激素致股骨头骨细胞坏死、凋亡及对bcl-2表达影响的实验研究

目的：探讨激素性股骨头坏死的发病机制。方法：选用健康成年大白鼠30只，体重约200g，随机分为实验组(冲击注射地塞米松)和对照组。实验8周处死动物，取股骨头作骨细胞组织病理学、超微结构观察，并用TUNEL及免疫组化技术分别检测骨细胞凋亡和bcl-2表达情况。结果：光镜下实验组较对照组股骨头骨小梁变细、稀疏、空骨陷窝明显增多，脂肪细胞增大。电镜下实验组骨细胞体积缩小，核固缩，线粒体及高尔基体肿胀，染色质边聚较多见。实验组凋亡骨细胞增多，bcl-2表达骨细胞轻度增加。结论：激素性股骨头坏死是骨细胞凋亡和坏死共同作用的结果。

Study of necrosis and apoptosis of osteocytes in steroid-induced osteonecrosis of the femoral head

Objective:To observe necrosis,apoptosis and the expression of bcl-2 protein of osteocytes in dexamethasone(DEX)-induced osteonecrosis of the femoral head (ONFH) in rats and study the pathogenesis of the DEX-induced ONFH.Methods:Thirty healthy mature white rats,weighted about 200 g,were selected without sexual restriction and randomly divided into experimental group (injected with massive dose of DEX)and control group.Pathological changes,apoptosis and the expression of bcl-2 protein of the femoral heads were observed in 8 weeks.Results:The trabecula of femoral head of the experimental group changed to thinner and more sparse,empty bone lacune increased,the bone marrow cavity with edema and larger fatty cells were also observed and compared with the control group.Under electron microscope,experimental group showed a great deal of necrotic osteocytes with pyknotic nucleus,the cytoplasm and organell were swelling.Apoptosis and the expression of bcl-2 protein in experimental group were more than that of control group.Conclusion:Necrosis and apoptosis of osteocytes are coagents of the steroid-induced osteonecrosis of the femoral head.