TRANSPORT MECHANISMS OF MAMMALIAN BLASTOCYSTS

拟议研究的总体目标是澄清 肿胀的生理转运机制 胚泡是着床的重要前提。研究将会是 在最大(兔子)和最小(鼠标)展开类型的 胚泡。有五个具体目标，都是针对 离子和水运输的分子机制研究 穿过滋养外胚层上皮。具体目标1-3涉及 电压钳/灌流系统的研制及钾离子的研究 通量、Na/K-ATPase分布和活性的测定 滋养外胚层内的泵。具体目标四个方面的研究 旨在确定外源性病原体，特别是那些可能 在母体中出现，会影响上皮细胞的运输。 将特别强调阐明生理学上的 多种离子开/关信号的调控机制 运输系统。第五，生理上的细胞内浓度 重要的离子，如Na+，K+，Cl+，磷酸盐和钙将用 电子探针微量分析。这些研究将有助于我们的 对显影离子的动力学和生化性质的认识 植入前哺乳动物胚胎的运输系统，并增加我们的 对早孕生理学的理解。

The overall objective of the proposed research is to elucidate the physiological transport mechanisms involved in the swelling of the blastocyst, an important prerequisite for implantation. Studies will be done on maximally (rabbit) and minimaly (mouse) expanding types of blastocyst. There are five specific aims, all directed towards investigating the molecular mechanisms involved in ion and water transport across the trophectodermal epithelium. Specific aims 1-3 involve the development of a voltage clamp/perfusion system, the study of potassium ion fluxes, and measurement of the distribution and activity of Na/K-ATPase pumps within the trophectoderm. Specific aim four concerns studies designed to determine whether exogenous agents, particularly those likely to arise in the mother, can affect transport across the epithelium. Particular emphasis will be placed upon elucidating the physiological control mechanisms involved in the on/off signaling of various ion transport systems. Fifth intracellular concentrations of physiologically important ions like Na+, K+, Cl+, phosphate, and calcium will be made using electron probe microanalysis. These studies will contribute to our knowledge of the kinetic and biochemical properties of developing ion transport systems in preimplantation mammalian embryos, and increase our comprehension of the physiology of early pregnancy.