UMBILICAL VENOUS BLOOD FLOW & AMINOACID TRANSPORT & METABOLISM

该项目的具体目标包括正常的临床研究。 妊娠和妊娠合并胎儿生长受限。这个 氨基酸胎盘体内转运和代谢的随访研究 观察到胎儿的氨基酸浓度显著地 胎儿生长减少限制了怀孕。一项非稳态研究 利用稳定的必需和非必需氨基酸同分异构体 计划进行脐带穿刺术的孕妇检查体内转运 不同氨基酸基团的比率；a.)定义不同之处 其体内转运的相对速率和b。以测试氨基 与正常妊娠相比，FGR孕妇的胃酸转运减少 所有氨基酸或特定亚群的妊娠。稳态稳定 同位素方法学也被用来测试胎儿和母亲 注入的氨基酸稳定异构体的富集率 FGR妊娠的母体循环较低，反映了下降 运输和蛋白质周转增加。母性关系 正常和FGR妊娠的脐血摄取浓度也是 利用脐动静脉差值数据进行调查 是在剖腹产时确定的。最后，直接的作用 脐静脉血流量与动脉血流量的比较 速度测量仪测量和胎儿血液化学检查周围 胎儿宫内发育迟缓临床严重程度分类框架。

The specific aims of this project involve clinical studies in normal pregnancies and pregnancies complicated by fetal growth restriction. The study of in vivo amino acid placental transport and metabolism follow-up observations that fetal amino acid concentrations are significantly reduced in fetal growth restricted pregnancies. A non steady state study utilizing stable isoptomers of essential and nonessential amino acids in pregnant women scheduled for cordocentesis examines in vivo transport rates for different groups of amino acids; a.) to define differences in their relative rates of in vivo transport and b.) to test whether amino acid transport is reduced in FGR pregnancies compared to normal pregnancies for all amino acids or a specific subset. Steady state stable isotope methodology is also used to test whether the fetal maternal enrichment ratios for stable isoptomers of amino acids infused into the maternal circulation is lower in FGR pregnancies reflecting decreased transport and increased protein turnover. The relationship of maternal concentration to umbilical uptake for normal and FGR pregnancies is also investigated utilizing data on umbilical arterial venous differences determined at the time of cesarean section. Finally the role of direct measurements of umbilical venous blood flow compared to arterial velocemetry measurements and fetal blood chemistry is examined around the framework of the classification of clinical severity in FGR pregnancies.