合并中枢神经损伤骨折愈合过程中胰岛素样生长因子Ⅰ的作用

Role of insulin-like growth factor-Ⅰ in the healing of fracture complicated by central nervous system injury

背景:胰岛素样生长因子Ⅰ由成骨细胞合成,并对成骨细胞具有促进增殖和分化作用。目的:观察中枢神经损伤对胰岛素样生长因子Ⅰ在血清、局部骨痂的表达及骨折愈合的影响。方法:取Wistar大鼠随机分成正常对照组、脑损伤-骨折组、脊髓损伤-骨折组、单纯骨折组。于术后第1,2,3周测量血清中胰岛素样生长因子Ⅰ水平;术后第2,3周行X射线摄片评估骨痂愈合情况,术后1,2,3,4周取股骨制作标本,测量骨痂体积,术后3d,1,2周免疫组织化学染色法检测骨痂局部胰岛素样生长因子Ⅰ的表达。结果与结论:正常对照组、单纯骨折组的胰岛素样生长因子Ⅰ血清质量浓度无明显变化,脑损伤-骨折组和脊髓损伤-骨折组骨痂体积、X射线评分高于单纯骨折组(P<0.05);伤后3d,1,2周时,脑损伤-骨折组和脊髓损伤-骨折组胰岛素样生长因子Ⅰ的血清质量浓度较其他两组明显增加(P<0.01);伤后1周,脑损伤-骨折组和脊髓损伤-骨折组骨折端平均阳性细胞数高于单纯骨折组(P<0.01)。提示中枢神经损伤可以影响血清中胰岛素样生长因子Ⅰ的质量浓度和骨痂局部的表达,从而能促进骨折愈合。

BACKGROUND：Insulin-like growth factor-Ⅰ（IGF-Ⅰ）is synthesized by osteoblasts and has promotive effects on osteoblast proliferation and differentiation.OBJECTIVE：To study the effect of central nerves system injury on expression of IGF-Ⅰ in blood serum,bony callus and fracture healing.METHODS：Wistar rats were randomly divided into 4 groups：normal control group;simple fracture group;brain injury-fracture group;and spinal cord injury-fracture group.The level of IGF-Ⅰ in serum was measured at 1,2 and 3 weeks after operation.Bony callus healing was evaluated by X-ray films at 2 and 3 weeks after operation.The femur was harvested at 1,2,3 and 4 weeks to measure the bony callus volume.The local expression of IGF-Ⅰin fracture sites were determined by immunohistochemical staining at 3 days,1 and 2 weeks after operation.RESULTS AND CONCLUSION：The serum IGF-Ⅰ in the normal group and simple fracture group was not changed greatly,but the bone callus volume and X-ray film grades of the brain injury-fracture group and spinal cord injury-fracture group were larger than those in the simple fracture group（P 0.05）.The concentrations of IGF-Ⅰ in the brain injury-fracture group and spinal cord injury-fracture group were increased significantly than those of other two groups at 3 days,1 and 2 weeks after operation（P 0.01）;the count of positive cells in the brain injury-fracture group and spinal cord injury-fracture group were increased significantly than those of other two groups at 1 week after operation（P 0.01）.The central nervous injuries can increase the concentration of IGF-Ⅰ in blood serum and expression of bony callus,therefore,accelerates fracture healing in rats.