Akhter M P, Jung L K L
Medicine, Creighton University, Suite 4820, 610N, 30th Street, Omaha, NE 68131, USA.
Rheumatology (Oxford). 2007 Aug;46(8):1258-62. doi: 10.1093/rheumatology/kem104. Epub 2007 May 27.
To investigate the nature of osteopenia/osteoporosis in spondyloarthropathy, an inflammatory disorder, using the HLA-B27 transgenic rat model.
HLA-B27 transgenic rats were housed individually and sacrificed at the peak of their disease (8-month-old). The spine and femurs were removed and stored in saline at -20 degrees C until analysis. The bone structure and strength were determined using a micro-computed tomography (micro-CT) device (Scanco Medical) and mechanical testing (Instron 5543). Vertebral bodies and femurs were scanned to determine trabecular structural properties in terms of bone volume (BV/TV), trabecular thickness, and spacing. After scanning, the mid-shaft femurs were subjected to a 3-point bending test (along anterior-posterior direction), the femoral necks were tested in bending, and the vertebral bodies (L4) were tested in compression. Structural (ultimate/yield load, stiffness) and apparent material (ultimate/yield stress, modulus) strength parameters were then determined.
The majority of the bone structural and strength parameters were significantly lower (P < 0.05) in the HLA-B27 transgenic rats as compared with control littermates. Micro-CT data suggested that the transgenic animals had lower BV/TV and trabecular thickness in their vertebral bodies. The poor trabecular structure observed in HLA-B27 rats is also indicative of the poor biomechanical strength properties in the vertebral bodies as well.
The HLA-B27 transgenic rats develop bone fragility similar to that seen in spondyloarthropathy and may be an important model for the study of osteoporosis in spondyloarthropathy.
利用HLA - B27转基因大鼠模型研究脊柱关节炎（一种炎症性疾病）中骨质减少/骨质疏松的本质。
将HLA - B27转基因大鼠单独饲养，并在疾病高峰期（8月龄）处死。取出脊柱和股骨，保存在-20℃的盐水中直至分析。使用微型计算机断层扫描（micro-CT）设备（Scanco Medical）和力学测试（Instron 5543）测定骨结构和强度。扫描椎体和股骨，以确定骨体积（BV/TV）、小梁厚度和间距方面的小梁结构特性。扫描后，对股骨中段进行三点弯曲试验（沿前后方向），对股骨颈进行弯曲试验，对椎体（L4）进行压缩试验。然后确定结构（极限/屈服载荷、刚度）和表观材料（极限/屈服应力、模量）强度参数。
与对照同窝仔鼠相比，HLA - B27转基因大鼠的大多数骨结构和强度参数显著降低（P < 0.05）。Micro-CT数据表明，转基因动物椎体的BV/TV和小梁厚度较低。在HLA - B27大鼠中观察到的不良小梁结构也表明椎体的生物力学强度特性较差。
HLA - B27转基因大鼠发生的骨脆性与脊柱关节炎中所见相似，可能是研究脊柱关节炎中骨质疏松的重要模型。
