ABSTRACT
Few studies have discussed the relationship between the molecular organization and the physicochemical and biomechanical properties of pig tendons. In this work, we examined the extracellular matrix of the deep digital flexor tendon of pigs, which was subjected to tensional (proximal region) and compressive (distal and terminal regions) forces. The three regions of the tendon were used for swelling tests and their glycosaminoglycan content was determined. Longitudinal sections of the tendon were stained and observed using polarized light microscopy. The distal and terminal regions were swole more in water than the proximal region. After staining with toluidine blue the metachromasy was more intense in the distal and terminal regions, indicating an accumulation of proteoglycans in these regions. Analysis of the glycosaminoglycans by agarose gel electrophoresis showed that dermatan sulfate was present in all regions, whereas chondroitin sulfate occurred only in the regions of compression. The shape of the fibroblasts changed along the tendon: rounded cells occurred in regions under compression, while in the region under tension, elongated cells predominated. The organization and distribution of the collagen bundles were different for each region. Birefringence analysis revealed a more regular crimp pattern in the region under tension than in the regions under compressive forces. The elastic fibers also showed a different distribution in each region. These results indicate that the regional differences in the structure and composition of the deep digital flexor tendon of pigs are related to the biomechanical properties of the tendon.
Subject(s)
Animals , Collagen , Muscle Fibers, Skeletal , Proteoglycans , Tendons/anatomy & histology , Tendons/cytology , Tendons/ultrastructure , Weight-Bearing/physiologyABSTRACT
1. Lectins labeled with colloidal gold particles were used for the ultrastructural evaluation of the biological effects of GaAs softlaserirradiation on the healing of dog tendon wounds. 2. Six dogs were submitted to tenotomy and tenorrhaphy on the right and left hind legs. All animals received laser irradiation (4J/cm²) daily for ten days only on the left leg, and the right leg of the same animal was used as control. Biopsies were taken 11, 22 and 40 days after surgery. 3. Laser-irradiated and control tendon tissues were embedded in L.R. White resin and thin section were incubated in the presence of gold-labeled Arachis hypogaea (PNA), Canavalia ensiformes (Con A) and Triticum vulgare (WGA). 4. In general, the control and laser-irradiated tissues presented homogeneous and similar labelling of heterochromatin, rough endoplasmic reticulum and extracellular matrix. 5. We conclude that GaAs softlaser irradiation does not produce significant changes in the glycosylation of healing tendons
Subject(s)
Dogs , Animals , Male , Female , Lasers , Lectins , Tendons/radiation effects , Wound Healing/radiation effects , Collagen/radiation effects , Collagen/ultrastructure , Extracellular Matrix/radiation effects , Extracellular Matrix/ultrastructure , Fibroblasts/radiation effects , Fibroblasts/ultrastructure , Gold Colloid , Microscopy, Electron , Staining and Labeling , Tendons/surgery , Tendons/ultrastructure , Time FactorsABSTRACT
Ultra-estrutura da junçäo músculo-tendínea em diafragma de coelho. Os autores estudam, no presente trabalho, a ultra-estrutura da junçäo músculo-tendínea do diafragma de coelho. Na extremidade da fibra muscular, o sarcolema apresenta várias fendas e invaginaçöes como dedos de luva. As fibrilas colágenas do tendäo säo sinuosas e estäo inseridas obliquamente na superfície externa da lâmina basal do sarcolema. Esta disposiçäo parece estar relacionada ao mecanismo de transmissäo de tensäo. Na extremidade da fibra muscular, miofibrilas ramificam-se e prendem-se no sarcolema