Gil J, Martinez-Hernandez A
J Histochem Cytochem. 1984 Feb;32(2):230-8. doi: 10.1177/32.2.6363520.
The ultrastructural distribution of specific connective-tissue components in the normal rat lung was studied by electron immunohistochemistry. Three of these components were localized: type I collagen, fibronectin and laminin. Type I collagen was present not only in major airways and vascular structures, but also in alveolar septa. Laminin was found in all basement membranes, and only in basement membranes, demonstrating once more that this glycoprotein is an intrinsic component of the basement membrane. Fibronectin was found free in the interstitium and on the surfaces of collagen fibers. The basement membranes of bronchial, glandular and endothelial cells of large vessels lacked fibronectin; however, capillary endothelial and occasionally epithelial alveolar basement membranes contained some fibronectin in an irregular, spotty distribution. This localization suggests that in the lung, as in other tissues, fibronectin is not an intrinsic component of the basement membrane, but rather a stromal and plasma protein. Only basement membranes in the alveolar parenchyma contained "trapped" plasma fibronectin.
通过电子免疫组织化学研究了正常大鼠肺中特定结缔组织成分的超微结构分布。确定了其中三种成分的定位：I型胶原、纤连蛋白和层粘连蛋白。I型胶原不仅存在于主要气道和血管结构中，也存在于肺泡间隔中。层粘连蛋白存在于所有基底膜中，且仅存在于基底膜中，这再次证明这种糖蛋白是基底膜的固有成分。纤连蛋白游离于间质中以及胶原纤维表面。大血管的支气管、腺和内皮细胞的基底膜缺乏纤连蛋白；然而，毛细血管内皮以及偶尔的肺泡上皮基底膜含有一些呈不规则斑点状分布的纤连蛋白。这种定位表明，在肺中，与其他组织一样，纤连蛋白不是基底膜的固有成分，而是一种基质和血浆蛋白。仅肺泡实质中的基底膜含有“捕获的”血浆纤连蛋白。
