兔激素性股骨头坏死中磁共振成像、组织学结果与胰岛素样生长因子-I之间的关系
Relationships among magnetic resonance imaging, histological findings, and IGF-I in steroid-induced osteonecrosis of the femoral head in rabbits.
作者信息
Chen Xing-can, Weng Jian, Chen Xue-qun, Du Ji-zeng, Zhu Miao-ping, Pan Yong-qing, Liu Miao
机构信息
Division of Neurobiology and Physiology, Institute of Neuroscience, School of Medicine, Zhejiang University, Hangzhou 310058, China.
出版信息
J Zhejiang Univ Sci B. 2008 Sep;9(9):739-46. doi: 10.1631/jzus.B0820127.
OBJECTIVE
To study the relationships among magnetic resonance imaging (MRI), histological findings, and insulin-like growth factor-I (IGF-I) in steroid-induced osteonecrosis of the femoral head in rabbits.
METHODS
Thirty rabbits were randomly divided into experimental Group A (n=15) and control Group B (n=15). The 7.5 mg/kg (2 ml) of dexamethasone (DEX) and physiological saline (2 ml) were injected into the right gluteus medius muscle twice at one-week intervals in animals of Groups A and B, respectively. At 4, 8 and 16 weeks after obtaining an MRI, the rabbits were sacrificed and the femoral head from one side was removed for histological study of lacunae empty of osteocytes, subchondral vessels, and size of fat cells under microscopy, and the femoral head from the other side was removed for enzyme-linked immunoadsorbent assay (ELISA) for IGF-I.
RESULTS
At 4, 8 and 16 weeks after treatment, no necrotic lesions were detected in Group B, while they were detected in Group A. Light microscopy revealed that the fat cells of the marrow cavity were enlarged, subchondral vessels were evidently decreased, and empty bone lacunae were clearly increased. The IGF-I levels in Group A were significantly higher than those in Group B. At 8 weeks after the DEX injection, the MRI of all 20 femora showed an inhomogeneous, low signal intensity area in the femoral head, and at 16 weeks, the findings of all 10 femora showed a specific "line-like sign". The MRI findings of all femora in Group B were normal.
CONCLUSION
MRI is a highly sensitive means of diagnosing early experimental osteonecrosis of the femoral head. However, the abnormal marrow tissues appeared later than 4 weeks when the expression of IGF-I increased. This reparative factor has an early and important role in response to steroid-induced osteonecrosis of the femoral head, and provides a theoretical foundation for understanding the pathology and designing new therapies.
目的
研究兔激素性股骨头坏死中磁共振成像（MRI）、组织学表现及胰岛素样生长因子-I（IGF-I）之间的关系。
方法
30只兔随机分为实验组A（n = 15）和对照组B（n = 15）。分别于A组和B组动物的右臀中肌以1周的间隔注射2次7.5 mg/kg（2 ml）地塞米松（DEX）和生理盐水（2 ml）。在获得MRI后的4、8和16周，处死兔子，取一侧股骨头进行显微镜下骨陷窝内无骨细胞、软骨下血管及脂肪细胞大小的组织学研究，另一侧股骨头用于IGF-I的酶联免疫吸附测定（ELISA）。
结果
治疗后4、8和16周，B组未检测到坏死病变，而A组检测到。光镜显示骨髓腔脂肪细胞增大，软骨下血管明显减少，空骨陷窝明显增加。A组IGF-I水平显著高于B组。DEX注射后8周，所有20个股骨头的MRI显示股骨头内不均匀低信号区，16周时，所有10个股骨头的表现显示出特征性的“线状征”。B组所有股骨头的MRI表现均正常。
结论
MRI是诊断早期实验性股骨头坏死的高度敏感方法。然而，异常骨髓组织出现时间晚于4周，此时IGF-I表达增加。这种修复因子在激素性股骨头坏死反应中具有早期且重要的作用，并为理解其病理及设计新疗法提供了理论基础。
Zotero 插件