The Effects Of Adiponectin On Fracture Healing In Aged Rats

ObjectiveTo investigate the effects of Adiponectin on osteoporotic fracture healing in aged rats.MethodsThe status of osteoporosis in 22-month-old male rats was confirmed by total body bone mineral density measurement. Fracture healing model was established by osteotomy with a wire saw and fixation with a Kirschner pin on left femur.70 model rats were randomized into two groups: 35 for control group, and 35 for Adiponectin group. Adiponectin group was given daily by intraperitoneal injection at dose of 10μg /kg/d for total 10 days, while control group was given an equivalent volume of saline. The rats were scarified in 2, 4, 8 ,12 weeks after operation,the callus formation was monitored by histological and immunohistochemistry(osteoprotegerin OPG) assessment, the bone mineral density measurement of the callus and the right femur was taken, alkaline phosphatase(ALP) activity as an index of bone formation was arrayed. Normal radiographs were taken at 12 weeks. Get the measurement data to mean±standard deviation, the experimental group and the control group were few compared with the two samples of information t test, P <0.05 for the difference statistically significant.Results1.The histomorphological analysis revealed that the process of cartilage forming and transforming were postponed in Adiponectin group. The immunohistochemical results showed a decrease of expression of OPG in Adiponectin group.2. Adiponectin group had lower bone mineral density.3. Adiponectin produced a significant decrease in serum ALP.4. Normal radiographs showed Adiponectin group had less callus formation.ConclusionAdiponectin delays the osteoporotic fracture healing in aged rats. The most contributing factor associated with the poor fracture healing was inhibition of OPG.