【摘要】 目的　探讨程序化细胞死亡 (programmedcelldeath ,PCD)及bcl 2、Bax基因在颞下颌关节发育中的作用。方法　利用缺口末端转移酶标记法 (tdt mediateddUTPnickendlabeling ,TUNEL法 )、原位杂交检测mRNA技术及免疫组织化学染色分别对SD胎鼠及生后 1周颞下颌关节发育不同时期PCD、bcl 2mRNA及bcl 2、Bax蛋白的表达进行了观察。结果　各时期髁突软骨细胞中均有PCD出现 ,阳性PCD细胞主要分布于软骨增殖层及浅层肥厚层与深层肥厚层交界的区域 ;髁突软骨增殖层及浅肥厚层大部分细胞bcl 2mRNA表达阳性 ,深层肥厚层仅有极少数成熟软骨细胞bcl 2mRNA表达阳性 ;bcl 2蛋白表达的分布与bcl 2mRNA基因的表达部位基本一致 ,进入深层肥厚层减弱、消失 ;Bax则在髁突软骨全层均有明显表达。结论　髁突软骨细胞PCD主要是受内在bcl 2及Bax基因控制 ,PCD的部位及数量取决于bcl 2及Bax表达量的变化。bcl 2可能是维持软骨细胞生命 ,保证软骨细胞增殖、分化和成熟的重要基因之一。更多还原

【Abstract】 Objective To evaluate the roles of bcl 2, bax gene and programmed cell death(PCD) in the TMJ development Methods PCD, expression of both mRNA and protein of bcl 2 and expression of bax protein were observed by Tdt mediated dUTP nick end labeling (TUNEL), mRNA in situ hybridization and immunohistochemical staining in TMJ of SD rats during series prenatal and postnatal developmental periods Results PCD was involved in condylar cartilage in development of different periods The cells of PCD were mainly located in proliferative zone and the area between prehypertrophic zone and late hypertrophic zone bcl 2mRNA was expressed with high levels in proliferative and prehypertrophic zones and very few matured chondrocytes expressed bcl 2 The expression of bcl 2 protein showed the same distribution as bcl 2mRNA, but gradually decreased in late hypertrophic zone, compared with strong expression of Bax throughout condylar cartilage Conclusions PCD of condylar cartilage is regulated by bcl 2 and bax gene, the number and site of PCD are attributed to the change of bcl 2 and bax gene, and bcl 2 is an important gene in maintaining survival of chondrocytes during the proliferation, differentiation and maturation更多还原