TRANSPORT MECHANISMS OF MAMMALIAN BLASTOCYSTS

拟议研究的总体目标是阐明 参与肿胀的生理运输机制 胚泡是着床的重要先决条件。 研究将 在最大（兔）和最小（小鼠）扩张类型上进行， 胚泡 有五个具体目标， 研究离子和水运输的分子机制 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，钾离子的研究 Na/K-ATP酶的分布和活性测定 滋养外胚层内的泵。 具体目标四关注研究 旨在确定是否有外源性因子，特别是那些可能 在母体中产生，可以影响上皮细胞的运输。 特别强调将放在阐明生理 控制机制涉及各种离子的开/关信号 运输系统。 第五种生理性细胞内浓度 重要的离子，如Na+，K+，Cl+，磷酸盐和钙将使用 电子探针微量分析 这些研究将有助于我们 了解发展中离子的动力学和生物化学性质 运输系统在植入前哺乳动物胚胎，并增加我们的 了解怀孕早期的生理学。

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.