Study On The Relationship Between Fracture Healing And The Expression Of Osteoprotegerin And Its Ligand In Vivo Of Type2Diabetes Rats

Objective:To establish the model of type2diabetes of rats and investigate the relationship between impaired fracture healing and the change of the expression of OPG and its ligand in vivo in type2diabetes ratsMethods:20physical fitness male Sprague-Dawley rats were divided into control group (10rats) fed with normal diet and experimental group (10rats) fed with high fat and sucrosum diet.4weeks later, we individually intraperitoneally injected rats with streptozotocin(35mg/kg) or citrate buffer solution.2weeks later, we chose the rats which fasting blood sugar exceeded16.7mmol/L into experimental group. Onwards, we established the model of distraction osteogenesis in the left tibiae of all the rats. Distraction was initiated the following day at0.15mm b.i.d. and continued for14days. At the beginning of15day, we sacrificed all the rats and collected the blood and left tibiae. Both femora were harvested with germ free. We tested blood glucose、triglyceride、total cholesterol and serum insulin of blood collected at different time points. We observed callus formation in distraction gap by X ray and the formation of primary matrix front and microcolumn formation by histological examination. Will preserve a good tibial specimens, respectively, to do chemical analysis of immunohistochemistry and real time quantitative nucleic acid amplification detection system (Real-time Quantitative PCR, Detecting System, QPCR) Check.Results:After4weeks, the measured experimental group, serum insulin, triglycerides and total cholesterol than the control group increased (P<0.01), fasting plasma glucose was not significantly different (P>0.05). Six weeks after the end of the experiment, the experimental group, triglycerides, total cholesterol and fasting plasma glucose compared with the control group increased (P<0.01), serum insulin was no significant difference (P>0.05). HE staining of the bone tissue:the experimental group and control group micro-bone column shortened and disorganized, and the initial matrix forefront of most of the light dye. X-ray demonstrated that the experimental group and control group significantly reduced the formation of callus between the fracture fragments; immunohistochemistry and QPCR test results show that the experimental group than the control group callus OPG expression decreased (P<0.01), osteoprotegerin ligand expression increased (P <0.01), both as anti-correlation (P<0.01).Conclusion:Bone formation in fracture callus was impaired in type2diabetic rats. OPG was decreased and osteoprotegerin ligand was increased in bone tissue in diadetic rats, which may lead to impaired bone formation in type2diabetic rats.