DISTRIBUTION OF FIBRONECTIN DURING WOUND-HEALING INVIVO

[摘要] The distribution of fibronectin during wound healing was studied. Full thickness wounds were made in the skin on the sides of guinea pigs'' trunks. Biopsy specimens were taken from normal skin, from a 5 h old wound and on days 1-18 after wounding. Unfixed frozen sections were analyzed for fibronectin distribution by indirect immunofluorescence analysis with a specific antiserum prepared in rabbits against guinea pig plasma fibronectin. Tissue samples were embedded in methacrylate and sections cut and stained with hematoxylin and eosin for general histology or with a silver stain for reticulin. Fibronectin was prominent in the basement membranes of normal skin epidermis. It was also present in the papillary dermis and to a lesser extent in the reticular dermis. After wounding, fibronectin was part of the fibrin clot and distributed along fibrin strands. Fibronectin was also deposited along newly synthesized collagen in the granulation tissue, which was at least in part collagen type 3 based on staining for reticulin. The entire granulation tissue was transformed into aligned collagen fibrils coated with fibronectin. Throughout the period of wound healing, the level of fibronectin associated with what appeared to be type 1 collagen in the reticular dermis adjacent to the wound area stayed about the same. When fibrils with histological characteristics of type 1 collagen were within the granulation tissue, they were coated with fibronectin. Results indicated that fibronectin was a major component present during wound healing.