Hayashi T T
Obstet Gynecol Annu. 1977;6:11-22.
The preceding résumé of placental nucleic acid metabolism indicates considerable changes in RNA and DNA during the course of pregnancy in both human and animal experiments. The presence of an active protein-synthesizing apparatus closely allied with DNA and RNA metabolism has been observed in placental preparations; future studies should reveal even more direct relationships. The specific regulatory role of nucleic acids in normal and abnormal placental function is still unknown. In truth, such specific regulatory or control mechanisms are generally unproved among the entire mammalian (eukaryotype) system. Progress in learning about placental function and control may require more detailed information regarding RNA metabolism from molecular biology. The regulatory control of fetal or intrauterine growth as it relates to nucleic acids remains even more obscure. One of the major drawbacks in this study has been our inability to label fetal tissues adequately during the major portion of the pregnancy. The problem is made even more complex by the many factors involved in intrauterine growth, such as blood volume, uterine blood supply, oxygen flow and transfer, hormonal effects, and nutritional status, in addition to nucleic acids.
上述关于胎盘核酸代谢的概述表明，在人类和动物实验中，孕期RNA和DNA都有相当大的变化。在胎盘制剂中已观察到存在与DNA和RNA代谢密切相关的活跃蛋白质合成装置；未来的研究应揭示出更直接的关系。核酸在正常和异常胎盘功能中的具体调节作用仍然未知。事实上，在整个哺乳动物（真核型）系统中，这种具体的调节或控制机制通常尚未得到证实。了解胎盘功能和控制方面的进展可能需要从分子生物学获得更多关于RNA代谢的详细信息。与核酸相关的胎儿或子宫内生长的调节控制仍然更加模糊。这项研究的主要缺陷之一是，在孕期的大部分时间里，我们无法充分标记胎儿组织。除了核酸外，子宫内生长涉及的许多因素，如血容量、子宫血液供应、氧流量和转运、激素作用以及营养状况，使这个问题变得更加复杂。
