Figure 4: AGEs and alendronate inhibit different stages of osteoclastogenesis. Raw 264.7 macrophages and UMR106 osteoblastic cells were co-cultured in 6-well plates. BSA or AGEs (100 μg/ml) and/or alendronate (10-5M) were added at different time points: a - from the beginning to the end of an 8-day co-culture; b - from the beginning to the end of a 4-day co-culture; and c – from day 4 to 8 of an 8-day coculture. At the end of all incubations, TRAP activity was determined cell lysates by a colorimetric assay. Results are expressed as % of basal (BSA alone for each time point), and are shown as the mean ± S.E.M. (* p<0.05).