| Abstract: | Lung samples from four infants who died of respiratory complications of prematurity (Infant Respiratory Distress Syndrome, IRDS) were analyzed for their content of various collagen crosslink amino acids by newly developed techniques of high-performance liquid chromatography. Comparable analyses were performed with tissue from stillborn infants with apparently normal lungs (control group) and from adults without apparent lung disease. We observed increased amounts of the difunctional crosslink dihydroxylysinonorleucine (DHLNL) in the IRDS lungs. Gestational age seemed to be the most important determinant of total lung content of the trifunctional crosslink hydroxypyridinium (OHP). Term infants had about one-third of the OHP content in their lung collagen as was found in the adult lungs. These observations suggest that there are important changes in the molecular structure of collagen in human fibrotic lung disease, changes that are paralleled in various animal models of experimental pulmonary fibrosis, and in various human diseases involving abnormalities of skin or bone collagen metabolism. |
