自制增高笼具结合双后肢大鼠建立椎间盘退变动物模型的影像学及形态学研究

Imaging and Morphologic Study of Intervertebral Disc Degeneration Model in Rats with Custom Cage and Hind Limbs

目的:探索自制笼具建立双后肢大鼠椎间盘退变动物模型的影像学和形态学特点。方法:将新生幼鼠自肱骨上段用丝线结扎,然后截去双前肢。用特制的可不断加高笼饲养,改变其饲养条件,迫使大鼠只有依靠双后肢站立才能进食和饮水的活习惯,以此训练大鼠类似于人类直立活动。2周、4周、8周、24周摄腰椎侧位片及磁共振成像检查,测定椎间隙高度指数,按Pfirrmann分级。制作组织切片,HE染色后进行组织学评估。结果:造模2周X射线片显示,腰椎生理弯曲正常,椎间隙未见明显狭窄。随着时间延长,24周时椎体边缘变锐,终板软骨下骨密度增加,部分出现骨赘。磁共振成像时椎间盘信号改变,严重者出现“黑椎间盘”。Pfirrmann分级明显增加。组织学评分不断升高。结论:特制增高笼具结合双后肢大鼠可以建立椎间盘退变动物模型,使其更接近于人体自然退变,可用于椎间盘退变的研究。

Objective:To explore the imaging and morphological characteristics of rat intervertebral disc degeneration model induced by custom-made cage and bipedal limbs.Methods:The neonatal rats were ligated from the upper humerus with silk thread,and then both forelimbs were amputated.The rats were trained to stand upright,similar to humans,by changing their feeding conditions in special cages that could be raised continuously,forcing them to eat and drink only by standing on their hind legs.Lumbar lateral radiographs and MRI were taken at 2,4,8 and 24 weeks to determine the disc height index and Pfirrmann grade.Tissue sections were prepared and histologically evaluated after HE staining.Results:The imaging test at 2 weeks showed physiological curvature of spine was normal,and no obvious narrowing of vertebral space was observed.While at 24 weeks the vertebral edges became sharper,and the subchondral osteosclerosis,and some osteophytes appeared.On MRI,the disc signal decreased,and in severe cases,“black disc”appears.Pfirrmann grading increased significantly.Histological scores increased continuously.Conclusion:The animal model of intervertebral disc degeneration can be established with custom-made cage and bipeda limbs,which is simulated to the natural degeneration of human,and can be used for the study of intervertebral disc degeneration.