rhBMP-2对兔下颌骨牵引成骨区骨保护素表达的影响

目的：通过动物实验,研究应用外源性rhBMP-2对兔下颌骨牵引成骨区骨保护素（osteoprotegerin,OPG）的影响。方法：在48只成年大耳白兔的一侧下颌骨前部行骨切开术,分别将空白胶原、rhBMP-2 1.5mg胶原复合物植入下颌骨切开处,用牵引器延长一侧下颌骨4mm,稳定期第1、3、7、14天,分别处死各组动物,取牵引区新生骨痂行组织学及OPG免疫组化染色。结果：下颌牵引延长后牵引间隙均有新骨形成,应用rhBMP-2 1.5mg效果好。免疫组化染色OPG主要定位于成骨细胞的胞浆中。在同一时间内,应用rhBMP-2组较对照组有显著性差异（P〈0.05）。结论：动物实验表明,rhBMP-2能促进兔下颌骨牵引成骨区新骨的生成。

Effects of rhBMP-2 on Mandibular Distraction Osteogenesis and its OPG Expression in Rabbits

Objective：To investigate the effects of rhBMP-2 on mandibular distraction osteogenesis and the expression of OPG in the period of distraction osteogenesis.Methods：Unilateral mandibular osteotomies were performed in 48 mature rabbit.rhBMP-2 1.5mg with the collagen carrier was implanted in the osteotomy side of mandibles.Only collagen sponge was implanted in the control group.The mandibles of 48 rabbits were lengthened by 4mm using a distractor,The animals were killed on 1,3,7,14 days of consolidation period.The distracted calluses were harvested and processed for histological and immunohistochemistry study of OPG.Results：The regenerated bone was found in the distraction gap after mandibular lengthening.But the rhBMP-2 was better.Staining for OPG was localized in osteoblasts of the periosteal region after completion of distraction.The mandibular side treated with rhBMP-2 had greater amount of new bone formation than that treated with collagen sponge.OPG was found in the cytoplasm of osteoblasts and stained brown or dark brown by immunohistochemistry.At the same time,OPG expression indicated that there was siganificant difference between rhBMP-2 group and control group（P0.05）.Conclusion：rhBMP-2 could accelerate bone formation of mandibular distraction osteogenesis in rabbit.rhBMP-2 could increase the expression of OPG.