Histological and Ultrastructural Differences between Normal and Softened Articular Cartilage

正常與軟化關節軟骨之組織與超微結構差異研究

王志龍(Jue-Long Wang) ； 王志生(Jyh-Seng Wang) ； 張奐(Huann Chang) ； 詹瑞棋(Rai-Chi Chan) ； 徐道昌(Tao-Chang Hsu)

《中華民國復健醫學會雜誌》 28卷1期 (2000/03) Pp. 1-10

摘要

關節軟骨是一個高度承受壓力的組織，藉著特殊三度空間結構的膠原纖維以及鑲嵌在其中富含水份的多醣蛋白大型分子，以特有的相互結合作用達成高度承受壓力的特性。膠原纖維網絡遭受外力而喪失特殊聯結性後，將會減低對多醣蛋白區域水腫傾向的約制力，進而導致組織水腫、軟骨基質的硬度降低，甚至組織在承重的情形下尚能維持含水厚度能力的減退。
退化關節炎的一個重要表徵，就是軟骨的軟化及水腫，而退化過程的病理發現就是膠原網路的崩解或破損。本研究的目的，就是在探尋正常與軟化軟骨基質的一般組織結構與超微結構之差異。我們選取了25組牛的股骨髁及脛骨髁軟骨層，針對其正常與軟化的軟骨加以觀察分析。在Nomarski立體光學顯微鏡下，正常的軟骨基質幾乎是無特定方向及形狀的紋理；而軟化的軟骨基質則出現微細的纖維結構，形狀上呈現放射狀排列及充滿重疊的縐折與波浪狀，深層軟骨細胞拖尾的形狀較正常更為明顯。進一步，在穿透式電子顯微鏡下，正常的軟骨基質顯現重覆斜式交錯的纖維節段，構成仿若隨意排列的網絡；相對地，在軟化的軟骨上則存在著擴張、平行且不緊密纏繞的節段。
本篇深刻且詳細的觀察組織及超微結構，是一連串退化軟骨研究的起點，可進一步做為將來觀察各種環境因素對軟骨造成變化的基準。

關鍵字

關節軟骨 ； 牛 ； 超微結構

並列摘要

Articular cartilage is a highly compressive load-bearing tissue by virtue of the functional interplay between a 3-dimensional (3-D) structure of collagen fibrils and the entrapped water-swollen proteoglycan macromolecules. Any loss of interconnectivity in the collagen network that might reduce the constraints on the swelling tendency of the proteoglycan domain will lead to swelling and low matrix stiffness. The 3-D fibrillar architecture of the cartilage matrix strongly influences its stiffness and therefore its ability to maintain a sufficient hydrated thickness under load.
One of the pathologies of osteoarthritis is softening and swelling of the articular cartilage. Such degenerative process is thought to involve a major disruption or breakdown of the collagen network. Any rigorous description of the mechanisms responsible for the degenerative breakdown of the healthy cartilage matrix will include a detailed understanding of the ultrastructural steps that transform the normal fibrillar architecture into one that is unable to resist the normal pattern of forces transmitted through the joint system.
The purpose of the present study is to investigate structural and ultrastructural differences between the normal and softened matrix. Under Nomarski light microscopy, the general matrix of normal cartilage was characterized by an almost non-directional, ground glass or amorphous texture. In contrast, the general matrix of the softened cartilage exhibited a fine, fibrous texture and with a strong radial alignment which often contained a superimposed crimp or waveform. The tail of the cells in this softened cartilage appeared more evident than in the normal cartilage. Under transmission electron microscopy, the normal matrix appeared with repeating fibril segment obliquity and thus creating a pseudo-random network. In contrast, the general matrix of the softened cartilage featured the presence of extensive, parallel and relatively unentwined fibril segments. The result of this study provides a guideline for further research on histological and ultrastructural changes of the articular cartilage that might be affected by many environmental factors.

並列關鍵字

articular cartilage ； bovine ； ultrastructure