MOLECULAR SIZE SELECTIVITY OF IMMATURE PLACENTA

我们的长期目标是获得有关 血液病动物未成熟胎盘通透性的研究 胎盘。人们的期望是，对未成熟胎盘的研究结果可以 被推断为人类早期胎盘，就像对成熟的结果一样 血绒毛胎盘可以推断为成熟的人类胎盘。 需要检验的第一个假设是，未成熟的胎盘 进化经历了改变渗透率和改变分子的阶段 选择性。第二个假设是 不同类型的血绒毛膜胎盘与月经周期密切相关 概念发展，可能比 组织结构。 具体目标是确定早期的渗透性 胎盘到亲水性、代谢惰性、带电和不带电 分子半径从0.2纳米到1.22纳米的探针。胎儿的胎盘 0.3、0.4、0.5、0.6和0.7胎龄将在几内亚进行研究 猪、兔子和老鼠。人血单膜胎盘的结构 与豚鼠胎盘密切相关。然而，它的分子 大小选择性更紧密地反映在分叉胎盘上。 兔胎盘和大鼠胎盘的血丝 豚鼠胎盘。出于这些原因，所有三种血液生化物种 将会被研究。 管理扩散交换的规则适用于所有材料 穿过胎盘屏障。正因为如此，研究 扩散转移提供了更多材料的信息 成本高于对载体中介转移的研究。对中国传统文化的研究 早期胎盘的通透性有助于预测暴露 早期人类胚胎对治疗性外源物质的水平 抗病毒/抗艾滋病毒药物和致畸剂，因为初步数据 表明它的渗透性远远低于成熟的同类产品。

The long-term objective is to obtain quantitative information on the permeability of the immature placenta in animals with hemochorial placentas. The expectation is that the results on immature placentas can be extrapolated to the early human placenta, like the results on mature hemochorial placentas could be extrapolated to the mature human placenta. The first hypothesis to be tested is that the immature placenta evolves through stages of changing permeability and changing molecular selectivity. The second hypothesis is that the permselectivities of the various types of hemochorial placentas are strongly related to stage of conceptual development, possibly more so than to differences in histological structure. Specific aims are to determine the permeability of the early placenta to hydrophilic, metabolically inert, charged and non-charged probes with molecular radii from 0.2 to 1.22 nanometers. Placentas of 0.3, 0.4, 0.5, 0.6, and 0.7 gestational age will be studied in the guinea pig, rabbit and rat. The hemomonochorial human placenta is structurally closely related to the guinea pig placenta. Nevertheless, its molecular size selectivity is more closely mirrored in the hemodichorial placenta of the rabbit and the hemotrichorial placenta of the rat than in the placenta of the guinea pig. For these reasons all 3 hemochorial species will be studied. The rules that govern diffusional exchange apply to all materials traversing the placental barrier. For this reason, the study of diffusional transfer provides information on more materials at lesser cost than the study of carrier mediated transfers. The study of the permeability of the early placenta will help to predict the exposure levels of the early human embryo to therapeutic xenobiotics such as antiviral/anti HIV agents and teratogens because preliminary data indicate that it is far less permeable than its mature counterpart.