激素性兔股骨头坏死骨形态学及细胞凋亡变化

Changes of bone structrue and apoptosis in rabbits with steroid-induced necrosis of femoral head

目的探讨糖皮质激素性兔股骨头坏死骨形态学改变及细胞凋亡变化。方法成年健康新西兰大白兔30只,雌雄不限,随机分为两组,每组15只。空白对照组(N组),单纯标准饲料及草料喂养,每天肌注等量生理盐水。制模组(M组),喂养同N组,每天地塞米松肌肉注射2.5mg/kg。于实验前及实验后2、4、6、8、10、12周行双侧髋关节X检查,分批处死后行骨组织形态学检查及细胞凋亡分析。结果与N组比较,M组实验第6周开始X线及光镜表现,股骨头骨质疏松,皮质变薄,骨小梁模糊,软骨陷窝增多,髓内血管可见脂栓或血栓形成。TEM显示,骨细胞皱缩变形,透亮带形成。实验第12周,可见不同程度软骨面塌陷,延续到实验终点。与N组比较,M组实验第6周开始凋亡指数(AI)显著升高。结论激素性兔股骨头坏死从实验第6周开始出现显著的病理性骨形态学改变及细胞凋亡变化,而且逐渐加重。

Purpose To observe the changes of the bone structrue and the apoptosis in rabbits with steroid-induced osteonecrosis of the femoral head （ONFH）.Methods 30 New Zealand adult rabbits were randomly divided into 2 groups.In group N,15 rabbits were subjected to the intramuscular injection of saline only and served as control group.In group M,15 rabbits received the intramuscular injection of dexamethasone 2.5 mg/kg×d and served as a model group.X-ray changes of both hips were measured before and at intervals 4,6,8,10 and 12 weeks after experiment.All animals were sacrificed at intervals 4,6,8,10 and 12 weeks.The histopathological changes of the femoral head of rabbits were observed under light microscope and TEM,and apoptosis was analyzed.Results Compared with Group N,under x-ray and light microscope,the trabculae of femoral head in Group M became thinner and less solid,there were obviously more bone lacunae and fat embolism or thrombus in the bone marrow vessel from sixth week of the experiment.Femoral heads in Group M showed subchondral bone necrosis with structural disorganization under TEM in the end of experiment.The apoptesis index in Group M was sigificantly higher then that in Group N from sith week.Conclusion The pathological changes of the bone structure and apoptesis are observed from the sixth week of the experiment with progressive exacerbation.