Experimental Bone Mass And Correlation Of Biomechanical Properties With Parathormone In Rats With Glucocorticois-induced Osteoporosis

Objective:To investigate experimental study of bone mass and correlation of biomechanical properties with parathormone in Rats with glucocorticoids-induc-ed osteoporosis, which can support experiment base and theory basis for whether parathormone could arrest glucocorticods-induced osteoporosis.Method:1.60 rats were divided randomly into three groups with various estrogen doses, which named group A and group B and group c. Every group included 20 rats.2. The rats of group B and group C were injected dexamethasone (1mg/kg) for 8 weeks, and 2 times one week. Group A were injected NS for 8 weeks.8 week later, group c were injected parathormone (2ug/d) for 4weeks and group A and group B were injected nothing.3.12 weeks later,16 rats from group A and group B and group C were determined the BMD of lumbar and femur.4. Take B, C three groups on the left tibia 4th lumbar level of 16 was observed under fluorescence microscope in the high-level morphology of trabecular bone, and photography.5. From the B, C three groups of randomly selected femur in 8 cases, one fixed on the computer-controlled electronic universal testing machine specially designed scaffolds (span=17mm), with speeds 2mm/min pressure on the femur, until the appreciation of the femur fracture. Automatic computer printouts of measurements, statistical analysis, comparison B, C model of the femur to the compression performance of the finale.6. Femur model will be the other three groups B, C 8, followed by fixed on the torsion test machine, test applied torque, until the pattern damage, measured style of torque and torsional angle, according to mechanics of materials formulas for each pattern the maximum torsion shear stress, statistical analysis, comparing three groups of anti-reverse performance model.result1. Gross observation:The hormone ethylene propylene modeling of both groups during the three animals died (due to meet the statistical needs, were not completion), group A animals, health, survival after 12 weeks, group A animals, a good mental condition, weight gain, group B animals spirit of the apathetic, significant weight loss in group C animals, the spirit of good, body weight increased significantly compared with group B2.1 Osteoporosis model judgments With the control group (Group A) compared to model group (group B) rats at lumbar spine, tibia BMD was significantly lower (P<0.05)2.2 Parathyroid hormone on the BMD of rats With the model (B) group, PTH group (Group C) rats the lumbar spine and femur BMD values increased significantly (P<0.05).3. Prosperous years Watch:B of the tibia and the first four lumbar trabecular bone arranged sparse, Duocheng twisted tear-shaped, connectivity is poor, reduce the number of apparent trabecular thinning, spacing, widening, similar to group C and group A, bone relatively thick trabeculae, connectivity is good, clear bone matrix, marrow cavity size of the uniform.4. B rat femur diameter was significantly lower than the control group (P<0.05), femur length between the two there was no significant difference. group C rats were significantly higher than the diameter of the femur in group B (P<0.05), femur length between the two there was no significant difference in diameter and length of the femur Jiabing between the two groups no significant difference. Femur axial compression resistance results showed that:compared with the control group, group A, B model group, the maximum load, maximum strain elastic modulus of the maximum stress was very significant decrease (P<0.05), group C compared with group B, maximum load, maximum strain elastic modulus of the maximum stress was very significant increase (P<0.05). Group A and group C maximum load, maximum stress maximum strain elastic modulus (P>0.05), no statistically significant5. The results showed that femoral torsion:comparison with the control group, group A, B model group, the largest maximum torque to reverse the shear stress decreased significantly (P<0.05). Group C and group B comparison, the maximum torque maximum shear stress reversed significantly higher (P<0.05). Group A and group C to reverse the torque maximum shear stress (P>0.05), no statistically significant.Conclusion1. Parathyroid hormone can effectively improve the long-term use of glucocorticoid caused by bone loss, increase bone density and prevention of glucocorticoid-induced osteoporosis caused a significant role.2. Parathyroid hormone can effectively improve the glucocorticoid-induced osteoporosis caused by the anti-compression, bending and torsion performance, and reduce the risk of osteoporotic fracture3. Application of parathyroid hormone injection treatment may become a new effective treatment for glucocorticoid-induced osteoporosis way.