Preliminary Study Of The Effect Of Propranolol On Bone Metabolism

Objective The aim of this study was to demonstrate the effection of propranolol on the proliferation and expression of OPG/RANKL in rabbit osteoblasts and on osteoclasts,then to explore its possible mechanism on bone metabolism.Materials and methods 1.Rabbit bone marrow mesenchymal stem cells(BMSCs)were extracted and cultured in vitro.BMSCs were induced into osteoblasts,ALPstaining and alizarin red staining were used to identify the osteoblasts 2.Taking rabbit osteoblasts as in vitro experimental model,using different concentrations of propranolol(10-2?mol/ml,10-3?mol/ml,10-4?mol/ml)to stimulate the rabbit osteoblasts respectively.And then the MTT method was used to detect its influence on osteoblast proliferation,reverse transcriotion-polymerase chain reaction(RT-PCR)method to detect the expression of OPG and RANKL m RNA on the osteoblasts,Enzyme-linked immunosorbent assay(ELISA)to detect the protein content of OPG and RANKL on the supernatant fluid.3.rabbit osteoclasts were cultured,in the nutrient solution with different concentrations of propranolol(10-2?mol/ml,10-3?mol/ml,10-4?mol/ml)for 72 hours respectively.And then the tartrate-resistant acid phosphatase(TRAP)and Toluidine Blue staining were used to detect its effect on osteoclast.Result1.BMSCs were induced into osteoblasts demonstrated by ALP staining and alizarin red staining;2.Compared with control group,different concentrations of propranolol increased OD value after treated for 48 h and 72 h,indicating it can promote the proliferation of osteoblast after treated for 48 h and 72 h,while after 96 h the OD value were lower than control group;the OD value were biggest,when propranolol was 10-3?mol/ml in 48 h and 72 h.3.The results of ELISA and RT-PCR both showed that the content of OPG were higher than that of control group when the propranolol effected on osteoblasts after 72 h,while the content of RANKL was contrary,resulting in the ratio of OPG/RANKL in the experimental group were higher than those of control group.4.compared with the control group,10-2?mol/ml,10-3?mol/ml,10-4?mol/ml group of propranolol were able to make the number of osteoclasts and bone resorption area decreased(P < 0.05).ConclusionPropranolol can promote osteoblast proliferation within a certain time.And by increasing the expression of OPG and inhibiting the expression of RANKL in osteoblasts,resulting increasing the OPG/RANKL ratio to promote osteoblast proliferation and inhibit osteoclast differentiation,propranolol have a potential of regulating bone formation and bone resorption.