神经切除对骨形态发生蛋白异位诱导成骨的影响

[目的]通过rhBMP-2异位诱导成骨模型，观察坐骨神经和股神经切除对骨再生的影响，探讨神经支配在骨再生中的作用以及失神经所致骨折骨痂增大的部分机制。[方法]1CR小鼠36只随机分为实验组和对照组。行右侧股后部肌袋模型，实验组行右侧坐骨神经和股神经切除后植入含0．125mgrhBMP-2胶原复合物。对照组仅进行神经暴露后植入等量rhBMP-2胶原复合物。于术后7、14、21d取材，行湿重测量、放射学、生化检测、组织学观察和形态计量分析以及破骨细胞TRAP染色。[结果]湿重检测显示实验组组织块湿重明显大于对照组。X线检测实验组成骨范围较对照组明显增大，成骨组织密度不及对照组。生化检测结果显示术后第7d实验组AKP含量明显高于对照组，术后第14d，实验组钙含量高于对照组，术后21d，实验组钙、磷含量均低于对照组。组织学观察显示实验组成骨范围大于对照组，成骨后期破骨细胞活跃，骨小梁稀疏。组织形态计量分析显示实验组术后21d破骨细胞相对数增多，骨小梁体积密度、平均宽度均低于对照组。TRAP染色显示实验组破骨细胞明显较对照组活跃。[结论]在外源性BMP-2异位诱导过程中，神经切除引起骨诱导早期成骨活动的增加，在成骨中后期失神经导致破骨细胞活动增强引起骨小梁的稀疏和骨密度的降低，提示神经支配可能通过直接或间接的方式影响骨再生活动。

Effect of nerve resection on heterotopic osteogenesis induced by bone morphogenetic protein

[Objective]To observe the effect of sciatic nerve and femoral nerve resection on heterotopic osteogenesis induced by recombined human bone morphogenetic protein-2(rhBMP-2) and discuss role of never innervation on bone regeneration and partial reasons for larger callus after bone fracture accompanying denervation.[Method]A total of 36 male ICR mice were divided into experimental group and control group at random.0.125mg rhBMP-2 /collagen composites were implanted into the right thigh muscle pouches after sciatic nerve and femoral nerve section in the experimental group and after sham operation in the control group.On the 7~(th),14~(th) and 21~(st) day after implantation,roentgenographic,biochemical,histological analyses and osteoclasts TRAP staining were performed to detect the effects of sciatic nerve and femoral nerve resection on bone growth initiated by rhBMP-2.[Result]On the 7~(th),14~(th) and 21~(st) day,wet weight of new bony tissues of the experimental group was obviously greater than that of the control group.Radiography showed range of bone formation in the experimental group was larger than that in the control,but density of new bone was lower than that of the latter.Biochemical detection showed value of AKP of the experimental group was significantly higher than that of the control on the 7~(th) day,while the content of Ca of the experimental group was higher than that of the control on the 14~(th) day and the content of Ca and P of the experimental group was lower than that of the control on the 21~(st) day.Histological observation showed area of new bone of the experimental group was greater than that of the control,but trabecular bone of the former was sparser than that of the latter.Image analysis of bony tissue showed the relative number of osteoclasts in the experimental group became higher on the 21~(st) day,while volume density and width of bone trabecula in the experimental group were lower than that of the control group.TRAP staining showed osteoclasts in the new bone of the experimental group were more activated than that of the control.[Conclusion]Nerve section results in enhancement of ability of bone regeneration by BMP in the early period,but trabecular bone becomes sparse in the middle and later period because of bone resorption by osteoclasts,which indicates nerve in nervation influences bone regemeration though direct and/or indirect way.