The Effects Of Intermittent Low-dose Administration Of RhPTH(1-34) On Fracture Healing Of Rabbits

Objective: To study the effect of intermittent low-dose administration of rhPTH(1-34) on fracture healing.Methods: A 3 mm gap was performed in right mid-tibials of 50 New Zealand white rabbits.The osteotomy site was stabilized with long plaster cast external fixation.The rabbits were divided randomly into two groups such as A and B group.On the postoperative day,the A group were administrated with rhPTH(1-34) by hypodermic injection,while the B group with NS,3 times a week for 4 weeks.Fracture healing was assessed with X-ray,BMD,BMC test,BMP-2 immunohistochemistry dying.At 4th week of postoperation,histologic analysis was tested with callus and quantity of osteoblast.Results: Callus,the quantity of osteoblast in the A group were more than the B group.There are difference between two groups and intergroup.BMD and BMC at the 2 groups increased along with times,it was much more in the A group than that in the B group at 2,3,4 week(p<0.05,p<0.01).The expression of BMP-2 in the A group higher than it in the B group at 2,3,4 weeks,showing a significant difference(p<0.01) Conclusion: Intermittent low-dose administration of rhPTH(1-34) can obviously promote the fracture healing,accelerat the differentiation of osteoblasts,the mineralization of bone and expression of BMP-2.