ACUTE EFFECTS OF PARTIAL COMPRESSION OF DUCTUS-ARTERIOSUS ON FETAL PULMONARY CIRCULATION
ACUTE EFFECTS OF PARTIAL COMPRESSION OF DUCTUS-ARTERIOSUS ON FETAL PULMONARY CIRCULATION
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DOI：
10.1152/ajpheart.1989.257.2.h626
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发表时间：
1989-08-01
影响因子：
--
通讯作者：
ACCURSO, FJ
中科院分区：
文献类型：
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作者：
ABMAN, SH;ACCURSO, FJ
为了确定肺动脉压力和流量增加对胎儿肺循环的急性影响，我们研究了22只长期准备的妊娠晚期胎儿羔羊的肺血流和血管反应性对动脉导管部分压迫的反应。在动脉导管周围松散放置充气式封堵器进行压缩。导管部分受压迅速使平均肺动脉压从45 .+-升高。1 ~ 60 +-。1毫米汞柱(平均+-。SE)和左肺动脉血流量从65 +-。6至151 .+-。11ml /min, 30min （P < 0.001； 12只动物）。尽管保持肺动脉压不变，但肺血流量稳步下降，并在2小时内与基线值无差异。肺血管阻力在部分压迫的前30分钟内开始下降，但随后稳步上升，并在释放封堵器后至少30分钟内保持高于基线值的水平（P < 0.001）。使用环氧合酶抑制剂甲氯芬酯治疗后，肺血管阻力在压迫前30分钟的下降趋势被减弱（P < 0.001； 6只动物）。快速增加的管道压缩表明压力-流量关系的斜率从3.30 .+-减小。0.27（对照）至1.59。0.21 ml .cntdot。最低为1 .cntdot。压缩后的mmHg-1 （P < 0.001； 12只动物）。胎儿PO2小幅度升高的血管舒张反应在压缩后明显减弱（P < 0.001）。我们的结论是，动脉导管部分受压的血流动力学反应是时间依赖性的，肺血流的初始增加部分是由局部释放血管舒张环氧化酶产物介导的。急性高血压后肺血管阻力升高、压力-流量关系改变以及血管舒张反应减弱的机制尚不清楚。
To determine the acute effects of increased pulmonary artery pressure and flow on the fetal pulmonary circulation, we studied the response of pulmonary blood flow and vascular reactivity to partial compression of the ductus arteriosus in 22 chronically prepared late-gestation fetal lambs. An inflatable occluder was placed loosely around the ductus arteriosus for compression. Partial compression of the ductus rapidly increased mean pulmonary artery pressure from 45 .+-. 1 to 60 .+-. 1 mmHg (mean .+-. SE) and left pulmonary artery blood flow from 65 .+-. 6 to 151 .+-. 11 ml/min at 30 min (P < 0.001; 12 animals). Despite keeping pulmonary artery pressure constant, pulmonary blood flow steadily declined and by 2 h was not different from base-line values. Pulmonary vascular resistance initially fell during the first 30 min of partial compression but then steadily increased and remained elevated above base-line values for at least 30 min after the release of the occluder (P < 0.001). The decline of pulmonary vascular resistance during the first 30 min of compression was blunted after treatment with the cyclooxygenase inhibitor, meclofenamate(P < 0.001; 6 animals). Rapid incremental ductus compressions demonstrated a decrease in the slope of the pressure-flow relationship from 3.30 .+-. 0.27 (control) to 1.59 .+-. 0.21 ml .cntdot. min-1 .cntdot. mmHg-1 during the postcompression period (P < 0.001; 12 animals). The vasodilation response to small increases of fetal PO2 was markedly blunted during the postcompression period (P < 0.001). We conclude that the hemodynamic response to partial compression of the ductus arteriosus is time dependent, with the initial rise of pulmonary blood flow partially mediated by the local release of a vasodilating cyclooxygenase product. Mechanisms contributing to subsequent elevations of pulmonary vascular resistance, changes in the pressure-flow relationship, and attenuation of the vasodilation response after acute hypertension are not yet known.