Measurement of stretch-induced loss of alveolar epithelial barrier integrity with a novel in vitro method
Measurement of stretch-induced loss of alveolar epithelial barrier integrity with a novel in vitro method
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DOI：
10.1152/ajpcell.00341.2002
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发表时间：
2002-12-01
影响因子：
5.5
通讯作者：
Margulies, SS
中科院分区：
文献类型：
--
作者：
Cavanaugh, KJ;Margulies, SS
高潮气量的机械通气会导致间质和肺泡间质水肿的形成或加重。在此之前，我们发现在体外施加大的双向变形会扰乱肺泡上皮细胞中功能性紧密连接蛋白的浓度和分布。使用一种新的方法，我们确定施加的上皮细胞应变以一种剂量和速率依赖的方式增加细胞旁的通透性。原代培养的大鼠肺泡上皮细胞分别承受12%、25%或37%的等轴循环拉伸1h，并以25%的DeltaSA进行非周期拉伸1h，在实验期间，根尖液中加入带有荧光标记的哇巴因衍生物。结合的证据表明细胞旁转运屏障的功能失效。染色面积百分比从显微镜图像中定量。循环或静态应用12%DeltaSA或25%DeltaSA的基底侧方荧光染色没有明显证据。然而，37%DeltaSA的循环拉伸比未拉伸的细胞(P<；0.0001)、12%(P<；0.0001)、25%的循环(P<；0.0005)或静态(P<；0.0005)拉伸的细胞产生更多的染色。这些结果表明，大的周期性潮气量可能会增加细胞旁的通透性，潜在地导致肺泡泛滥。
Mechanical ventilation with high tidal volumes has been shown to contribute to the formation or worsening of interstitial and alveolar edema. Previously we showed that application of large biaxial deformations in vitro perturbs the concentration and distribution of functional tight junction proteins in alveolar epithelial cells. Using a novel method, we determined that applied epithelial strain increases paracellular permeability in a dose- and rate-dependent manner. Primary rat alveolar epithelial cells were subjected to 12%, 25%, or 37% change in surface area (DeltaSA) cyclic equibiaxial stretch for 1 h. Cells were also stretched noncyclically at 25% DeltaSA for 1 h. During the experimental period, a fluorescently tagged ouabain derivative was added to the apical fluid. Evidence of binding indicated functional failure of the paracellular transport barrier. The percentage of field area stained was quantified from microscopic images. There was no significant evidence of basolateral fluorescent staining at 12% DeltaSA or at 25% DeltaSA applied cyclically or statically. However, cyclic stretch at 37% DeltaSA resulted in significantly more staining than in unstretched cells (P < 0.0001) or those stretched at either 12% (P < 0.0001) or 25% cyclic (P < 0.0005) or static (P < 0.05) DeltaSA. These results suggest that large cyclic tidal volumes may increase paracellular permeability, potentially resulting in alveolar flooding.