中文摘要：

目的：探讨在SD大鼠下颌骨临界性骨缺损（critical size bone defect，CSD）与自愈性骨缺损修复过程中，各时相点干细胞因子（stem cell factor．SCF）的表达情况。方法：①分别在36只SD大鼠双侧下颌骨的下颌角部制造临界性骨缺损f直径5mm）和自愈性骨缺损（直径2mm）模型，实验动物分为6组，在术后第1、3、5、7、14、21天分别处死；②利用免疫组织化学方法检测骨缺损区各时相点SCF的表达情况；③利用Western印迹法检测骨缺损区各时相点SCF存在与否．并进行半定量分析。结果：成功构建了大鼠双侧下颌骨的临界性骨缺损和自愈性骨缺损模型。免疫组织化学结果显示．骨缺损愈合的各时相点SCF均有较高的表达，但SCF在临界性骨缺损组各时相点的表达，均低于自愈性骨缺损组。结论：SCF在骨缺损修复中发挥重要的作用。

英文摘要：

Objective： The current paper was aimed to detect the expression of stem cell factor （SCF） during the repair process of rats＇ mandibular defects. Methods： 36 SD rats were used in this study. In one side of the mandible , critical size bone defect （CSD） in 5 mm dimension was established. A self-healing bone defect in 2 mm dimension was created in the contralateral side of the mandible. Animals were randomly divided into 6 groups and sacrificed on 1, 3, 5, 7, 14, 21 d after surgery respectively. Expression of SCF during the regeneration process were determined by immunohistochemistry and Western blot. Data were expressed as x±s by SPSS 13.0 software. We used Student＇s t test to determine the significance of difference between groups. Significance was set at P〈0.05. Results： The expression of SCF genes was detected in both groups at all times, and expression of SCF in CSD group was weaker than those in self-healing bone defect group at the same time （P〈0.05）. The results of western blot also confirmed the results by immunohistochemistry. Conclusion： SCF plays an important role in bone defect repair.