机械牵张力对大鼠前腭缝组织学结构的影响

Effects of mechanical tension on the histological structure of anterior palatine suture in rats

目的研究扩弓簧机械牵张力作用后大鼠前腭缝的组织结构变化。方法将30只健康雄性SD大鼠随机分为空白组(15只)和扩弓组(15只),每组随机分为3个小组(每小组5只),分别于扩弓后第1、4、7天处死。分离大鼠上颌骨,取前腭缝组织进行HE、Masson及免疫组织化学染色,观察两组大鼠前腭缝组织形态及BMP-2的表达。结果HE及Masson染色显示,扩弓后大鼠前腭缝中间层胶原纤维增多且被拉伸,有新生血管。扩弓第4天出现指状和丛状新生骨,与胶原纤维方向一致,新生骨周围有大量成骨细胞聚集。BMP-2随着扩弓时间的延长表达增强,各时间点表达强度均大于空白组(均P<0.05)。结论机械牵张力作用可使大鼠前腭缝成骨细胞活跃,促进胶原纤维及血管生成,增强BMP-2的表达,促进新骨形成。

Objective To study the histological structure changes of the anterior palatine suture of rats under mechanical tension of expansion spring.Methods Thirty healthy male SD rats were randomly divided into blank group(15 rats)and dilation group(15 rats).The rats in each group were randomly divided into 3 little groups(5 in each little group).Three little groups of rats were killed on the 1st,4th and 7th day of the expansion,respectively.The quilted tissue was taken for HE,Masson and immunohistochemical staining.The morphology of anterior palatine suture and the expression of BMP-2 were observed.Results HE and Masson staining showed that the collagen fibers in the middle layer of anterior palatine suture were increased and stretched,and there were new blood vessels.On the 4th day of expansion,finger-like and plexiform new bone appeared,which was consistent with the direction of collagen fibers.There was a large amount of osteoblasts around the new bone.The expression of BMP-2 increased with the extension of the expansion time,and the expression intensity in each little group was greater than that of blank group(all P<0.05).Conclusion Mechanical tension could activate anterior palatine suture osteoblasts,promote collagen fibers formation and angiogenesis,enhance expression of BMP-2,and promote formation of new bone.