Effects of insulin-like Growth Factor-1(IGF-1) on Bone Formation of Rabbit Osteoblast in vitro

Objective: To investigate the effects of IGF-1 on bone formation of rabbit osteoblast in vitro.Methods:Osteoblasts were obtained from rabbit costal bone by explant culture technique.The second subculture was exposed to IGF-1 at variant concentrations of 0.1,1,10 and 20ng/ml for 24 and 36 hours,and the effects of IGF-1 on osteoblast proliferation was observed by MTT assay.The contents of BGP were measured by the radioimmunoassay in the culture supernatant harvested after the second subculture were exposed to IGF-1 for 72 and 108 hours.Results:Osteoblast exposed to IGF-1 for 24 and 36 hours at variant concentrations of 0.1,1,10,20ng/ml proliferated significantly compared with the control (P0.001),and significant differences were found between every two groups when osteoblast were exposed to IGF-1 at range from 0.1 to 10ng/ml(P0.05).Levels of osteocalcin in culture supernatant of osteoblast exposed to IGF-1 at variant concentrations for 72 and 108 hours was not statistically significant compared with control group (P0.05).Conclusions:IGF-1 could promote the proliferation of osteoblast,and there were dose-dependent relationship at a limited range from 0.1 to 10ng/ml.IGF-1 had no effect on osteocalcin synthesis of osteoblast.