Composite epithelial and endothelial basal laminas in human lungs. A structural basis for their separation and apposition in reaction to injury.

摘要: A new method for electron microscopic identification of endothelial basal lamina has been developed by treating fresh human lung tissues with 5 M guanidine HCl, pH 7.2, at 20 C 24 hours. The treatment causes significant differential swelling and substantial decrease in density the makes latter readily distinguishable from epithelial lamina. In thin part alveolar septums, unit shared epithelium on one side endothelium other is found to be composed discrete layers close apposition. There no structural modification site laminas septums seem two independent scaffold systems distinct identities despite frequent physical contact. findings provide a basis considering separation apposition reaction injury pathogenesis alveolocapillary block.