应力导致关节软骨退变机制的实验研究

目的　本实验的目的是探讨应力导致关节软骨退变的病理过程与生物力学机制。方法　以 32只中国白兔为实验对象 ,在关节面施以持续高 低压应力 ,观察 4、12周 ,用组织学、组织化学、免疫组化及透射电镜为方法 ,分析退变软骨。结果　低压应力引起的退变首先表现为早期软骨细胞功能减退 ,软骨细胞代偿增生反应轻 ,然后基质破坏 ,最终导致整个软骨退变。高压应力引起的退变首先是早期基质破坏 ,软骨细胞代偿增生同时发生 ,继而软骨细胞退变 ,最终整个关节软骨退变。细胞因子主要在退变软骨的浅、移行层软骨细胞胞浆内阳性染色 ,偶可在浅层细胞近周及裂隙处见基质阳性染色。结论　高、低压应力均可导致关节软骨退变 ,低压应力首先引起软骨细胞退变 ;高压应力首先引起基质破坏。退变软骨的软骨细胞可异常合成、分泌细胞因子 ,细胞因子在软骨退变中发挥作用。

Effect of Stress on Articular Cartilage Degeneration:an Experimental Study

Objective To explore the pathological process and biomechanical mechanism of articular cartilage degeneration under stress. Methods Thirty-two adult Chinese white rabbits were involved in this study, which were divided into two groups, high compression stress group and low compression stress group. The histology, histochemistry, immunohistochemistry and TEM examination were used for observation and analysis. Results Under low compression stress the functional activity of chondrocytes were decreased in early stage, the compensational chondrocytes proliferation was only found slightly; the second change was the matrix disrupted; and at the later stage the whole cartilage was degenerated. Under high compression stress, the matrix disrupted was found at the early stage, a few chondrocytes proliferation could been seen simultaneouslyonly; and chondrocytes deganerated was followed; finally at the later stage the whole cartilage was degenerated. Immunohistochemistry staining of cytokines showed, a strong positive cytoplasmic immunoreactivity of chondrocytes in degenerated cartilage which was observed primarily in the surperficial and middle laver. Matrical positive staining was observed in the surperficial layer occasionally, particularly in the pericellular or surrounded area. Conclusion Both of high and low compression stress could induce cartilage degeneration. Under low compression stress, the initial pathological changes of cartilage were chondrocytes degeneration: under high compression stress, the matrix disrupted was found at the early stage. The chondrocytes in the degenerated cartilage can synthese and secrete cytokines abnormally. Cytokines play an important role in the process of cartilage degeneration.