DYNAMIC MODULI OF RABBIT LUNG-TISSUE AND PIGEON LIGAMENTUM PROPATAGIALE UNDERGOING UNIAXIAL CYCLIC LOADING
DYNAMIC MODULI OF RABBIT LUNG-TISSUE AND PIGEON LIGAMENTUM PROPATAGIALE UNDERGOING UNIAXIAL CYCLIC LOADING
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DOI：
10.1152/jappl.1994.76.2.773
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发表时间：
1994-02-01
影响因子：
3.3
通讯作者：
FREDBERG, JJ
中科院分区：
文献类型：
--
作者：
MIJAILOVICH, SM;STAMENOVIC, D;FREDBERG, JJ
在纤维结缔组织网络中，机械负荷可以通过滑动纤维之间的摩擦从一根纤维传递到另一根纤维(J.Appl。物理。74：665-681,1993)。在这里，我们验证了这一假设；它预测纤维网络的弹性随着频率的增加而增加，随着应变幅度的增加而降低(Delta Epsilon)，并且随着组织的溶胀而减少。同样，它预测磁滞(ETA)随着频率的增加而减少，随着Delta epsilon的增加而增加，随着组织肿胀而减少，并且更重要的是，超过基质中孤立的纤维成分的滞后率。对两种结构不同的结缔组织--兔肺实质条(疏松的胶原性组织)和鸽前韧带(富含弹性蛋白的组织)的弹性和ETA进行了测量。实验覆盖了0.03125-3.125赫兹的频率范围。肺实质的弹性显著低于前韧带，随频率的对数呈线性增加，随Delta的增大而减小，而前韧带的弹性对频率和Delta epsilon均不敏感。肺实质的Eta随频率的增加而适度降低，取值与0.1相近，而前韧带的Eta为频率和Delta不变性，取值较小一个数量级。当暴露在高渗浴溶液中时，这些组织也表现出不同的机械反应。尽管预测和实验观测之间存在一些定量差异，但肺实质的动态行为总体上与网络的动态行为一致，在网络中，载荷通过滑动界面上的摩擦力从一根纤维传递到另一根纤维。
In fibrous connective tissue networks, mechanical loads may be transferred from one fiber to the next by friction between slipping fibers (J. Appl. Physiol. 74: 665-681, 1993). Here we tested that hypothesis; it predicts that elastance of fibrous networks increases with increasing frequency, decreases with increasing strain amplitude (Delta epsilon), and decreases with tissue swelling by solvent. Similarly, it predicts that hysteresivity (eta) decreases with increasing frequency, increases with increasing Delta epsilon, decreases with tissue swelling, and, importantly, exceeds that of isolated fibrous constituents of the matrix. Elastance and eta of two structurally dissimilar connective tissues were measured, the rabbit lung parenchymal strip (a loose collagenous tissue) and the pigeon ligamentum propatagiale (an elastin-rich tissue). Experiments covered the frequency range 0.03125-3.125 Hz. Elastance of lung parenchyma was substantially lower than that of propatagial ligament, increased linearly with the logarithm of frequency, and decreased with Delta epsilon; that of ligamentum propatagiale was insensitive to both frequency and Delta epsilon. eta of lung parenchyma decreased moderately with increasing frequency and assumed values of similar to 0.1, but eta of ligamentum propatagiale was frequency and Delta epsilon invariant and assumed values an order of magnitude smaller. These tissues also showed disparate mechanical responses when exposed to hypertonic bath solutions. Although there were some quantitative differences between predictions and experimental observations, the dynamic behavior of lung parenchyma was generally consistent with that of a network in which load is transferred from one fiber to the next by the agency of friction acting at slipping interface surfaces.