椎间盘内破裂动物模型的建立及行为学观察

The establishment of animal model for internal disruption of intervertebral disc and its ethological observation

目的建立椎间盘内破裂的动物模型,观察其病理学及行为学表现。方法实验用雄性SD大鼠96只,随机分为3组,每组32只。假手术组(对照组),全麻后取仰卧位,经腹腔正中入路,钝性撕开后腹膜,暴露L_(6～7)椎间盘,逐层缝合。椎间盘轻度破坏组(手术1组),全麻后取仰卧位,经腹腔正中入路,暴露L_(6～7)椎间盘。于椎间盘前正中点以直径0.2mm的特制针头刺入L_(6～7)椎间盘至后侧纤维环下,深度控制为3mm。少许明胶海绵堵塞针口,逐层缝合。关腹前滴入约1ml左右生理盐水。椎间盘重度破坏组(手术2组),全麻后取仰卧位,经腹腔正中入路,暴露L_(6～7)椎间盘。于椎间盘前正中点以直径0.2mm的特制针头刺入L_(6～7)椎间盘至后侧纤维环下,深度控制为3mm。仍以前正中针口为刺入点,与第一针道各成30°角向左右分别穿刺至后外侧纤维环下。结果手术椎间盘内可见由前方至后方的裂隙,后侧的外层纤维环未破裂。术后髓核内纤维组织样细胞透明样变性,与胶冻状物交织在一起,内层纤维软骨细胞变性。椎间盘内破裂模型手术2组的大鼠术后静止不动时间延长、运动时间减少,同假手术组相比,有统计学意义。结论建立了一种椎间盘内破裂的动物模型,并观察了手术间盘的病理及行为学改变过程,该模型可模拟临床上的椎间盘源性下腰痛。

Objective To establish animal model for internal disruption of intervertebral disc, and to observe the pathological and ethological manifestations. Methods 96 male experimental Sprague Dawley rats （SD rats） were randomly divided into three groups, and each group included 32 rats. With respect to control group, all rats were taken supine position after general anaesthesia. Central approach through abdominal cavity was adopted and the posterior peritoneum was torn open bluntly to expose L6_7 intervertebral discs. Layer-by-layer suture was conducted. In the group with light intervertebral disc damage （surgery group 1）, all rats were taken supine position after general anaesthesia. Central approach through abdominal cavity was adopted to expose L6.7 intervertebral discs. From the mid-point of anterior intervertebral disc, specially made pinhead with diameter being 0.2 mm was pricked into L6_7 intervertebral discs and eventually reached the site below posterior annular fibrosus. The depth was controlled to be 3 mm. A small amount of gelfoam was used to jamp up the pinhead opening. Layer-by-layer suture was conducted. Before the abdominal cavity was closed, about I ml normal saline was dropped in. In the group with severe intervertebral disc damage （surgery group 2）, all rats were taken supine position after general anaesthesia. Central approach through abdominal cavity was adopted to expose L6_7 intervertebral discs. From the mid-point of anterior intervertebral disc, specially made pinhead with diameter being 0.2 mm was pricked into L6.7 intervertebral discs and eventually reached the site below posterior annular fibrosus. The depth was controlled to be 3 mm. Results Fissures from front to rear were visible in intervertebral discs applied with surgery. No rupture of outer annular fibrosus on the posterior side occurred. Postoperatively, degeneration of hyaloid sample cells of fibrous tissue in nucleus pulposus occurred. Degenerated hyaloid sample cells of fibrous tissue in nucleus pulposus were interlaced with gelatum-like substance. The intimal fibrocartilage cells degenerated. For rats in surgery group 2, the time of immobility prolonged, while the time of locomotion decreased. Compared with the rats in control group, statistical significance existed. Conclusions A sort of animal model for internal disruption of intervertebral disc is established. Processes of pathological and ethological changes are observed. This model can simulate the clinical discogenic low back pain.