Alveolar liquid and protein clearance in the absence of blood flow or ventilation in sheep.
Alveolar liquid and protein clearance in the absence of blood flow or ventilation in sheep.
复制标题
绵羊在没有血流或通气的情况下肺泡液体和蛋白质的清除率。
DOI：
10.1152/jappl.1993.74.1.176
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Matthay,MA
中科院分区：
文献类型：
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作者：
Sakuma,T;Pittet,JF;Jayr,C;Matthay,MA
这些研究的主要目的是测试通气和血流对从肺的气隙和肺内清除多余液体的贡献。首先，在麻醉绵羊中通过夹闭左主支气管消除通气后，与正常通气的对照绵羊相比，肺泡和肺液体清除率在4小时内没有改变。因此，通过肺泡上皮清除多余液体与通气产生的跨肺泡流体静压梯度的变化无关。第二，为了确定去除所有肺血流的效果，我们开发了一种新的原位绵羊肺模型，在该模型中，在绵羊放血后，在通气或不通气的情况下测量肺淋巴流量超过4小时。通过4小时内肺泡蛋白浓度增加百分比测量的肺泡液体清除率在无血流绵羊（31 +/- 18%）与肺血流正常的绵羊（31 +/- 17%）之间相似。肺淋巴流仅占转运至肺泡的过量肺泡液体清除率的10-15%，表明在无微血管滤过的情况下，非淋巴途径占过量肺液体清除率的大部分。第三，由于哇巴因完全抑制了原位绵羊肺模型中的肺泡液体清除，这些数据提供了证据表明肺泡液体清除依赖于完整的Na（+）-K（+）-ATP酶依赖性泵机制。最后，这种原位模型代表了一种独特的实验制剂，可用于研究在短时间（4小时）间隔内无血流或通气的肺泡上皮屏障。
The primary objective of these studies was to test the contribution of ventilation and blood flow to the removal of excess liquid from the air spaces and interstitium of the lung. First, after eliminating ventilation by clamping the left main bronchus in anesthetized sheep, alveolar and lung liquid clearance was not altered over 4 h compared with control sheep that were ventilated normally. Thus, removal of excess liquid across the alveolar epithelium was independent of the change in the transalveolar hydrostatic pressure gradient produced by ventilation. Second, to determine the effect of removing all blood flow to the lung, we developed a new in situ sheep lung model in which lung lymph flow was measured over 4 h with or without ventilation after the sheep had been exsanguinated. Alveolar liquid clearance, as measured by the percent increase in alveolar protein concentration over 4 h, was similar between sheep without blood flow (31 +/- 18%) compared with sheep with normal blood flow to the lungs (31 +/- 17%). Lung lymph flow contributed to only 10–15% of the clearance of the excess alveolar liquid that was transported to the interstitium, indicating that nonlymphatic pathways accounted for most of the excess lung liquid clearance in the absence of microvascular filtration. Third, because ouabain completely inhibited alveolar liquid clearance in this in situ sheep lung model, these data provide evidence that alveolar liquid clearance depends on an intact Na(+)-K(+)-ATPase-dependent pump mechanisms. Finally, this in situ model represents a unique experimental preparation that can be used to study the alveolar epithelial barrier without blood flow or ventilation for a short time (4 h) interval.