SD大鼠髁状突颈部骨折对大鼠髁状突软骨细胞增殖与凋亡的影响

Effect of Unilateral Condylar Neck Fracture on the Proliferation and Apoptosis of Condylar Cartilage Cells in SD Rats

目的研究发育期SD大鼠髁状突颈部骨折对下颌髁状突软骨细胞增殖和凋亡活性的影响.方法18只4周龄SD大鼠,分为髁状突骨折组及空白对照组,分别于术后1周、3周、5周时脱颈处死,取骨折组手术侧、非手术侧及空白对照组髁状突软骨,分别采用免疫组织化学染色和TUNEL染色,观察髁状突软骨细胞中增殖细胞核抗原(PCNA)阳性细胞数和凋亡细胞数.结果在各时间点,手术侧、非手术侧的PCNA阳性细胞数存在统计学差异(P<0.01).术后3、5周,空白组与手术侧PCNA阳性细胞数有统计学差异(P<0.01);术后3周,非手术侧大鼠髁突软骨中凋亡细胞数明显增多,手术侧凋亡细胞数随时间推移明显降低;术后1周,手术侧的凋亡细胞数明显多于非手术侧(P<0.01);术后3周,非手术侧的凋亡细胞数明显多于手术侧(P<0.01);术后1、5周,空白组与手术侧凋亡细胞数有显著性差异(P<0.01).结论一侧髁状突颈部骨折导致两侧髁状突所受应力失衡,影响两侧髁状突软骨细胞增殖与凋亡的平衡,进而影响下颌骨及颌面部的发育.

Objective To investigate the effect of unilateral condylar neck fracture on the proliferation and apoptosis of condylar cartilage cells in SD rats.Methods Eighteen 4 weeks old rats were randomly divided into two groups: experimental group(unilateral condylar neck fracture),and control group(no operation).The rats were killed at 1,3,5 weeks after surgery,condylar cartilages were obtained in the operating side,non-operating side of rats in experimental group and control group.Immunohistochemical staining was used to qualitively examine the PCNA positive cell,TUNEL was chosen to detect the apoptotic cell.Results There was significant difference in PCNA positive cell number between operating side and non-operating side in experimental group at different time(P <0.01).There was significant difference in PCNA positive cell number between operating side and non-operating side in control group at 3 and 5 weeks after surgery.There was significant difference in apoptotic cell number between operating side and non-operating side at 1 and 3 weeks after surgery.There was significant difference in apoptotic cell number between operating side and non-operating side in control group at 1 and 5 weeks after surgery.Conclusion The unbalanced stress caused by unilateral condylar neck fracture breaks the balance of cell proliferation and apoptosis,and affects the development of mandible and oralsurface.