FATE OF NEWLY SYNTHESIZED LUNG COLLAGEN AFTER ENDOTRACHEAL ADMINISTRATION OF PROLINE-C-14 TO HAMSTERS

Abstract
The endotracheal administration of 14C-proline to young adult golden hamsters was effective in radiolabeling collagen and resulted in a greater specific activity for hydroxyproline than did i.p. administration of the amino acid. The isolation of purified insoluble collagen was accomplished with the aid of pancreatic elastase. Enzyme treatment of lung homogenates resulted in the solubilization of 35% of total lung collagen. The residue obtained after elastase treatment was pure collagen. A significant portion of the radiolabeled collagen was solubilized by the elastase treatment, which suggests that elastase may be helpful in distinguishing between newly synthesized and total lung collagen. Studies performed at various times after administration of 14C-proline indicate that a greater portion of the collagen radioactivity is solubilized during the early days after treatment with the amino acid. The methodology and procedures outlined in this communication allow for additional insights into the metabolism of connective tissue, specifically collagen, in normal and diseased lungs.