Effect of exogenous recombined human bone morphogenetic protein-2 on cell proliferation in lumbar spinal fusion in a rabbit model

Abstract

Objective To explore the effects of exogenous recombined human bone morphogenetic protein-2(rhBMP-2)on cell proliferation in posterolateral lumbar spinal fusion in a rabbit model. Methods Forty-five rabbits that had received posterior graft fusion of transverse process of lumbar vertebra were randomly divided into 3 groups: rhBMP-2/allograft composite group, autologous iliac crest bone graft group, and allograft group. The proliferations of marrow stromal cells (MSCs), osteoblasts and vascular endothelial cells were detected at different times by flow cytometry. Results The numbers of MSCs in the rhBMP-2/allograft composite group at the 2nd, 7th, 35th days after graft transplantation were significantly greater than in the autologous iliac crest bone graft group and allograft group (P 0.05) except at the 2nd day (P=0.028). The quantity of osteoblasts in composite group was significantly larger than in the allograft group at all time points (P<0.05) . The quantities of vascular endothelial cells in the composite group at the 2nd, 7th, 28th days after operation were significantly larger than in the autologous iliac crest bonegraft group (P<0.05). Conclusion The exogenous rhBMP-2 may have a promoting effect on proliferation of MSCs, osteoblasts, vascular endothelial cells at different times during the spinal graft fusion. Key words: Bone morphogcnetic protein; Spinal fusion; Bone transplantation; Cell proliferation