Morin F C
Department of Pediatrics, State University of New York, Buffalo 14214.
Pediatr Res. 1989 Mar;25(3):245-50. doi: 10.1203/00006450-198903000-00005.
We determined whether closing the ductus arteriosus of the fetal lamb several d before birth would cause persistent pulmonary hypertension after birth. Six experimental fetuses who had their ductus arteriosus ligated 3-17 d before delivery, three control fetuses who had sham ligation of the ductus arteriosus 14 d before delivery, and six control fetuses who had no prenatal surgery were delivered by cesarean section between 138 and 144 d of gestation. Each was instrumented to measure pulmonary and systemic arterial pressures and pulmonary blood flow. Each newborn lamb was ventilated with room air during the first 45 min after birth and then with decreasing amounts of inspired oxygen from 100 to 9%. Pulmonary arterial pressure decreased significantly when ventilation was begun in the control lambs but not in the lambs who had their ductus arteriosus ligated before delivery. Throughout the experiment, pulmonary arterial pressure and total pulmonary resistance were significantly higher, and pulmonary blood flow was significantly lower in the lambs who had their ductus arteriosus ligated before delivery. In two of them, pulmonary arterial pressure was greater than or equal to systemic arterial pressure, even during ventilation with 100% oxygen. This animal preparation provides a method of investigating persistent pulmonary hypertension in the newborn lamb and may provide insight into an etiology of the syndrome of persistent pulmonary hypertension of the newborn.
我们确定在出生前几天闭合胎羊的动脉导管是否会导致出生后持续性肺动脉高压。六只实验胎儿在分娩前3 - 17天结扎动脉导管，三只对照胎儿在分娩前14天接受动脉导管假结扎，六只未进行产前手术的对照胎儿在妊娠138至144天通过剖宫产分娩。每只胎儿都安装了测量肺动脉和体动脉压力以及肺血流量的仪器。每只新生羔羊在出生后的前45分钟用室内空气通气，然后吸入氧气量从100%逐渐减少到9%。对照羔羊开始通气时肺动脉压力显著下降，但在分娩前结扎动脉导管的羔羊中未出现这种情况。在整个实验过程中，分娩前结扎动脉导管的羔羊的肺动脉压力和总肺阻力显著更高，肺血流量显著更低。其中两只羔羊即使在吸入100%氧气通气时，肺动脉压力也大于或等于体动脉压力。这种动物模型提供了一种研究新生羔羊持续性肺动脉高压的方法，可能有助于深入了解新生儿持续性肺动脉高压综合征的病因。
