摘要
What summarized in this paper is the progress in recent years' in the causdive mechanism on study of developmental toxicants as chemical teratogenesis in three aspects.(1) It is about the phenomena and the possible reason of chemical teratogenesis in the preimplantation period. These research results are contrary to the past traditional concepts. (2) Due to using much more molecular biology methods, it can be observed more dead foetus phenomena before birth, which cannot be done previously and are of great value for reference. (3) When analyzing the genetic reason of chemical abnormal, a new research idea may be showed, i.e. the developmental abnormal due to chemical teratogenesis is induced with association of more relative genes and their expression abnormal. 13 references are involved in.
阐明化学物致畸等发育毒性的作用机理，对建立人类致畸物或发育毒物的鉴定手段和防治工作都有重要意义。近年来随着发育基因或发育调控基因的发现和功能的阐明，发育异常的机理研究也取得一些突破。本文简要概述了几个主要进展。长期以来，一直认为哺乳动物发育的着床前胚胎阶段是诱发实验性先天畸形的不敏感期。因此，现行化学物的致畸性测试均规定在胚胎着床后的器官形成期给予受试物。然而，近年来的研究发现，在着床前期给予某些化学物可导致胎儿畸形、生长发育迟缓和出生后行为功能异常等发育毒性，这对传统的概念是一个大的冲击，即胚胎早期可能也是致畸等毒性的敏感期。如果确实如此，将意味着现行化学物致畸性测试方案需修改，而且以往已进行过致畸性安全性评价的化学物就存在潜在的危险性。对于早期胚胎损伤所致发育异常的机理现有两种假设，一种是根据甲基亚硝基脲的研究认为，胚泡阶段发生了微小的非致死性突变；另一种是基于环氧乙烷等化学物对受精卵的损伤，认为原发性损害是非遗传性的，是由于干扰早期胚胎基固表达的原定程序。据估计，人类胚胎至少有６０％在出生前死亡，其中大多发生在妊娠早期，只有约１５％在着床后死亡。但长期以来对出生前死亡的原因所知甚少，仅知道流产儿中染色?
