外源性肿瘤坏死因子-α对腰椎间盘退变影响的实验研究

The in vivo effects of tumor necrosis factor-α on the degeneration of rabbit lumbar intervertebral disc

目的:探讨外源性肿瘤坏死因子-α(TNT-α)对兔椎间盘蛋白多聚糖的影响和髓核组织形态结构的变化。方法:选取40只雌性日本大白兔,体重2.5￣3kg。腹前外侧入路暴露L2/3、L3/4、L4/5和L5/6四个椎间隙共160个椎间盘,随机分别注入生理盐水、TNF-α5ng、TNF-α10ng、TNF-α20ng,分别于第2、3、5、7、10周取相应椎间盘作藏红O-快绿染色病理切片,进行形态学观察和蛋白多聚糖含量测定,注射生理盐水间盘为对照组,注射TNT-α间盘为实验组。结果:①对照组髓核蛋白多聚糖没有明显变化,实验组蛋白多聚糖下降明显(下降33.7%￣67.6%,P<0.001),并且下降程度与TNF-α注射剂量呈正相关(P<0.01)。②藏红O-快绿染色显示,随着TNF-α浓度加大,髓核中细胞数量减少,正常网状(或岛屿状)组织结构破坏越严重,空泡状结构减少,细胞核的形态由椭圆形变为多种形态,10周后部分已经转变为软骨样细胞。结论:TNF-α能够引起腰椎间盘退变,并且和退变有时效和量效关系。

Objective：To investigate the in vivo effects of TNF-α on content of aggrecan and morphology of the nucleus pulposus.Method：40 Japanese white rabbits （2.5-3kg） with a total of 160 intervertebral discs were used.L2/3,L3/4,L4/5,LS/6 intervertebral disc were exposed surgically,0.9% NaCl （5ng/μl） and various concentrations （5ng/μl, 10ng/μl and 20ng/μl） of TNF-α were respectiyely injected into L2/3 ,L3/4,L4/5 ,L5/6 intervertebral discs.All rabbits divided into 4 groups randomly based on various adminstration of TNF-α. Safranin O-fast green staining and aggrecan content neasuring were done at 2 week,3 week,5 week,7 week and 10 week respetively.Result：①Content of aggrecan has not changed apparently in control group,but in the experiment group rapid decline（by 33.7%-67.6%,P〈0.001） was evidenced,and its decline were more correlative with the dose of TNF-α （P〈0.01）. ②Safranin O-Fast Green Staining showed that,with the increase of TNF-α,the amount of nucleus pulposus cells decreased,reticular framework was broken down,vacuole shape disappeared and oval nucleolus of cells became multi-shape.Part of nucleus pulposus cells were transinducted to cartilaginoid cells after 10 week.Conclusion：TNF-α can lead to decline of aggrecan and morphological changes in the nucleus pulposus,which were related with time and dose of TNF-α adminstration.