Three-dimensional architecture of elastin and collagen fiber networks in the human and rat lung
Three-dimensional architecture of elastin and collagen fiber networks in the human and rat lung
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DOI：
10.1679/aohc.67.31
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发表时间：
2004-03-01
影响因子：
--
通讯作者：
Ohtani, O
中科院分区：
文献类型：
--
作者：
Toshima, M;Ohtani, Y;Ohtani, O
胶原蛋白和弹性蛋白纤维是肺结缔组织的主要成分，但它们的空间组织尚未得到很好的证明。我们使用扫描电子显微镜展示了人类和大鼠肺部胶原蛋白和弹性蛋白纤维网络的三维结构。这些网络在其原始形式提取的碱-水浸渍技术和甲酸处理，分别。胶原纤维形成延伸遍及肺和胸膜的连续体。它们在肺泡口中凝聚，在肺泡隔中细分为更小的纤维，从而形成篮状网络。肺泡隔胶原纤维网中的肺泡孔随年龄增长而增大。在萎陷的肺中，肺泡口和隔中的胶原纤维呈波浪状，而在充气的肺中，它们变成直的。弹性蛋白纤维也呈连续体，在牙槽突口丰富，在牙槽突隔中较少，纤维较直，无波浪状结构。透射电子显微镜显示胶原和弹性蛋白纤维混杂，表明这两种纤维系统可能作为平行的机械元件施加应力或应变。我们的研究结果表明，在低水平的应变的波浪状胶原纤维很容易扩展，使肺泡口和肺泡扩大，与大部分的应力被承担相邻的弹性蛋白纤维，而在较高的水平胶原纤维变得直，并限制任何进一步扩张的肺泡导管和肺泡。弹性蛋白纤维连续体似乎允许肺有效地回缩或缩回。目前的研究还表明，随着年龄的增长，肺泡孔隙扩大，提示胶原重塑可能与肺气肿的发病机制。
Collagen and elastin fibers are the major components of the lung connective tissue, but their spatial organization has not been well documented. We have demonstrated the three-dimensional architecture of collagen and elastin fiber networks in the human and rat lung using scanning electron microscopy. These networks in their original forms were extracted by an alkali-water maceration technique and a formic acid treatment, respectively. The collagen fibers formed a continuum extending throughout the lung and pleura. They were condensed in the alveolar mouth and subdivided into smaller fibers in the alveolar septa, thus forming basket-like networks. Sizes of the alveolar pores in the collagen fiber network of the alveolar septa became larger with age. In the collapsed lung, collagen fibers in the alveolar mouths and septa took on wavelike configurations, while in the inflated lung they became straight. The elastin fibers also formed a continuum, rich in the alveolar mouths and poor in the alveolar septa, were quite straight without any wavelike configuration. Transmission electron microscopy showed that collagen and elastin fibers were intermingled, suggesting that both fiber systems may act as parallel mechanical elements to stress or strain applied. Our results suggest that at low levels of strain the wavy collagen fibers are easily extended to allow alveolar mouths and alveoli to expand, with most of the stress being borne by adjacent elastin fibers, while at higher levels collagen fibers become straight and limit any further distension of alveolar ducts and alveoli. The elastin fiber continuum appears to permit the lung to effectively recoil or retract. The present study has also shown that alveolar pores enlarge with age, suggesting that collagen remodeling may be related to the pathogenesis of emphysema.