大鼠下颌骨牵引成骨过程中血管生成机理的研究  

A study of angiogenesis in rat mandibular distraction osteogenesis

作　　者：祝为桥[1] 王兴[2] 

机构地区：[1]北京同仁医院口腔科,100730 [2]北京大学口腔医院正颌外科中心

出　　处：《现代口腔医学杂志》2010年第3期180-183,共4页Journal of Modern Stomatology

摘　　要：目的研究下颌骨牵引成骨过程中血管生成的机理。方法 42只成年雄性SD大鼠下颌骨牵引成骨模型,牵引程式:间歇期5天,牵引速度0.2mm×2次/天,牵引期6天,稳定期4周。分别于间歇期结束(术后第5天)、牵引期结束以及稳定期第1、2、3和4周六个时间点切取标本,X线检查后进行制片,HE染色、层粘连蛋白免疫组化血管标记,血管内皮生长因子(vascular endothelial growth factor,VEGF)免疫组化染色,实时定量反转录聚合酶链式反应(real-time quantitative reversetranscript polymerase chain reaction,RQ-RT-PCR)检测并分析VEGFmRNA的表达。结果间歇期结束即可见毛细血管长入,成骨过程中新生骨前缘可见大量血管标记,同时可见血管管径增大,新生骨髓腔内可见大量血管标记;VEGF在活跃成骨细胞、髓腔衬里细胞和血管内皮细胞表达;间歇期第5天VEGF表达显著上调,牵引期结束VEGF表达进一步升高,至稳定期第1周和第2周时VEGF表达达到峰值,此后VEGF表达开始下降至稳定期第4周结束时其表达水平已接近对照组。结论牵引成骨过程中血管生成和骨生成有着密切的伴随关系,血管生成要先于骨生成,这种关系是成骨细胞和血管内皮细胞通过VEGF的分子水平相互作用的结果;稳定期第1和第2周是血管生成的高峰期。Objective To study the mechanism of angiogenesis in mandibular distraction osteogenesis.Methods Osteotomy was performed and external distractor was used on the mandibles of 42 adult male SD rats. After a 5-day latency period,the distractor was activated at a rate of 0.4mm/day for 6 days,followed by a 4-week consolidation period. Radiograph was taken,and specimens were harvested at the end of the latency period,when distraction was completed,and at the end of 1,2,3 and 4 weeks of the consolidation period. Vessels in distraction space were marked by laminin immunohistochemistry staining. Temporospatial expression of vascular endothelial growth factor （VEGF） was investigated by using immunohistochemistry and real-time quantitative reverse transcription polymerase chain reaction （RQ RT-PCR）. Quantitative analysis was used to characterize VEGF expression.Results Capillaries were detected between the bone stumps at the end of latency and were also detected in adjacent to the osteoblasts in the frontier of new bone formation. The vessels＇ diameter was increased in consolidation period. Strong signal of VEGF was co-localized in osteoblasts,endothelial cells and bone cavities lining cells. VEGF expression was sharply increased in latency periods and increased steadily to peak level during 1 to 2-week consolidation period,thereafter VEGF expression was decreased.Conclusion Bone formation is accompanied by the angiogenesis,angiogenesis was superior to osteogenesis which may caused by the ＇cross-talk＇ between osteoblasts and endothelial cells through VEGF. The most activated angiogenesis takes place in 1 to 2-week consolidation period during distraction osteogenesis.

关 键 词：下颌骨 牵引成骨 血管生成 

分 类 号：R782.2[医药卫生—口腔医学]