局部注射VEGF对大鼠正畸牙齿移动的影响

目的：观察局部注射重组鼠的血管内皮生长因子(rrVEGF)对大鼠正畸牙齿移动的影响，探讨VEGF在正畸牙齿移动中的作用机制。方法：45只雄性SD大鼠，牵引其上颌第一磨牙近中移动，实验中分别将rrVEGF及生理盐水注射入实验组及对照组大鼠右侧上颌第一磨牙腭侧的骨粘膜下，于实验前3天开始注射，每3天一次。分别在加力l、3、7、14、2l天后记录上颌第一磨牙移动距离。然后将各组动物处死，用HE染色观察牙周组织变化情况并采用免疫组织化学方法对组织中表达的VEGF进行分析。结果：实验组大鼠压力侧破骨细胞教和成骨细胞数在实验全过程中均多于对照组，而且，实验组大鼠牙齿移动距离明显大于对照组。结论：进一步证实VEGF作为旁分泌因子，参与了牙齿移动过程中的牙周组织改建，内源性VEGF和注射VEGF都使牙齿移动量显著增加。因此，VEGF在正畸牙齿移动的机制中具有重要意义。

Effects of local injection of VEGF in the periodontal tissues of rats during orthodontic tooth movement

Objective To investigate the effects of local injection of rrVEGF in the periodontal tissues of rats during orthodontic tooth movement. Methods Orthodontic tooth movement of upper first molar was performed in 45 male Sprague-Dawley rats with coil spring. rrVEGF was injected into the palatal submucosal area adjacent to the right upper first molar 3 days prior to the use of the appliance in experimental group.In control group,same amount of PBS was injected into the same area around the right upper first molar.The injection was applied every third day.The rats were killed after 1,3,7,14, 21 days respectively.After the rats were sacrificed, the distance of the tooth movement was measured.Sections were stained and the expression of VEGF was detected by HE-stain and immunostaining. Results The number of osteoclasts and osteoblasts were enhanced by the injection of recombinant rat VEGF (rrVEGF) with the application of mechanical force for experimental tooth movement.Moreover,the rate of tooth movement was significantly increased in the rrVEGF injection groups compared with the control. Conclusion These results suggested that VEGF,participate in the remodeling of periodontal tissue during orthodontic tooth movement by enhancing the number of osteoclasts as a paracrine factor,and that the amount of tooth movement is accelerated by both endogenous VEGF and injected rrVEGF.So,VEGF plays a key role in orthodontic tooth movement.