摘要
目的观察成年期大鼠在下颌持续前导作用下髁突软骨的改建以及超微结构的变化。方法将30只9周龄SD大鼠随机分为实验组和对照组,实验组佩戴上颌斜面导板,对照组不做任何处理,分别在第3、7、14、21、30天处死动物并取材,免疫组织化学染色检测骨形态发生蛋白2(BMP-2)在髁突中的表达及分布,透射电镜观察髁突软骨细胞的超微结构,Micro CT分析髁突骨质的变化。结果与对照组相比,实验组髁突中部和后部软骨增生明显,软骨细胞BMP-2阳性细胞率及灰度值在第7天开始增多,随时间延长而增强,髁突软骨细胞的超微结构出现细胞核固缩,核周微丝变少、脂滴变小、内质网腔隙肿胀、细胞外基质增宽变多等。Micro-CT显示实验组的新生骨和骨小梁厚度、骨小梁数量和分离度随时间延长而增加。结论在下颌持续前导下,成年期大鼠髁突软骨出现增生性改建,并存在BMP-2的高表达。
Objective This study investigated the reconstructed mandibular condylar cartilage and the ultrastructural variations in mandibular condylar cartilage in adult rats as a result of mandibular advancement. Methods Thirty 9-week-old male Sprague-Dawley rats were randomly divided into experimental and control groups. Rats in the experimental group were subjected to mandibular advancement. Rats were sacrificed on days 3, 7, 14, 21, 30. Sections were cut from condyles, and bone morphogenetic protein-2 （BMP-2） expression in condylar cartilage was examined through immunohistochemical analysis. Condylar cartilage samples were harvested, and ultrastructural changes in these samples were observed under Micro-CT and transmission electron microscope. Results Compared with the control group, the experimental group obviously displayed cartilage hyperplasia in the middle and rear of the condyle. Moreover, the number of BMP-2-positive cells in condylar cartilage and the gray value gradually increased in the experimental group on day 7 of the intervention. Ultrastmctural changes, such as karyopyknosis, reduced microfilaments around the nucleus, reduction in size or even disappearance of lipid droplets, swelling of endoplasmic reticulum compartments, broadened and increased extracellular matrix, were observed in the condylar hypertrophic chondrocytes. Micro-CT revealed that the trabecula and the newly formed bone gradually thickenedConclusion Hypertrophic remodeling of the condylar cartilage and high BMP-2 expression are observed in adult rats as a result of continuous mandibular advancement.
出处
《华西口腔医学杂志》
CAS
CSCD
北大核心
2016年第6期632-638,共7页
West China Journal of Stomatology
基金
山东省科技发展项目(2014GSF11804)~~
关键词
髁
软骨
超微结构
骨形态发生蛋白
condyle
cartilage
ultrastructure
bone morphogenetic protein
