EFFECT OF CHRONIC HYPOXIA ON PULMONARY VASCULAR PRESSURES IN ISOLATED LUNGS OF NEWBORN PIGS
EFFECT OF CHRONIC HYPOXIA ON PULMONARY VASCULAR PRESSURES IN ISOLATED LUNGS OF NEWBORN PIGS
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DOI：
10.1152/jappl.1994.77.6.2853
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发表时间：
1994-12-01
影响因子：
3.3
通讯作者：
KAPLOWITZ, MR
中科院分区：
文献类型：
--
作者：
FIKE, CD;KAPLOWITZ, MR
我们的目的是确定慢性肺泡缺氧是否改变新生猪肺的肺血管压力，评估平滑肌张力对肺血管压力改变的贡献，并检查慢性缺氧是否改变肺血管对急性缺氧的反应性。我们保持24至72小时龄的猪在充满室内空气（对照）或11- 12%O-2（慢性缺氧）的3-5（短）或10-12（长）天。我们使用离体肺，应用微穿刺和血管闭塞技术，测量10- 30 μ m直径的小静脉的压力，以及在加入平滑肌扩张剂罂粟碱之前和之后，或在用低氧气体混合物对肺充气之前和之后的流入闭塞和流出闭塞压力。对于短时间组和长时间组的猪，肺动脉压是唯一在慢性缺氧中比对照肺更大的血管压。平滑肌张力增加是肺动脉压变化的主要来源，而形态学的变化有助于肺动脉压的变化与长期缺氧。新生猪暴露于不同时间的肺泡缺氧是研究新生儿和婴儿出生后肺动脉高压的有用模型。
Our purposes were to determine whether chronic alveolar hypoxia altered pulmonary vascular pressures in lungs of newborn pigs, evaluate the contribution of smooth muscle tone to alterations in pulmonary vascular pressures, and examine whether chronic hypoxia altered pulmonary Vascular reactivity to acute hypoxia. We kept 24- to 72-h-old pigs in chambers filled with room air (control) or 11-12% O-2, (chronic hypoxia) for either 3-5 (short) or 10-12 (long) days. We used isolated lungs and applied micropuncture and vascular occlusion techniques to measure pressure in 10- to 30-mu m-diam venules and inflow occlusion and outflow occlusion pressures before and after the addition of the smooth muscle dilator papaverine or before and after inflation of the lungs with a hypoxic gas mixture. For pigs in both the short and long groups, pulmonary arterial pressure was the only vascular pressure that was greater in chronically hypoxic than in control lungs. Increased smooth muscle tone was the primary source of the change in pulmonary arterial pressure with short hypoxia, whereas morphometric changes contributed to the change in pulmonary arterial pressure with long hypoxia. Exposure of newborn pigs to different lengths of alveolar hypoxia is a useful model to study postnatal pulmonary hypertension in newborns and infants.