Effects of NO donor on the proliferation differentiation and expression of bone morphogenetic protein-2 in rat osteoblasts

Objective:To study the effects of nitric oxide(NO) on the proliferation differentiation and expression of bone morphogenetic protein-2(BMP-2) in rat osteoblasts.Methods: Osteoblasts were isolated from calvarial bone of SD rats by combined means of enzymatic digestion and fragments.Then the cultured cells were added in NOC-18 of concentration in 0,1,10,100 umol,and the cell proliferation was measured by thiazoly blue(MTT) assay.The protein expression of BMP-2 was determined by immunocytochemisty.Results: NOC-18 had significant proliferation effect on osteoblasts and all the expression of osteoblasts BMP-2 were increased.Among the 3 groups,the group with NOC-18 10 umol had the strongest osteoblast proliferation.Conclusion: NO had dual effects on proliferaton and differentiation in rat osteoblasts.Moderate low concentration of NO could stimulate proliferation and differentiation of osteoblast and increase bone formation;high concentration of NO had weak effects on stimulating proliferation and differentiation of osteoblast,even inhibiting osteoblasts differentiation.The results showed that the effects of NO in osteoblast was correlated with the expression of BMP-2.