导下颌向前对生长期大鼠髁突软骨结缔组织生长因子表达的影响

Expression of Connective Tissue Growth Factor in Rat Mandibular Condylar Cartilage Following Function Mandibular Forward Positioning

目的:通过建立导下颌向前的Sprague-Dawley(SD)大鼠的动物模型进行免疫组化实验,观察结缔组织生长因子(CTGF)在髁突软骨中分布的变化,探讨CTGF对前伸下颌后的髁突软骨的影响。方法:建立SD大鼠动物模型,选取45只5周龄SD雌性大鼠,体重约100g,随机分为对照组(20只)和实验组(25)只,组内再随机平均分为5组(3、7、14、21和30d)。实验组动物24h佩戴改良可摘式上颌斜面导板矫治器,对照组动物不做处理。免疫组化染色标记CTGF,观察髁突软骨各层CTGF的表达变化。对CTGF的阳性表达量进行半定量分析。结果:对照组和实验组中髁突软骨组织中均有CTGF的表达,主要分布于肥大层和增殖层。实验组不同时间点髁突肥大层和增殖层中CTGF的平均光密度值分别高于对照组的平均光密度值(P<0.05)。与对照组相比,实验组7d后髁突肥大层和增殖层中CTGF的表达开始上升,到第14天达到最高,之后CTGF表达回落,但仍高于对照组(P<0.05)。实验3d、30d,肥大层和增殖层中CTGF实验组与对照组相比无统计学差异。结论:CTGF可能参与了功能负荷改变所导致的髁突软骨适应性改建活动。

Objective：To investigate the expression of connective tissue growth factor（CTGF）in rat mandibular condylar cartilage during functional mandibular forward positioning with immunohistochemical staining.Methods：45five-week-old female Sprague-Dawley（SD）rats were randomly divided into five experimental groups（n=25）and five control groups（n=20）.The animals in the experimental groups were fitted with modified removable acrylic inclined planes to advance the mandible,while rats in the normal control groups were left intact.The rats were sacrificed on day 3,7,14,21,and 30,respectively,to assess the expression of CTGF with immunohistochemical staining.Results：When compared with the proliferative zone of the same age in the control and experimental groups,higher expression of CTGF was observed in the hypertrophic zone of posterior part of condylar cartilage（P〈0.05）.The expression of CTGF in the proliferative zone of posterior part of condylar cartilage in the control groups did not show significant differences during the experiment period,and the hypertrophic zone displayed the same pattern.However,compared with those of the age-matched controls,the positive signals of CTGF in the proliferative zone and hypertrophic zone of the experimental animals were significantly stronger on day 7,14,and 21,respectively（P〈0.05）,whereas no statistical differences were found on days 3and 30.Conclusion：CTGF expression in mandibular condylar cartilage is induced by the mechanical compressive stimuli in vivo.As a cytokine,CTGF may mediate the morphological changes induced by mechanical stimuli in condylar cartilage.