Elastic moduli of lungs during postnatal development in the piglet.
Elastic moduli of lungs during postnatal development in the piglet.
复制标题
仔猪出生后发育过程中肺的弹性模量。
DOI：
10.1152/jappl.1989.67.4.1422
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Pipkin,AC
中科院分区：
文献类型：
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作者：
Mansell,AL;Moalli,RR;Calista,CL;Pipkin,AC
婴儿期肺部疾病的几种表现表明，新生儿肺部的机械相互依赖性可能相对较高。为了测试这种可能性，我们测量了弹性模量和胸膜张力从小猪年龄范围从小于12小时到85天的肺切除。接近最大充气时，新生儿肺（小于12小时，n = 6）没有检测到胸膜张力，尽管3至5天大的肺（n = 6）张力大于5，000 dyn/cm。相比之下，新生儿肺的实质回缩更大[19.3 +/- 3.0（SD）vs. 14.3 +/- 2.4 cmH 2 O，90%最大充盈体积，P <0.01]。与3至5天大的肺相比，新生儿肺的剪切模量较高（在15 cmH 2 O跨肺压下为13.5 +/- 4.6 vs. 9.2 +/- 1.5 cmH 2 O，P小于0.05），并且泊松比较低。出生后3 - 85天的肺生长特征为：1）恒定的剪切模量（0.6倍的跨压）; 2）体积模量降低（从6.8倍到5.1倍的跨压，P小于0.005）; 3）在逐渐升高的跨压下有气体捕获的证据。因此，猪肺中实质的生长与体积变化的刚度降低相关，但对形状变化的总体刚度没有影响。然而，相对较大的刚度，形状变化发生短暂的新生仔猪肺。
Several manifestations of lung disease during infancy suggest that mechanical interdependence can be relatively high in newborn lungs. To test this possibility, we measured elastic moduli and pleural membrane tension in lungs excised from piglets ranging in age from less than 12 h to 85 days. Near maximum inflation, newborn lungs (less than 12 h, n = 6) had no detectable pleural membrane tension, although 3- to 5-day-old lungs (n = 6) had tension greater than 5,000 dyn/cm. In contrast, parenchymal recoil was greater in the newborn lungs [19.3 +/- 3.0 (SD) vs. 14.3 +/- 2.4 cmH2O at 90% of maximum inflation volume, P less than 0.01]. Shear moduli were higher (13.5 +/- 4.6 vs. 9.2 +/- 1.5 cmH2O at 15 cmH2O transpulmonary pressure, P less than 0.05) and Poisson ratios were lower in the newborn lungs as compared with the 3- to 5-day-old lungs. Postnatal lung growth between 3 and 85 days was characterized by 1) a constant shear modulus (0.6 times transpulmonary pressure); 2) decrease in the bulk modulus (from 6.8 to 5.1 times transpulmonary pressure, P less than 0.005); and 3) evidence of gas trapping at progressively higher transpulmonary pressures. Therefore, growth of parenchyma in the piglet lung is associated with reduced stiffness to volume change but with no effect on overall stiffness to shape change. Nevertheless, a relatively great stiffness to shape change occurs transiently in newborn piglet lungs.