UMBILICAL-CORD OCCLUSION STIMULATES BREATHING INDEPENDENT OF BLOOD-GASES AND PH
UMBILICAL-CORD OCCLUSION STIMULATES BREATHING INDEPENDENT OF BLOOD-GASES AND PH
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DOI：
10.1152/jappl.1991.70.4.1796
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发表时间：
1991-04-01
影响因子：
3.3
通讯作者：
OLSON, DM
中科院分区：
文献类型：
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作者：
ADAMSON, SL;KUIPERS, IM;OLSON, DM
通过使用 16 只接近足月的未麻醉胎羊，研究了脐带闭塞在出生时呼吸启动中的作用。采用高频振荡人工通气来控制胎儿动脉血气张力。基线时，PCO2 维持在对照胎儿值，PO2 升高至 25 至 50 Torr 之间。在第一项针对 6 个完整胎儿和 4 个迷走神经切断胎儿的研究中，动脉 PCO2 和 PO2 在两个 30 分钟的脐带闭塞期间保持恒定。然而，当脐带被阻断时，平均胎儿呼吸频率显着增加。在对六个完整胎儿的第二项研究中，通过在通气气体中添加二氧化碳来施加高碳酸血症（68 托）。当脐带被闭塞时，高碳酸血症对呼吸的刺激（速率、发生率和幅度）明显大于单独高碳酸血症的反应。脐带闭塞期间，血浆前列腺素E2浓度显着下降。结果表明，脐带闭塞可能通过导致胎盘产生的呼吸抑制剂（例如前列腺素 E2）从循环中去除来刺激呼吸。
The role of umbilical cord occlusion in the initiation of breathing at birth was investigated by use of 16 unanesthetized fetal sheep near full term. Artificial ventilation with high-frequency oscillation was used to control fetal arterial blood gas tensions. At baseline, PCO2 was maintained at control fetal values and PO2 was elevated to between 25 and 50 Torr. In the first study on six intact and four vagotomized fetuses, arterial PCO2 and PO2 were maintained constant during two 30-min periods of umbilical cord occlusion. Nevertheless, the mean fetal breathing rate increased significantly when the umbilical cord was occluded. In the second study on six intact fetuses, hypercapnia (68 Torr) was imposed by adding CO2 to the ventilation gas. When the umbilical cord was occluded, there was a significantly greater stimulation of breathing (rate, incidence, and amplitude) in response to hypercapnia than in response to hypercapnia alone. During cord occlusion, plasma prostaglandin E2 concentration decreased significantly. Results indicate that cord occlusion stimulates breathing possibly by causing the removal of a placentally produced respiratory inhibitor such as prostaglandin E2 from the circulation.