Stevens A D, Lumbers E R
School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia.
Am J Physiol. 1990 Nov;259(5 Pt 2):R1004-11. doi: 10.1152/ajpregu.1990.259.5.R1004.
Uterine blood flow (UBF) was reduced for 1 h by partially occluding the maternal aorta below the renal arteries in seven pregnant ewes (gestation age 126-134 days). Fetuses became hypoxic, acidemic, and hypercapnic. They developed hypertension (P less than 0.005) and a bradycardia (P less than 0.05). During restricted UBF, fetal hematocrit (Hct) rose (P less than 0.005) and blood volume fell in five of seven fetuses. After release of constriction, fetal Hct fell, and blood volume rose by 7.5 +/- 3.26% (P less than 0.05) relative to control. During reduced UBF, lung liquid and urine flow rates fell (P less than 0.025 and P less than 0.05, respectively). After the occluder was released, Na excretion (which did not fall significantly during reduced UBF) increased (P less than 0.05), and fractional reabsorption of Na fell (P less than 0.05). Changes in fetal blood volume (FBV) were directly related to changes in maternal lower body flow (r = 0.47, P = 0.01, n = 33), and changes in fetal Hct were inversely related to maternal flow (r = -0.635, P = 0.001). Fetal urinary Na excretion per kilogram body weight was directly related to FBV per kilogram (r = 0.44, P = 0.005, n = 40), whereas fractional reabsorption of Na was inversely related to FBV per kilogram body wt (r = 0.48, P less than 0.002, n = 39). It is concluded that reductions in UBF cause fetal hypoxemia and acidemia, which lead to changes in fetal cardiovascular function and in FBV.(ABSTRACT TRUNCATED AT 250 WORDS)
通过部分阻断7只妊娠母羊（妊娠年龄126 - 134天）肾动脉下方的母体主动脉，使子宫血流量（UBF）减少1小时。胎儿出现缺氧、酸血症和高碳酸血症。他们出现高血压（P < 0.005）和心动过缓（P < 0.05）。在子宫血流量受限期间，7只胎儿中有5只胎儿的血细胞比容（Hct）升高（P < 0.005），血容量下降。解除收缩后，胎儿Hct下降，血容量相对于对照组增加7.5±3.26%（P < 0.05）。在子宫血流量减少期间，肺液和尿流率下降（分别为P < 0.025和P < 0.05）。解除阻断后，钠排泄量（在子宫血流量减少期间未显著下降）增加（P < 0.05），钠的分数重吸收下降（P < 0.05）。胎儿血容量（FBV）的变化与母体下身血流量的变化直接相关（r = 0.47，P = 0.01，n = 33），胎儿Hct的变化与母体血流量呈负相关（r = -0.635，P = 0.001）。每千克体重胎儿尿钠排泄量与每千克FBV直接相关（r = 0.44，P = 0.005，n = 40），而钠的分数重吸收与每千克体重FBV呈负相关（r = 0.48，P < 0.002，n = 39）。得出结论：子宫血流量减少导致胎儿低氧血症和酸血症，进而导致胎儿心血管功能和FBV发生变化。（摘要截断于250字）
