床的影响 出生率、出生率以及这种接触与出生缺陷的关系。 这些 技术很容易适用于其他环境相关的化合物， 为了确定早期胚胎暴露的潜在风险， 当怀孕的母亲不知道她的时候， 怀孕 子宫内膜在激活致癌物质中的作用将是 利用子宫内膜细胞培养系统进行研究。

A model system to study the risk from chemical exposure to developing preimplantation embryos has been developed. Both short-term and long-term effects of such exposure can be studied. Traditionally, it was thought that exposure of pregnant females to toxic substances during the preimplantation period is without consequence either because the compound cannot reach the cleaving egg or because the embryo is killed by the exposure. We have looked at the effects of chemicals known to cause either birth defects or tumor formation. We have exposed preimplantation embryos (blastocysts) in vitro and have demonstrated a significant decrease in incorporation of radiolabeled precursors of RNA, DNA, and protein in viable, treated embryos. We know from specific labeling experiments that this compound is taken up by the mouse blastocyst. We hope soon to place exposed embryos in the uteri of pseudopregnant foster mothers. With such embryo transfer experiments, it will be possible to determine the effects of exposure to environmental carcinogens on implantation rate, birth rates and the relation of such exposure to birth defects. These techniques are easily applicable to other environmentally relevant compounds, in order to determine potential risk of exposure for the embryo in the early periods of development at a time when the pregnant mother is unaware of her pregnancy. The role of the endometrium in activating the carcinogens will be investigated utilizing endometrial cell-culture systems.