REGULATION OF AMNIOTIC FLUID VOLUME

拟议研究的长期目标是了解 羊水调节的具体机制 正常和异常情况下的音量。这些研究 将在长期留置尿管的怀孕绵羊身上进行 在怀孕的最后50天里。先进的方法将是 用于测量羊水量、胎儿尿量 进入羊膜腔，胎儿吞下羊水。 此外，流体和电解液的运动 将在多种条件下探索胎儿的胎膜。 第一项研究旨在确定在多大程度上 羊水量的每日变化与变化有关 胎儿尿流率和吞咽情况。以确定是否 胎儿水合的变化导致羊水的变化 体积，生理盐水将被静脉注入 一段时间内的胎儿。羊水和尿囊液量 将通过注入等渗液来单独探索调节 在一段时间内进入这些空间，并将 相关体积和成分随着输液的变化而变化， 尿流率和吞咽率。的相对贡献率 液体和液体的吞噬和跨膜运动 电解质对羊水容量的调节将是 通过将羊水量变化与尿量相关来确定 食道和气管结扎后的血流。有……的存在 胎盘在调节羊水量中的作用 将胎儿尿液和羊水测定一段时间 天数，并将净体积和电解质损失与 胎盘渗透压和电解质浓度的变化 渐变。最后，个体荷尔蒙对 调节将通过注入精氨酸加压素来确定， 催乳素、皮质醇或血管紧张素II进入羊水 将音量和成分的相关变化与 羊水中的激素浓度。总体而言， 拟议的研究很重要，因为它们将极大地扩展 我们对羊水量调节的理解。 因为羊水量的异常与 如果胎儿死亡或围产儿结局不佳，拟议的研究可能 从而降低胎儿和新生儿的发病率和死亡率。

The long-term objective of the proposed studies is to understand the detail mechanisms involved in the regulation of amniotic fluid volume under normal as well as abnormal conditions. The studies will be conducted in chronically catheterized pregnant sheep during the last 50 days of gestation. Advanced methods will be used for measuring amniotic fluid volume, fetal urinary output into the amniotic space, and fetal swallowing of amniotic fluid. In addition, the movement of fluid and electrolytes across the fetal membranes will be explored under a number of conditions. The first study is designed to determine to what extent the large daily variations in amniotic fluid volume are related to variations in fetal urine flow rate and swallowing. To determine whether changes in fetal hydration lead to alterations in amniotic fluid volume, physiological saline will be infused intravenously into the fetus over a period of days. Amniotic and allantoic fluid volume regulation will be explored separately by infusing isotonic fluids into these spaces over a period of days and correlating the associated volume and composition changes with the infusion, urine flow, and swallowing rates. The relative contribution of swallowing and transmembrane movements of fluid and electrolytes to amniotic fluid volume regulation will be determined by correlating the amniotic volume changes with urine flow following esophageal and tracheal ligation. The exent to which the placenta is involved in regulating amniotic fluid volume will be determined fetal urine and amniotic fluid for a period of days and relating the net volume and electrolyte loss to the changes in transplacental osmotic and electrolyte concentration gradients. finally, the contribution of individual hormones to regulation will be determined by infusing arginine vasopressin, prolactin, cortisol, or angiotensin II into the amniotic fluid and relating the associated changes in volume and composition to the hormone concentrations in amniotic fluid. Collectively, the proposed studies are important because they will greatly expand our understanding of the regulation of amniotic fluid volume. Because aberrations in amniotic fluid volume are associated with fetal death or poor perinatal outcome, the proposed studies may lead to a decreased fetal and neonatal morbidity and mortality.