PLACENTAL TRANSFER OF FLUORIDE

产前应用氟化物的临床和生物学效应 为了防止后代龋齿， 定义了 虽然许多研究探讨了母胎氟 胎儿硬组织中氟代谢和吸收的数据， 由于难以准确测定低浓度 血浆[F]，特别是在胎儿血浆中，其中水平极低。 此外，一个实用的，相关的和相对便宜的动物模型系统， 尚未成立。 我们改进了分析方法， 在低水平下准确测定F。 我们已经建立了 豚鼠作为控制实验的有用的相关模型系统。 该项目旨在扩展我们对参数的研究， 机制有关胎盘转移氟化物，使用几内亚 猪作为模型。 拟议的工作是我们的逻辑延伸。 以前的研究，特别是实验结果 在我们目前资助的项目赠款（赠款）的支持下进行 期间：1986年8月1日至1989年7月31日）。 母性的某些基本参数- 胎儿氟代谢已建立。 我们的数据提供了 数学关系的假设基础 母体血浆[F]、胎儿血浆[F]和釉质血浆[F]。 这 假设应该得到检验。 产前氟暴露对胎儿生长发育的影响 生后牙釉质对氟的吸收需要进一步研究。 而且， 胎盘转移F和从胎儿血浆中清除F的机制可以 现在被研究。 该项目包括三个具体目标： (1)为了验证胎儿血浆和发育中的牙釉质中[F] 与母体血浆具有可定义的数学关系[F]， 长期氟暴露的变化发生在妊娠期。 的关系 母体剂量和母体血浆[F]之间的差异也将是 确立了习 (2)探讨产前氟营养状况对胎儿氟代谢的影响， 在出生后发育中的釉质中的吸收。 (3)为了探索 参与F的胎盘转移和胎儿的清除 等离子体

The clinical and biological effects of prenatal administration of fluorides in an effort to prevent dental caries in the offspring are incompletely defined. Although numerous studies have explored maternal-fetal fluoride metabolism and uptake of fluoride in fetal hard tissues, the data were of limited value because of difficulties in accurately assaying for the low plasma [F], especially in fetal plasma where levels are extremely low. Also, a practical, relevant and relatively inexpensive animal model system had not been established. We have refined the analytical method to provide accurate assay of F at the low levels involved. And, we have established the guinea pig as useful, relevant model system for controlled experiments. This project is designed to extend our studies of the parameters and mechanisms concerning the placental transfer of fluorides, using the guinea pig as the model system. The proposed work is a logical extension of our previous studies, especially the findings resulting from experiments conducted with the support of our currently funded project grant (grant period: 8/1/86-7/31/89). Certain of the basic parameters of maternal- fetal fluoride metabolism have been established. Our data provide the basis for a hypothesis concerning the mathematical relationship between maternal plasma [F], fetal plasma [F], and enamel plasma [F]. This hypothesis should be tested. The effects of prenatal fluoride exposure on F uptake in enamel postnatally need to be explored. And, the basic mechanisms in placental transfer of F and F clearance from fetal plasma can now be studied. The project includes three Specific Aims: (1) To test the hypothesis that [F] in fetal plasma and developing enamel bear definable mathematical relationships to maternal plasma [F] when variations in chronic F exposure occur during gestation. The relationship between variations in maternal dose and maternal plasma [F] also will be established. (2) To determine the effect of prenatal fluoride status on F uptake in developing enamel postnatally. (3) To explore the mechanisms involved in the placental transfer of F and clearance from the fetal plasma.