Effects of ALN treatment on bone and bone cells. (A) ALN-treated and untreated mice have comparable levels of blood serum osteocalcin as measured by ELISA. Columns represent mean plus or minus SEM; n = 8. (B) ALN treatment has no effect on the number of osteoblasts per field as measured by histomorphometry. (C) Blood serum TRAPCP-5b concentration is reduced in the ALN-treated mice compared with the untreated controls as measured by ELISA. Columns represent mean ± SEM; n = 8. (D) ALN treatment reduces the number of osteoclasts per field as measured by histomorphometry. (E) Representative three-dimensional reconstruction models of tibias from ALN-treated or untreated mice, indicating that in vivo administration of ALN increases the bone mass and alters the bone microarchitecture. ns indicates not significant.