The Effect Of Sympathetic Nerve On Physiological Function Of Osteoclasts During Bone Remodeling

Objective:The metabolism of bone has been proved to be affected by the nervous system. Currently a large number of studies have shown that the nervous system, especially the sympathetic nervous system has effect on the bone remodeling. The aim of the experiment was to study the effect of sympathetic nerve on physiological function of osteoclasts during bone remodeling based on the establishment of the rat sympathetic denervation model by surgical method.Materials and methods:1. To establish the rat sympathetic denervation model by surgical excision of the rat unilateral cervical ganglion.2. To establish the tooth socket bone healing model by extracting the rat first maxillary molar in experimental side(sympathetic denervation) and control side (sympathetic innervation).3. TRAP staining and the protein immunohistochemical staining of RANKL and OPG were studied at1,3,7,14and21days postoperatively.Results:1. The data of TRAP staining showed experimental groups had significant less TRAP positive staining cells than control groups at3days,7days and14days time point (P <0.01).2. The results of the protein immunohistochemical staining of RANKL and OPG, showed:(1) There was no significant difference of the OD of RANKL in the experimental group when compared to the control group at1day time point (P>0.05), whereas significant lower expression of RANKL was found in the experiment group compared to control group at3days,7days,14days and21days time points(P <0.01).(2) The OD of OPG increased by the time at both groups. The experimental group showed significant higher expression of OPG than the control group at all time points (P <0.01).(3) At all time points, significant less value of RANKL/OPG was showed in experimental group when compared to the control group (P <0.01).Conclusion:It was concluded that the sympathetic denervation could effectively decrease bone resorption and increase bone formation during bone healing by decreasing the number of osteoclast and inhibiting the activity of osteoclast.