Effects of Alendronate on rabbit osteoclast function

To explain the potent inhibition mechanisms of Alendronate on the rabbit osteoclasts in vitro by means of bone pit formation assay. Bone silces or osteoblasts were preincubated with various concentrations of Alendronate and then co cultured with osteoclasts. The percent inhibition of pit formation was 19.5%( P 0.05)?49.0%( P 0.01) and 74.5%( P 0.01) respectively when bone slices were preincubated with various concentrations of Alendronate (10 -11 ,10 -9 ,10 -7 mol/L). After preincubation of osteoblasts with various concentrations of Alendronate (10 -9 ,10 -7 ,10 -5 mol/L) Alendronate inhibited the osteoclast mediated bone resportion (62.8% ( P 0.01)) only at the highest concentration (10 -5 mol/L). The results showed that Alendronate inhibited osteoclast activity either directly or indirectly through the osteoblast.