功能负荷改变对兔髁突软骨中骨形成蛋白-2表达的影响

摘要

目的:探讨功能负荷改变对兔髁突软骨中骨形成蛋白-2(BMP-2)表达的影响.方法:24只青春发育期(约2月龄)新西兰白兔随机分为实验组和对照组4个实验点.实验组用手机均匀磨除兔上下切牙各2mm(每周2次)建立兔功能负荷改变的动物模型,实验2、4、6、8周处死,应用免疫组织化学SABC方法检测髁突软骨中BMP-2的表达,并通过计算阳性细胞数目来探讨BMP-2在不同实验时间点的表达变化情况.结果:对照组兔髁突软骨中从2周到8周BMP-2的表达逐渐增强,实验组4、6、8周髁突软骨中部BMP-2较同龄对照组高表达(P＜0.05);第2周髁突软骨后部表达高于同龄对照组(P＜0.05),第4周组髁突软骨后部与同龄对照组之间无差异(P＞0.05),第6、8周髁突软骨后部较同龄对照组低表达(P＜0.05).结论:BMP-2参与了功能负荷改变所导致的髁突软骨适应性改建活动,中部和后部尤为明显.%Objective: To study the effect of altered functional loading on the expression of bone morphogenetic protein- 2 ( BMP- 2) of condylar cartilage. Methods: Twenty-four adolescence New Zealand white rabbits aged two months, were divided into experimental and control groups randomly. In the experimental group incisors were ground twice a week. In this way the altered functional loading was established in rabbit. The rabbits were sacrificed at the end of 2nd, 4th, 6th, 8th week respectively after the application of the altered loading.The expression of BMP-2 in condylar cartilage was examined by immunohistochemical with SABC and the number of positive cell was used for statistical analysis. Results: In control group, expression of BMP-2 increased from 2nd week to 8th week. Compared with the agematched control group, the expression of BMP-2 in intermediate part of condylar cartilage of the experimental group increased at the end of 4th ,6th and 8th week (P＜0.05). Compared with the age- matched control group, the expression of BMP-2 in posterior part of condylar cartilage of the experimental group decreased at the end of 2nd week(P＜0.05 ).But compared with the age- matched control group, the expression of BMP-2 in posterior part of condylar cartilage of the experimental group decreased at the end of 6th and 8th week (P＜0.05),kept the same level at the end of 4th week (P＞0.05). Conclusion: The BMP-2 take part in the procedure of the abnormal remodeling activities of condylar cartilage in altered functional loading rabbits mode, especially in intermediate and posterior part of condylar cartilage.