血小板衍生生长因子-BB和转化生长因子-β_1联合应用对大鼠正畸牙移动的影响

Effects of local and combined administration of PDGF-BB and TGF-β_1 on orthodontic tooth movement in rats

目的观察局部应用血小板衍生生长因子(PDGF)-BB、转化生长因子(TGF)-β1及两者联合作用对大鼠正畸牙移动的影响。方法选用6～8周龄Wistar雄性大鼠40只,随机分为A组、B组、C组和D组,每组10只。在大鼠上颌左侧第一磨牙与上切牙之间安装一力值50g的正畸装置拉磨牙向近中移动,每隔3d在第一磨牙颊侧牙龈黏膜下注射生长因子0.1ml。A组:联合注射5ngTGF-β1及10ngPDGF-BB,B组:注射10ngPDGF-BB,C组:注射5ngTGF-β1,D组:即对照组注射0.9%氯化钠注射液。每组分别于加力第1,3,7,14天,制作标准模型,测量左上颌第一磨牙的移动距离,加力14d后,处死大鼠,取第一磨牙及其牙周组织,苏木素-伊红(HE)染色观察牙周组织的形态改变、计数压力侧破骨细胞数量。结果实验组大鼠压力侧破骨细胞数在实验过程中明显多于对照组,且实验组大鼠牙齿在加力的7d和14d移动距离大于对照组,PDGF-BB与TGF-β1联合应用有协同效应,其压力侧破骨细胞计数及牙齿移动距离与单一因子组相比差异有统计学意义(P<0.05)。结论应用外源性的PDGF-BB与TGF-β1能增加破骨细胞的产生,同时能显著加快牙齿移动距离,两者联合应用时,具有协同效应,效果更明显。

Objective To investigate the effects of local and combined administration of PDGF-BB and TGF-β1 on orthodontic tooth movement in Wistar rats. Methods Forty male Wistar rats, 6 to 8 weeks of age, were randomly divided into 4 even groups A, B, C and D. In each rat a closedcoil spring delivering a force of 50 g was installed between the first upper left maxillary molar and the upper incisor to move the molar mesially and growth factors were injected every three days in the buccal submucosal area of the molar. In addition, 5 ng of TGF-β1 and 10 ng of PDGF- BB was injected locally in group A, 10 ng of PDGF-BB in group B, 5 ng of TGF-β1 in group C, and physiological saline in group D. The distance of the maxillary left first molar was measured on day 1, 3, 7 and 14 before the rats were sacrificed after the experiment lasted for 14 days. The first molar and its periodontal tissue were harvested for HE staining observation of the morphological changes in the periodontal tissue and counting numbers of osteoclasts at the pressure side. Results In the process of the experiment, the numbers of osteoclasts at the pressure side in the experimental groups were significantly larger than those in the control group. The moving distances of the teeth on days 7 and 14 in the experimental groups were longer than in the control group. Combined application of PDGF-BB and TGF-β1 showed a synergistic effect, for it resulted in significant differences in the osteoclast count at the pressure side and in the tooth moving distance compared with the other 2 single-factor groups （P〈0.05）. Conclusion Local administration of exogenous PDGF-BB and TGF-β1 can increase generation of osteoclasts and at the same time can significantly accelerate tooth movement. Combined application of the two has a more obvious synergistic effect.