Synovial Cells: A Study of the Morphology and an Examination of Protein Synthesis of Synovial Cells

Abstract
Two types of synovial cells (Type 1 and 2) were distinguished in smears of cells obtained from knee joints at autopsy after trypsinization of the joint. The morphology and staining characteristics are described and these are compared with normal synovial membrane. Comparisons were also made with the ultrastructure of synovial membrane as reported by other workers. Similar types of cells were observed in both normal and pathological synovial fluid smears. Synovial cells in culture were examined. Evidence is presented for the production by synovial cells of a protein which is antigenically related to serum [alpha]2-macroglobulin. A possible role of this glycoprotein as a carrier protein to assist nutrition of articular cartilage is considered.