Effects Of Endocannabinoids On Osteoporosis In Ovariectomized Rat Model

Background: With the development of our social and the improvement of the medical technology, people enjoy their lives much longer than before.However, it creates an aging population and many problems , which prompts people to pay more attention on the quality of their lives .On that condition,some diseases like Osteoporosis,which is becoming a common problem in our lives, attracts our attentions.How to prevent osteoporosis is very important. Recently,many researches showed that there were cannabinoid receptors in bone.When the gene of CB recepotor was knocked out ,the activity of osteoblast and osteoclast changed,showed that CB receptor ,CB ligand,CB agonists and antagonist can influence the bone mass and bone remodelling together by regulating the osteoblast and osteoclast's action.In our research,we to observed the influence of CB2 agonist on bone remodeling and bone mass,and explored the mechanisms.Objective: To explore the effect and endocannabinoids on osteoporosis in ovariectomized rat model.Methods: SPF rats,180-200g,were divided into 4 groups randomly:CON group, OVX group , HU308 group , AEA group. CON group suffered a sham operation ,the other 3 groups suffered ovariectomy,3 days later, HU308 group received intraperitoneal injection of CB2 agonists(HU3080.2mg/kg/d),AEA group received intraperitoneal injection AEA (0.2mg/ kg /d).Then,he BMD of the femur and whole body were detected, the right femur was monitored by biomechanics experiment of three-point bending test;after the decalcification,the right femur were cut into paraffin sectionsparaffin sectionparaffin section,and were Observed changes in bone microarchitecturevia HE staining; Collect the plasma to detect the activity of TRAP.Results:1. TRAP:the contents in HU308 group was much lower than other groups; there was no significant differences between AEA group and OVX group;in OVX group,it was higher than other three groups,otherwise ,the content on the time pot of 6 week was lower than on 3 week.2.HE: Compared with OVX and AEA groups,the trabecular loss in HU308 group was at a lower degree , but was higher than group CON.3. Bone biomechanics and BMD:In HU308group ,the bone strength and BMD were higher than those in OVX and AEA groups.there was no significant differences between AEA and CON groups. Conclusion:1.Suffered from ovariectomy can accelerate bone losing in rats.2.CB2 agonist can influence bone mass and bone microstructure by regulating the activity of the osteoclast.3.Endocannabinoid AEA has little influence on bone mass.