Ultrastructural study of tension and pressure zones in a rabbit flexor tendon.

摘要: The flexor digitorum profundus tendon of the rabbit hind limb is subject to tensional forces throughout most its length but, within a localised area which in contact with calcaneum and talus, it subjected additional compressive forces. This pressure-bearing area, marked contrast areas, has fibrocartilage-like organization high concentration glycosaminoglycans (GAG). Ultrastructural features cells, collagen matrix tension pressure zones are also markedly different, full spectrum transitional characteristics junctional region between two zones. These findings support concept that cells various regions sensitive responsive changes physical load. In zone, elongated have extensive cytoplasmic flanges, may flanges neighbouring scalloped cell surface intimately conforms adjacent positively charged tightly packed fibrils long periodicity (63 nm) varying diameters. In round clustered characterized by dense arrays 11-nm-diameter microfilaments numerous lipid droplets, surrounded loosely short (53 predominantly small diameters, an rich GAG. It suggested these regional morphological variations extracellular components result from, indirectly cause of, cellular synthetic activities known occur response environment.