Stevens A D, Lumbers E R
School of Physiology and Pharmacology, University of New South Wales, Kensington, Australia.
Can J Physiol Pharmacol. 1995 Feb;73(2):202-8. doi: 10.1139/y95-029.
To determine the effects on the fetus of high maternal levels of noradrenaline, experiments were carried out in 17 pregnant ewes (123-137 days gestation). Intravenous infusion of 40 mg/min of norepinephrine to the ewe for 1.5 h increased maternal arterial pressure and significantly decreased maternal placental blood flow (p < 0.05). Fetal arterial pressure did not change, but fetal arterial PO2 fell (p < 0.01) and PCO2 rose (p < 0.01). Fetal urine flow fell and osmolality rose (p < 0.01), fetal lung liquid flow and osmolar excretion fell (p < 0.01, p < 0.05, respectively), and the lung sodium:potassium ratio changed. These effects of high levels of maternal noradrenaline were transient, i.e., 2.5 h after the infusion of noradrenaline had finished, fetal urine flow and lung liquid flow had both returned to control values and fetal PCO2 was significantly depressed relative to control values (p < 0.01). It is concluded that high levels of maternal catecholamines reduce placental blood flow and cause small changes in fetal oxygenation. These changes are sufficient to transiently affect fetal water excretion and to reduce lung liquid flow.
为了确定母体高水平去甲肾上腺素对胎儿的影响，对17只怀孕母羊（妊娠123 - 137天）进行了实验。以40毫克/分钟的速度向母羊静脉输注去甲肾上腺素1.5小时，可使母体动脉血压升高，并显著降低母体胎盘血流量（p < 0.05）。胎儿动脉血压未发生变化，但胎儿动脉血氧分压下降（p < 0.01），二氧化碳分压升高（p < 0.01）。胎儿尿流量下降，渗透压升高（p < 0.01），胎儿肺液流量和渗透排泄量下降（分别为p < 0.01，p < 0.05），肺钠钾比发生变化。母体高水平去甲肾上腺素的这些影响是短暂的，即去甲肾上腺素输注结束2.5小时后，胎儿尿流量和肺液流量均恢复到对照值，且胎儿二氧化碳分压相对于对照值显著降低（p < 0.01）。得出的结论是，母体高水平儿茶酚胺会减少胎盘血流量，并导致胎儿氧合发生微小变化。这些变化足以短暂影响胎儿水排泄并减少肺液流量。
