Berman W, Goodlin R C, Heymann M A, Rudolph A M
Circ Res. 1976 Apr;38(4):262-6. doi: 10.1161/01.res.38.4.262.
We studied the relationship of fetal and maternal vascular pressures to umbilical and uterine blood flow in the unanesthetized ewe and in the sheep fetus in utero by placing electromagnetic flow transducers around both the common umbilical and uterine arteries. Reductions in umbilical arterial pressure or elevations in umbilical venous pressure decreased umbilical blood flow without affecting either the uterine arterial blood flow or other maternal cardiovascular variables which were studied. Elevations in uterine venous pressure or reductions in uterine arterial pressure decreased uterine arterial flow but these interventions had no effect on umbilical blood flow until fetal hypoxemia and bradycardia occurred. When the bradycardia of the fetal hypoxic response was inhibited by atropine, alterations in maternal vascular pressure had no effect on umbilical arterial flow. These data do not support the presence of a "sluice" or "waterfall" effect in the umbilical-placental circulation of the sheep fetus in utero.
我们通过在脐动脉和子宫动脉周围放置电磁流量传感器，研究了未麻醉母羊及其子宫内绵羊胎儿的胎儿和母体血管压力与脐血流和子宫血流之间的关系。脐动脉压降低或脐静脉压升高会减少脐血流，而不影响子宫动脉血流或所研究的其他母体心血管变量。子宫静脉压升高或子宫动脉压降低会减少子宫动脉血流，但这些干预措施在胎儿出现低氧血症和心动过缓之前对脐血流没有影响。当胎儿缺氧反应的心动过缓被阿托品抑制时，母体血管压力的改变对脐动脉血流没有影响。这些数据不支持子宫内绵羊胎儿的脐-胎盘循环中存在“水闸”或“瀑布”效应。
