Investigation Of The Gene Expression Of IGF-1,TGF-β₁,IL-6 And Biomechanics Of Local Bone Callus In Osteoporotic Fracture Healing

As the prolonged longevity of the population, osteoporosis have become the globally medical social problem. Osteoporosis is characterized by increased susceptibility to fracture because of the increased bone fragility, and osteoporotic fracture can,in turn, further aggravate and/or cause general and local osteoporosis, which fell into a vicious cycle and finally result in the disability of the limb or even the death. Most investigation of the osteoporosis had focused on its etiology, However,the datas of the osteoporotic fracture-its most common and severe complication is lacked, of which mostly were limited in epidemiology and prevention and treatment. Until now , the exact mechanisms of the bone healing remain unclear, but the critical role of many local growth factors such as IGF- I TGF- ~ ~, IL-6 in regulation of the bone healing had been demonstrated. The focus of the investigation was to assess the changes of genie expression of the such growth factors and bioniechanics of the local bone callus in the process of the bone healing of the osteoporotic fracture in ovariectomic female SD rats. The results were in bellow: -7- 1. The Immediate Injury Response, Intramembranous Bone Formation and Chondrogenesis stage in bone healing occurs respectively at 1st, 4th, 9th day after osteoporotic fracture, this was as same as the normal process of bone healing. In the Endochondral Ossification stage, the occurrence of the ossification front at 13th day precedes that of the normal at the 15th day after the osteoporotic fracture. 2. There was no difference of the cellular localization in genie expression between the process of the normal and osteoporotic bone healing by in situ hybridization IGF-I mRNA was located in chondrocytes, osteoblasts and mesenchyrnal cells. TGF- P1 mRNA in mesenchymal cells, chondrocytes and osteoblasts. IL-6 mRNA mainly in osteoblasts. 3. The pattern of the genie expression of IGF-I ~ TGF- P . IL-6mRNA were different respectively in the process of the normal bone healing by dot blot analysis. The expression of IGF-I mRNA rose slowly, and then rose rapidly at fracture day 4, reached a peak at fracture day 9(pO.05), and then dropped slowly to normal level. 4. The pattern of the genie expression of IGF-I .. TGF- P ~. IL-6 mRNA were similar to that of the normal in the process of the osteoporotic bone healing by dot blot analysis, but the level of their expression were higher than that of the normal. The expression of IGF-I mRNA rose rapidly at osteoporotic fracture day 4, reached a higher peak at day 9(pO.O5). The expression of TGF- P 1mRNA is very similar to that of the normal, but the level at every osteoporotic day was slightly higher than that of the normal (p>O.05), and also reached a peak at day 13. IL-6 mRNA processed a slowly rise, reached a higher peak than that of the normal at osteoporotic fracture day 13 (p< -8- 0.05), then dropped rapidly, and remained a higher level at day 28 (p>O.05). 5. There was no obviou...