Feitosa VeraLúciaC, Vidal Benedicto C, Pimentel Edson R
Department of Morphology, Federal University of Sergipe-UFS, Aracaju, Brazil.
J Anat. 2002 Jan;200(Pt 1):105-11. doi: 10.1046/j.0021-8782.2001.00006.x.
The proximal region of the superficial digital flexor tendon of pigs passes under the tibiotarsal joint, where it is subjected to compressional and tensional forces. This region was divided into a surface portion (sp), which is in direct contact with the bone and into a deep portion (dp), which is the layer opposite the articulating surface. The purpose of this work was to analyse the distribution and organisation of the collagen bundles and proteoglycans in the extracellular matrix in sp and dp. Toluidine-blue-stained sections were analysed under a polarising microscope. Strong basophilia and metachromasia were observed in sp, demonstrating accumulation of proteoglycan in a region bearing compression, but the intensity was reduced the further layers were from the bone. Linear dichroism confirmed that the glycosaminoglycan molecules were disposed predominantly parallel to the longest axis of the collagen fibrils. Birefringence analysis showed a higher molecular order and aggregation of the collagen bundles in areas where the tension was more prominent. The crimp pattern was more regular in dp than in sp, probably as a requirement for tendon stretching. The optical anisotropy exhibited by the collagen bundles also confirmed the helical organisation of the collagen bundles in the tendon. Hyaluronidase digestion caused a decrease in the basophilia, but this was not eliminated, supporting the idea that in the matrix, proteoglycans are not completely available to the enzyme action.
猪指浅屈肌腱的近端区域从胫跗关节下方穿过，在此处承受压缩力和拉力。该区域分为与骨直接接触的表层部分（sp）和与关节面相对的深层部分（dp）。本研究的目的是分析sp和dp细胞外基质中胶原束和蛋白聚糖的分布及组织情况。对甲苯胺蓝染色切片在偏光显微镜下进行分析。在sp中观察到强烈的嗜碱性和异染性，表明在承受压缩的区域有蛋白聚糖积累，但离骨越远的层强度越低。线性二向色性证实糖胺聚糖分子主要与胶原原纤维的最长轴平行排列。双折射分析表明，在张力更显著的区域，胶原束的分子有序性和聚集程度更高。dp中的卷曲模式比sp中的更规则，这可能是肌腱伸展的需要。胶原束表现出的光学各向异性也证实了肌腱中胶原束的螺旋结构。透明质酸酶消化导致嗜碱性降低，但并未消除，这支持了基质中的蛋白聚糖并非完全可被酶作用的观点。
