RESUMO
BACKGROUND: Osteogenic ability of bone morphogenetic protein-2 has been wel documented in many experiments, but a series of factors are involved in osteogenesis induction that is a complex network adjustment process. OBJECTIVE: To quantitatively determine the level of insulin-like growth factor I during the lumbar spinal fusion of rabbits induced by recombinant human bone morphogenetic protein-2. METHODS: Sixty adult male New Zealand white rabbits were randomly divided into three groups: bone autograft, bone al ograft or composite bone (bone al ograft with 75 μg recombinant human bone morphogenetic protein-2) was implanted into the L5-6 intertransverse process of rabbits, respectively. At days 7, 14, 21, 28, 35 after implantation, formed cal us was taken to detect the expression of insulin-like growth factor I using real-time fluorescence quantitative PCR. RESULTS AND CONCLUSION: In the three groups, the expression of insulin-like growth factor I gradual y increased with implantation time, peaked at 28 days and then decreased. At 7 days after implantation, the expression of insulin-like growth factor I was higher in the autograft group than the composite and al ograft groups (P < 0.05); at 14 days, the expression of insulin-like growth factor I was higher in the autograft and composite groups than the al ograft group (P < 0.05); at 21, 28 and 35 days, the expression of insulin-like growth factor I was higher in the composite group than the autograft and al ograft groups (P < 0.05). These findings indicate that recombinant human bone morphogenetic protein-2 can improve the expression of insulin-like growth factor I effectively during the lumbar spinal fusion.