Ultrastructural Characterization of the Rabbit Mandibular Condyle following Experimental Induction of Anterior Disk Displacement
Ultrastructural Characterization of the Rabbit Mandibular Condyle following Experimental Induction of Anterior Disk Displacement
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DOI：
10.1159/000016765
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发表时间：
2000-07
影响因子：
2.7
通讯作者：
M. Sharawy;Ayman M. Ali;Won-Seok Choi;V. Larke
中科院分区：
文献类型：
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作者：
M. Sharawy;Ayman M. Ali;Won-Seok Choi;V. Larke
我们实验室之前的研究表明，手术诱导兔颅下颌关节（CMJ）中的前椎间盘移位（ADD）会导致与骨关节炎一致的细胞和细胞外改变。在人类 ADD 以及其他关节的骨关节炎中也有类似的发现。本研究的目的是在超微结构水平上进一步表征这些组织病理学发现。手术暴露15只兔子的右关节，切断除后附着点外的所有椎间盘附着物。然后将椎间盘重新定位在前面并缝合到颧弓。左关节作为假手术对照。十个额外的关节用作非操作控制。手术后两周切除下颌髁突并进行透射电子显微镜检查。与对照组相比，实验髁显示出新血管形成、细胞外基质纤维颤动和空泡化，以及凋亡细胞数量增加。此外，骨关节炎软骨中的软骨细胞显示粗面内质网和高尔基复合体数量增加，表明蛋白质合成增加。骨关节炎软骨中存在粗胶原纤维，支持了我们之前的免疫组织化学结果，即存在 I 型胶原蛋白，而不是通常存在的 II 型胶原蛋白。结论是，手术诱导兔 CMJ 中的 ADD 会导致下颌髁突软骨的超微结构变化，与已知的骨关节炎中发生的退行性改变一致。
Previous studies in our laboratory have shown that surgical induction of anterior disk displacement (ADD) in the rabbit craniomandibular joint (CMJ) leads to cellular and extracellular alterations consistent with osteoarthritis. Similar findings were also reported in human ADD as well as osteoarthritis of other joints. The purpose of this study was to further characterize these histopathological findings at the ultrastructural level. The right joint of 15 rabbits was exposed surgically and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. Ten additional joints were used as nonoperated controls. Mandibular condyles were excised 2 weeks following surgery and processed for transmission electron microscopy. Experimental condyles showed neovascularization, fibrillation and vacuolation of the extracellular matrix and an increase in the number of apoptotic cells compared to controls. In addition, chondrocytes in osteoarthritic cartilage showed an increase in the amounts of rough endoplasmic reticulum and Golgi complex suggesting an increase in protein synthesis. The presence of thick collagen fibers in osteoarthritic cartilage supports our previous immunohistochemical results of the presence of type I collagen instead of normally existing type II collagen. It was concluded that surgical induction of ADD in the rabbit CMJ leads to ultrastructural changes in the mandibular condylar cartilage consistent with degenerative alterations known to occur in osteoarthritis.