Extracellular matrices in peritendinous connective tissue after surgical injury to the chicken flexor tendon.

Gene expression of fibronectin, type I collagen and type III collagen and the presence of fibronectin in peritendinous connective tissue were investigated, following flexor tendon injury, using slot-blot hybridization and immunohistochemistry. Fibrous adhesion around the chicken flexor tendon was induced by a partial laceration using a surgical knife. Total RNA was purified from the peritendinous connective tissue surrounding a tendon by combining the guanidine thiocyanate procedure and isoelectric precipitation. Slot-blot hybridization revealed that gene expression of fibronectin and collagens type I and III increased gradually after tendon injury, and levels were maintained high throughout the experimental period of 16 weeks. Indirect immunofluorescence revealed fibronectin to be preferentially located in peritendinous connective tissue around the injured tendon. The prolonged increase of fibronectin in the peritendinous connective tissue may relate to the development of histological adhesion after flexor tendon injury.