An immunohistochemical study of the collagens of rabbit synovial interstitium.

The interstitial pathway from joint cavity to synovial transport vessels contains a complex extracellular matrix. Rabbit knee synovial intima contains 3 fibrous elements--banded collagen fibrils, microfibrils and broad banded aggregates. The distribution of 4 types of collagen in rabbit knee synovium was investigated immunohistochemically. Types I and III collagens are both present, although the binding of anti-type I antibody was weak. Type V collagen, which forms thin fibrils, or is copolymerized with type I collagen, and type VI collagen, which forms broad banded aggregates and microfibrils, are widely distributed throughout the intimal and subintimal matrices.