Experimental osteoinduction by recombinant human bone morphogeneticprotein 2 in tissue with low blood flow: a study in rats

We have compared osteoinduction in soft tissues by 0, 2, 10, and 50 mg of recombinant human bone morphogenetic protein-2 (rhBMP-2) in Wistar rats with a surgically compromised blood supply and controls with a normal blood supply (n = 5 in each group). Three weeks later in the radiographic evaluation, the volume of bone formation in the low-blood-flow groups was similar to that in the controls, and was dependent on the concentration of implanted rhBMP-2. On histological evaluation much woven bone was noted in the low-blood-flow groups, but the volume of bone was less than in the controls. Alkaline phosphatase activity was less and calcium content in the low-blood-flow groups were also less than in the control rats. However, their values increased dose-dependently with implanted rhBMP-2. These results suggest that the osteoinducting activity of rhBMP-2 is reduced in tissues with a low blood supply, but higher doses of rhBMP-2 can be used in compromised tissue.