Immunolocalization of collagenase and tissue inhibitor of metalloproteinases (TIMP) in hypertrophic scar tissue.

Normal, mature and hypertrophic dermal scars were examined by indirect immunofluorescence for the presence of collagenase, tissue inhibitor of metalloproteinases (TIMP) and cathepsin D. Significant extracellular immunoprecipitation of both collagenase and TIMP were found in areas of all scars judged to be actively remodelling, whereas inactive areas were predominantly negative. TIMP was also present in endothelial cells of patent blood vessels, but found not to be present in the enlarged endothelial cells of occluded vessels. Negligible amounts of extracellular cathepsin D were found.