髓核内注射转化生长因子-β_1对兔软骨终板Ⅱ型胶原表达影响的实验研究

Experimental study on collagen Ⅱexpression of the cartilage end-plate in rabbits by injection of TGF-β_1 into nucleus pulposus

目的探讨髓核内注射转化生长因子-β1(transforming growth factor-β1,TGF-β1)对椎间失稳后软骨终板Ⅱ型胶原表达的影响作用。方法选用6月龄日本大耳白兔36只,雌雄不限,体重为(2.5±0.2)kg,随机分对照组及预防组;对照组18只,预防组18只。所有实验动物均通过切开皮肤及皮下组织,剥离骶棘肌、切断L5/6、L6/7棘上、棘间韧带、关节囊及两侧关节突关节后外1/2造成L5/6、L6/7椎间失稳模型。预防组动物在完成椎间失稳手术后立即于同一切口通过侧后方入路显露L5/6、L6/7椎间盘,并行髓核内注射TGF-β125～30μl。于术后3、6个月各取8只取材。运用免疫组织化学方法进行Ⅱ型胶原测定,用JD801图像分析系统进行分析。结果术后3个月、6个月预防组较对照组软骨终板退变明显减缓(P<0.01),软骨终板内Ⅱ型胶原有高表达(P<0.01)。结论髓核内注射TGF-β,对椎间失稳后软骨终板退变具有明显的预防作用。

Objective To investigate the effect of injection of transforming growth factor-β1 on the collagen Ⅱexpression of the cartilage end plate in rabbits following the intervertebral destabilization.Methods Forty six white macrotia rabbits of Japan were chosen,which weighed within the range of（2.5±0.2）kg,female and male was unrestricted.These rabbits were divided into 3 groups randomly,with 18 rabbits in the contrast group,18 rabbits in the preventive group,10 rabbits in the treatment group.All of the experimental rabbits were destabilized L5/6 and L6/7 via operation by cutting skin and subcutaneous tissue,splitting the sacrospinalis,cutting supraspinal or interspinous ligament,articular capsule and the bilateral articular processes.The preventive group rabbits were destabilized by operation on L5/6 and L6/7 in the same way as above,and also applied injection of TGF-β into the nucleus pulposus.After operation rabbits could freely move in the cages.Eight rabbits were chosen from the contrast group and preventive group respectively at third months and 6th months postoperatively for detecting the collogen Ⅱ expression of the cartilage end-plate with the immunohistochemistry method,which was analyzed by JD801 picture analytical system.Results The degeneration of the cartilage end-plate in the preventive group was slower（P0.01）,and collogen Ⅱ expression of the cartilage endplate was increased（P0.01） at third and sixth month postoperatively.Conclusion Injection of TGF-β1 into intervertebral discs has remarkable effect in preventing the degeneration of the cartilage end-plate due to the intervertebral destabilization.