Fetal Velocimetry & Amino Acid Transport in Pregnancy

胎儿测速

• 批准号: 6750734
• 负责人: FREDERICK C BATTAGLIA
• 金额: $ 34.56万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-20 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6750734
• 关键词: aminoacid transport; blood chemistry; clearance rate; clinical research; galactose; human pregnant subject; human subject; inositol; liver circulation; liver function; mannose; mother /embryo /fetus nutrition; newborn human (0-6 weeks); nutrient bioavailability; nutrition related tag; placental transfer; pregnancy circulation; prenatal growth disorder; stable isotope; ultrasound blood flow measurement; umbilical cord

DESCRIPTION (provided by applicant): The studies outlined are directed at nutrient transport and its relationship to blood flow in pregnancies complicated by intrauterine growth retardation (IUGR). The transport of the 9 essential amino acids across the placenta will be studied using stable isotopes and determining the fetal/maternal enrichments and tracer concentration ratios in normal and IUGR pregnancies. IUGR pregnancies are classified by clinical severity based upon velocimetry findings and FHR data. These data on amino acid transport will be analyzed for the impact of variations in umbilical blood flow directly measured with power Doppler techniques. This will establish whether delivery of amino acids to the fetus in IUGR pregnancies is impacted by a reduction in umbilical blood flow and whether this relationship is nonlinear. The non-glucose carbohydrates including the polyols will be measured in normal and IUGR pregnancies. Specific attention is given to D-mannose and myoinositol which are studied with stable isotopes of each sugar and of D-glucose infused into the maternal circulation till steady state enrichments are established. At that time, the fetal/maternal enrichment ratios for both myoinositol and D-mannose are determined. The glucose carbon incorporation into both mannose and myoinositol will be compared in normal and IUGR pregnancies. The studies will establish which, if any, of these carbohydrates relies upon transplacental transport vs. synthesis within the fetal or placental tissues. It will determine if the transplacental gradient for some carbohydrates and polyols are increased in IUGR pregnancies as the gradient is for glucose. Finally, the impact upon the IUGR newborn of an enormous reduction in hepatic blood flow in utero will be assessed. The newborns with a marked reduction in hepatic blood flow can be detected in utero from the reduction in umbilical blood flow coupled with an increase in the ductus venosus shunt. Evidence of hepatocellular damage will be sought at delivery by analysis of cord blood for specific clotting factors and hepatic enzymes. In addition, functional disturbance in neonatal liver function will be assessed by D-galactose plasmal clearance in the newborn after a milk feeding. These studies will establish important links between blood flow changes in the fetus and nutrient delivery to the fetus.

描述（由申请人提供）：概述的研究针对妊娠期并发宫内生长迟缓（IUGR）时的营养转运及其与血流的关系。将使用稳定同位素研究 9 种必需氨基酸穿过胎盘的转运，并确定正常和 IUGR 妊娠中胎儿/母体的富集和示踪剂浓度比。 IUGR 妊娠根据测速结果和胎心率数据按临床严重程度进行分类。将分析这些关于氨基酸转运的数据，以分析使用功率多普勒技术直接测量的脐血流量变化的影响。这将确定 IUGR 妊娠中向胎儿输送氨基酸是否受到脐血流量减少的影响，以及这种关系是否是非线性的。将在正常妊娠和 IUGR 妊娠中测量包括多元醇在内的非葡萄糖碳水化合物。特别关注 D-甘露糖和肌醇，用每种糖和 D-葡萄糖的稳定同位素注入母体循环中进行研究，直至建立稳态富集。此时，确定胎儿/母体肌醇和 D-甘露糖的富集比。将比较正常妊娠和 IUGR 妊娠中葡萄糖碳掺入甘露糖和肌醇的情况。这些研究将确定这些碳水化合物中哪些（如果有的话）依赖于胎盘转运与胎儿或胎盘组织内的合成。它将确定 IUGR 妊娠中某些碳水化合物和多元醇的经胎盘梯度是否会像葡萄糖的梯度一样增加。最后，将评估子宫内肝血流量大幅减少对 IUGR 新生儿的影响。通过脐血流量的减少以及静脉导管分流的增加，可以在子宫内检测到肝血流量显着减少的新生儿。分娩时将通过分析脐带血中的特定凝血因子和肝酶来寻找肝细胞损伤的证据。此外，新生儿肝功能的功能障碍将通过母乳喂养后新生儿 D-半乳糖血浆清除率进行评估。这些研究将建立胎儿血流变化和胎儿营养输送之间的重要联系。