Figure 1

A: Measurement of serum calcium levels in OPG-Fc- and huRANKL MAb-treated mice challenged with human RANKL. Young male BDF1 mice (4–5 weeks old) were challenged twice daily (by SC injection, morning and evening) with either PBS (closed squares) or with human RANKL (0.5 mg/kg, closed diamonds) for 6 days. Immediately prior to the first human RANKL challenge, mice were given a single SC injection of either PBS or OPG-Fc (3 mg/kg; open triangle), or huRANKL MAb (1, 3, or 10 mg/kg). Results are expressed as mean ± SE. B: Systemic levels of TRACP-5b in sera of mice challenged with OPG-Fc and huRANKL MAb. 12-week-old female BALB/c mice (n = 5 per group) were given a single subcutaneous injection of PBS, (Vehicle), OPG-Fc (10 mg/kg), or huRANKL MAb (10 mg/kg). TRACP-5b concentration was detected in sera one hour before (baseline) and 72 h after treatment (Mouse TRAP Assay, SBA Sciences). TRACP-5b concentration was significantly different between Vehicle and OPG-Fc treated animals (p < 0.0001). TRACP-5b concentration was not significantly different between Vehicle and huRANKL MAb treated animals (p = 0.1769). Results are expressed as mean ± SE.