B-cells of the synovial membrane: III. Relationship with the specific collagenous structure of the intimal interstitium in the mouse

An ultrastructural study of the synovial membrane in mice revealed that, in addition to specific polypeptide-producing secretory cells (B-cells), the intima is characterized by a specific differentiation of the interstitium adjacent to the synovial cavity. Scattered collagen fibrils are embedded in a fine fibrillar material, which often appears as cross-striated strands resembling longspacing-collagen (periodicity from 90 to 120 nm). Similar material was found along the synovial cavity in the rat, guinea pig, rabbit and man. The close relationship between this material and B-cells observed in the mouse suggests that the maintenance of the specialized intimal interstitium may depend on the secretory function of B-cells.