渐进性咬合紊乱对幼、成年雌性大鼠髁突软骨中VEGFR-1,2表达的影响

目的：探讨渐进性咬合紊乱对幼年和成年雌性大鼠髁突软骨中血管内皮生长因子受体（VEGFR）1,2表达情况的影响。方法：建立大鼠渐进性咬合紊乱模型,采用免疫组化方法检测髁突软骨中VEGFRs的表达情况,通过计算阳性细胞数的方法,分析大鼠髁突软骨适应性改建过程中VEGFRs的表达变化规律。结果：VEGFR-1,VEGFR-2在大鼠髁突软骨中的分布趋势基本相同,均主要分布在大鼠髁突软骨的肥大层和过渡层,在增殖层少量表达,在纤维层未见到其阳性细胞表达;正常雌性大鼠髁突软骨从7~11周龄VEGFRs表达逐渐增强,11周龄后降低,并保持在一个稳定水平;幼年及成年实验2周组、幼年实验8周组、成年实验6周组VEGFRs阳性细胞数与其同龄对照组相比均无显著差异;幼年实验4周组及6周组,成年实验4周组VEGFRs阳性细胞数分别明显低于其同龄对照组（P〈0.05）,而成年实验8周组则明显高于其同龄对照组（P〈0.05）。结论：VEGFRs参与了大鼠渐进性咬合紊乱所致髁突软骨的改建活动。

Effect of Gradually Created Disordered Occlusion on the Expression of VEGFRs of the Condylar Cartilage in Rats

Objective： To investigate the effect of gradually induced occlusal disorders on the expression of VEGFR -1,2 in condylar cartilage of rats. Methods： A model of gradually induced occlusal disorders in rat was established. The expression of VEGFRs was detected by SABC immunocytochemistry and analyzed by the number of positive cells in condylar cartilage. The data was analyzed using SPSS 11.0 software package. Results： The distribution of VEGFR-1 and VEGFR-2 positive chondrocytes in condylar cartilage showed the same trend. The positive chondrocytes were abundant in the maturative layer and hypertrophic layer, but were few in the proliferative layer, with no positive chondrocytes seen in the fibrous layer. In control group, the number of VEGFRs positive cells increased from 7-week group to 11-week group, and then kept at a stable level. The number of VEGFRs positive cells did not show any difference between the experimental and the control groups in 2-week-young, 8-week-young and 6-week-mature groups, whereas they were significantly lower in 4-week-young, 6-week-young and 4- week-mature experimental groups but were higher in 8-week-mature experimental group, comparing to their age matched control groups （P〈0. 05）. Conclusion： VEGFRs may play an important role in the remodeling of condylar cartilage induced by occlusal disorders.