Ehrenkranz R A, Walker A M, Oakes G K, McLaughlin M K, Chez R A
Am J Obstet Gynecol. 1976 Oct 1;126(3):343-9. doi: 10.1016/0002-9378(76)90547-0.
The effect of ritodrine upon uterine artery blood flow (UtBF) and umbilical vein blood flow (UmBF) was investigated in near-term chronic sheep preparations. During intravenous ritodrine infusions to the ewe in sequential dose rates from 100 to 800 mug per minute, UtBF fell progressively to 43 per cent below control levels and mean maternal arterial pressure (MMAP) declined 20 per cent. During constant infusions of 100, 400, or 800 mug per minute of ritodrine to the ewe for 120 minutes,, UtBF decreased 10, 37, and 31 per cent, respectively, and MMAP decreased 6, 20 and 25 per cent respectively. Dose-related maternal tachycardia and hyperglycemia occurred. There were no significant changes in UmBF, mean fetal arterial pressure, or fetal heart rate. During all infusions, maternal and fetal arterial pH, PCO2, and PO2 remained within normal physiologic limits. Simultaneous infusion of ritodrine (400 mug per minute) and propranolol (100 mug per minute) blocked the maternal tachycardia, but decreases in UtBF, MMAP, and UmBF were observed. Ritodrine infusions to the fetus (25 mug per minute) resulted in fetal tachycardia and a variable increase in UmBF.
在接近足月的慢性绵羊实验准备中，研究了利托君对子宫动脉血流（UtBF）和脐静脉血流（UmBF）的影响。在以每分钟100至800微克的连续剂量率向母羊静脉输注利托君的过程中，UtBF逐渐下降至低于对照水平43%，母羊平均动脉压（MMAP）下降20%。在以每分钟100、400或800微克的剂量持续向母羊输注利托君120分钟的过程中，UtBF分别下降了10%、37%和31%，MMAP分别下降了6%、20%和25%。出现了与剂量相关的母羊心动过速和高血糖。UmBF、胎儿平均动脉压或胎儿心率没有显著变化。在所有输注过程中，母羊和胎儿的动脉pH值、PCO2和PO2均保持在正常生理范围内。同时输注利托君（每分钟400微克）和普萘洛尔（每分钟100微克）可阻断母羊心动过速，但观察到UtBF、MMAP和UmBF下降。向胎儿输注利托君（每分钟25微克）导致胎儿心动过速和UmBF的可变增加。
Zotero 插件