腰椎间盘退变动物模型的建立

目的 制备椎问盘退变动物模型.方法 将48只新西兰大白兔随机分为骨性手术组和软组织手术组.骨性手术组L4L5、L5L6为实验组椎间盘,L3L4、L6L7为自身对照组;软组织手术组L4L5、L5L6为实验对照组椎问盘.术后1、2,4及8个月行MRI及分子生物学检查.结果 (1)MRI:兔髓核位于椎间盘中央,占椎间盘横截面积50%左右.术后1、2、4及8个月,3组椎间盘横断面T2高信号区域面积分数均逐渐减小(F=96.2～1544.4,P<0.01);术后相同时间段,实验组面积分数最小,自身对照组次之,实验对照组最高,差异有统计学意义(F=125.7～1850.6,P<0.01).(2)分子生物学:蛋白多糖、胶原为椎间盘主要细胞外基质,术后1、2、4及8个月,3组椎间盘蛋白多糖、Ⅱ型胶原表达量进行性下降(F=148.2～1544.4,P<0.01),Ⅰ型胶原表达量进行性上升(F=94.3～579.6,P<0.01).术后相同时间段,实验组蛋白多糖、Ⅱ型胶原最小,自身对照组次之,实验对照组最高(F=135.5～3520.6,P<0.01);Ⅰ型胶原表达量实验组高于实验对照组、自身对照组(F=7.8～143.1,P<0.01).结论 破坏关节突关节成功制备出椎间盘退变动物模型.

Animal model of intervertebral disk degeneration caused by bilateral zygapophysial joints destruction

Objective To establish animal models of intervertebral disk degeneration caused by destroying bilateral zygapophysial joints of New-Zealand rabbits. Methods Forty-eight male New-Zealand rabbits were randomly divided into operation group on the bone and operation group on the soft tissue. In operation group on the bone,IA and L5 inferior articular pr～esses were en bloc excised,while L5 and L6 superior articular processes were retained. In the operation group on the soft-tissue,only L3 to L7 paravertebral muscles were stripped. In operation group on the bone, L4L5 and LSL6 intervertehral disks acted as experimental group,and L31A and L6L7 acted as serf-control group. In the operation on the soft tissue, LAL5 and LSL6 acted as experiment-control group. One,2,4 and 8 months post-operation,magnetic resonance imaging (MRI) and molecular biologic examination of intervertebral disks of New-Zealand rabbits were performed. Results ( 1 ) MRI: On the T2-weighted midsagittal plane images, the nucleus pnlposus was uniform high signal intensity. On the axial plane images, T2-weighted high signal area fraction of the nucleus pulposus was 50%. One,2,4 and 8 months post-operation, MRI showed the most significantly decreased axial T2-weighted high-signal area fraction in the experimental group,and the smallest declined in the experiment-cantrol group (F = 94.3-579.6, P<0.01 ). At the same time, the axial T2-weighted highsignal area fraction was the least in experiment group,whereas most in the experiment-control group (F = 125.7-1850.6,P<0.01 ). (2) Molecular biologic examination: The main extracellular matrix of intervertebral disc included aggrecan,collagen type Ⅱ and collagen type Ⅰ. One,2,4 and 8 months pest-operation, aggrecan and collagen type Ⅱ mRNA levels were decreased markedly ( F = 148.2-1544.4 ,P <0.01 ), whereas type Ⅰ collagen mRNA gradually increased ( F = 94.6-822.0, P <0.01 ). At the same time, aggrecan and collagen type Ⅱ gene expression was the least in experiment group, whereas most in the experiment-control group ( F = 135.5-3520.6 ,P <0.01 ). Collagen type Ⅰ showed the contra-tendency ( F =7.8-143.1, P<0.01 ). Conclusion By destroying IAL5 and L5L6 zygapophysial joints of adult rabbits, animal model of intervertebral disc degeneration was successfully established.