The Ultrastructure of Equine Synovial Membrane

Abstract

HorIcyD.,F. Tichy: The Ultrastructure of Equine SynovialMembrane. ActavetBmo,I995,64:225-229.The ultrastructure of synovial membrane was studied in two adult stallions of the English thorougbred horse. Samples were collected from 2 astragalar and 2 knee joints of stallions. The equine synovial membrane was composed of two cell types, A and B, and the synovial matrix which extended into subsynovial tissue. Synoviocytes,located singly, were usually covered with synovial matrix; they were in contact with the joint cavity only occasionally. A-cells showed a structure generally similar to the mammalian cells of this type but they were flatter and had no cytoplasmic projections. The cytoplasm of B-cells was free of secretory granules and lacked fibrils passing through the plasma membrane. The synovial matrix of the surface layer showed numerous dense bodies. The occurrence of thick bundles of aperiodic filaments which were several Jlll1long and 0.2-0.3 Jlll1 thick was an unusual finding.