卵巢切除后骨质疏松大鼠股骨颈质量的力学特征及外展肌群重链肌球蛋白基因的表达

目的 研究卵巢切除术诱导的绝经后骨质疏松症大鼠模型股骨颈质量的力学表达与附着肌群肌强度基因表达的变化,探讨股骨颈骨质疏松性骨折风险升高的肌肉-骨骼机制。方法 将20只8月龄Wistar雌性大鼠随:饥分为对照组(10只,双侧卵巢假切除)和模型组(10只,为双侧卵巢切除)。手术后180 d,分别测定股骨颈质量的结构强度、结构硬度和结构韧性与附着股骨颈的外展肌群肌强度的重链肌球蛋白基因的表达。结果 模型组的结构强度(168.09±25.20)N、结构硬度(682±131)N/mm和结构韧性(0.04±0.07)J与对照组比较都显著下降(P<0.05);附着的外展肌群肌强度的基因表达,对照组重链肌球蛋白ImRNA表达量高,模型组表达量低。结论 股骨颈质量的低结构强度、低结构硬度与低结构韧性的力学表达导致股骨颈骨质疏松性骨折风险升高;附着肌群肌强度的重链肌球蛋白ImRNA低表达对于造成骨质量力学表达变化的骨重建高转换的调控机制具有重要的作用。

Mechanical characteristics of bone quality of the femoral neck and Gene Expression of heavy chain myoglobulin of the attached intensive muscle groups in postmenopausal osteoporotic rat model established by ovariectomy

Objective To study the mechanical expression of femoral neck bone quality and gene expression of the attached muscle strength in postmenopausal osteoporotic rat model established by ovariectomy, and to explore the muscle - bone mechanisms of the increased osteoporotic fracture risk of femoral neck. Method Twenty 8 - month - old female Wistar rats were divided randomly into two groups of the Sham - operated control group (n=10) and Ovariectomy (OVX) group (n= 10) . At 90 days after surgery, the mechanical expression (Max- load, Stiffness and Energy) of femoral neck bone quality based on material test and the gene expression ( MHCI mRNA) of the attached muscle strength based on RT - PCR were detected. Results In mechanical expression, the Max - load, Stiffness and Energy in OVX group were lower than those in Sham - operated control group (P < 0.05). In gene expression , the MHCI mRNA in Sham - operated control group was identified clearly, but that in OVX group the expression was low. Conclusion The lower mechanical expression of femoral neck bone quality is able to induce the increased osteoporosis fracture risk of femoral neck. The lower gene expression of the attached muscle strength has important contribution to the regulation mechanism of high bone remodeling rate which lead to the lower mechanical expression of bone quality. So bones as well as muscles should be covered in the treatment protocol and should be regarded as the clinical strategy in reducing the osteoporosis fracture risk of femoral neck.