Increased content of neutrosoluble collagen and dialyzable hydroxyproline in panacinar emphysema and spontaneous pneumothorax.

Hydroxyproline transfer to an incubation medium was studied in ten emphysematous, nine relapsing pneumothorax, and eight control samples surgically removed from 2 females and 25 males, ranging in age from 17 to 69 years. Total hydroxyproline in the lung pieces, expressed as a fraction of DNA, was not modified. A large increase of dialyzable and nondialyzable hydroxyproline fraction was observed in the incubation medium of biopsies from emphysema dn pneumothorax groups. Although the pneumothorax group had average values between controls and emphysema, some pneumothorax patients exhibited very high content of soluble hydroxyproline, suggesting a common pattern between some relapsing pneumothorax and emphysema. These findings could not be due to extracellular degradation during the processing of the samples since the results were not affected by the presence of protease inhibitors. These observations suggest that individuals with emphysema and pneumothrax have abnormalities in lung collagen structure and/or biosynthesis resulting in increased degradation of this macromolecule.