Ohara T, Ogata H, Tezuka F
Department of Pediatrics, Tohoku University School of Medicine, Sendai.
Tohoku J Exp Med. 1991 May;164(1):67-79. doi: 10.1620/tjem.164.67.
Exposure of the fetus to indomethacin and the resultant closure of the ductus arteriosus in utero has been suggested to be one possible cause of persistent pulmonary hypertension of the newborn (PPHN). We examined whether or not closing the ductus arteriosus of fetal lambs by the administration of in-domethacin to the fetus and ewe could produce the functional and structural changes of PPHN. Three treated and four non-treated lambs were delivered by cesarean section. Postnatal hemodynamics were studied in two of the treated lambs. Pulmonary arterial pressure gradually decreased after delivery and did not reveal features compatible with PPHN, while the blood gases remained within the physiological range. However, acute hypoxemia produced a re-elevation in pulmonary arterial pressure. Morphometric analysis showed the medial thickening of normally fully-muscularized pulmonary arteries, but there was no abnormal extension of fully-muscularized arteries to the intraacinar level in the treated lambs. In conclusion, we could not reproduce functional and structural changes of PPHN in newborn lambs by the administration of indomethacin in utero. However, our experimental animal model with excessive muscularization of the pulmonary vasculature appears to be useful for studying vasoconstriction in response to hypoxemia.
胎儿在子宫内接触吲哚美辛并导致动脉导管关闭，被认为是新生儿持续性肺动脉高压（PPHN）的一个可能原因。我们研究了通过给胎儿和母羊注射吲哚美辛来关闭胎羊动脉导管是否会产生PPHN的功能和结构变化。三只接受治疗的羔羊和四只未接受治疗的羔羊通过剖宫产分娩。对两只接受治疗的羔羊进行了产后血流动力学研究。分娩后肺动脉压逐渐下降，未显示出与PPHN相符的特征，而血气仍在生理范围内。然而，急性低氧血症导致肺动脉压再次升高。形态计量学分析显示，正常完全肌化的肺动脉中膜增厚，但在接受治疗的羔羊中，完全肌化的动脉没有异常延伸至腺泡内水平。总之，我们不能通过在子宫内注射吲哚美辛在新生羔羊中重现PPHN的功能和结构变化。然而，我们这种肺血管过度肌化的实验动物模型似乎有助于研究对低氧血症的血管收缩反应。
