Connective tissue in aging lung

Collagen, elastin and structural glycoproteins were measured in 21 intact lungs taken at postmortem examination after sudden death from subjects aged from 15 to 83. The data were expressed as milligrams per cubic centimeter of lung peripheral parenchyma inflated and fixed at the standard pressure of 25 cm H2O to exclude the pitfall of referring to dried tissue weight. The volume/weight ratio of inflated dried lung parenchyma increased significantly with aging; likewise the collagen content decreased and so did the collagen/elastin ratio, while the elastin content did not show any significant correlation with age. The present findings indicate that biochemical, morphological and functional data on the senile lung agree well.