内侧副韧带切断合并半月板部分切除对大鼠膝关节软骨、滑膜和细胞因子的影响

目的:观察内侧副韧带切断合并半月板部分切除对大鼠膝关节软骨、滑膜和关节液中细胞因子的影响。方法:20只SD大鼠,行内侧副韧带切断和内侧半月板部分切除术,分别在术后第1、2、3、4和5周各处死4只大鼠并取材;另备4只作为正常对照。组织学观察其关节软骨和滑膜的变化,酶联免疫吸附法(ELISA)测定关节液中细胞因子白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)表达。结果:膝关节内侧副韧带切断和部分半月板切除后,大鼠关节液中IL-1β和TNF-α表达显著增高,TNF-α在术后第1周时、IL-1β在术后第2周时达到峰值,然后逐渐下降,第5周时仍显著高于正常对照水平。术后第1周,关节软骨丢失,软骨层变薄;软骨细胞减少,排列层次紊乱,有簇聚现象;蛋白多糖分泌减少,表面的软骨组织甲苯胺蓝染色失染。第2周,软骨继续退变,表面软骨纤维化,软骨下骨硬化,部分侵入软骨层,蛋白多糖进一步丢失,甲苯胺蓝染色失染严重。从第3周开始,正常的软骨细胞基本消失,呈纤维样变,软骨下骨硬化;髓腔融合、开放、纤维化,呈现晚期骨性关节炎的改变。滑膜细胞从术后第1周开始增生,炎细胞浸润;第2周滑膜炎症加重,并有血管增生;第3周滑膜已出现明显的纤维化改变。结论:内侧副韧带切断伴内侧半月板部分切除后,大鼠膝关节呈现骨性关节炎的改变,关节液中IL-1β和TNF-α表达显著增高。

The Effect of Medial Collateral Ligament Transection in Combination of Partial Medial Meniscectomy on the Cartilage, Synovium and Cytokines of Knee Joint

Objective To sduty the histological change of cartilage and synovium of knee joint and the induction of cytokines in synovial fluid in experimental animals with osteoarthritis(OA)caused by transection of the medial collateral ligament and partial medial meniscectomy.Methods Transection of the medial collateral ligament and partial medial meniscectomy of knee were performed in 20 SD rats.The specimens were collected on week 1,week 2,week 3,week 4,and week 5 after operation.The morphological change of cartilage and synovium were investigated,and the enzyme-linked immunosorbent assay(ELISA) was performed to measure the expression of cytokines such as IL-1β and TNF-α in synovial fluid.Results A rapid expression of TNFα followed by IL-1β was seen,with peak values of TNF-α on week 1,and of IL1β on week 2 after operation,then the expression of TNF-α and IL-1β was gradually decreased but still highly expressed as compared with that in normal joint.Specimens of cartilage on week 1 showed morphologic degeneration with loss of cartilage and chondrocytes,disarrangement of chondrocytes with formation of cluster and loss of proteoglycan which resulted in destaining of toluidine blue staining at superficial cartilage.On week 2 after operation,degeneration of cartilage was more severe with fibrosis of superficial cartilage and invasion into cartilage with subchondral bone,sclerosis of subchondral bone,reduction of proteoglycan resulting in mostly destaining of toluidine blue staining.From the commencement of week 3,the cartilage showed the characteristic of later OA morphologically with fibrosis of cartilage,sclerosis of sunchondral bone,amalgamation,opening and fibrosis of marrow cavity.The synovium revealed hyperplasia of synoviocytes and infiltration of inflammatory cells on week 1 and aggregative inflammation accompanied with vascularization on week 2.From week 3,extensive fibrosis was presented in synovium.Conclusion The morphological change of knee with transection of the medial collateral ligament and partial medial meniscectomy in the study demonstrated the characteristic OA,and the expression of TNF-α and IL-1β in synovial fluid was increased at the same time.