Ovariectomy increased bone formation and arthritis increased bone resorption and cartilage destruction. (a) Ovariectomy (OVX) increased bone formation. Serum levels of osteocalcin were analyzed by immunoradiometric assay. (b) Arthritis increased bone resorption. Serum levels of RatLaps were analyzed by ELISA. For controls, n = 10 for sham (open boxes) and ovariectomy (filled boxes); for immunized mice, n = 18 for sham and n = 15 for ovariectomy. (c) Arthritis increased cartilage destruction. Serum levels of cartilage oligomeric matrix protein (COMP) were analyzed by ELISA. For controls, n = 9 for sham (open boxes) and n = 10 for ovariectomy (filled boxes); for immunized mice, n = 17 for sham and n = 14 for ovariectomy. **P < 0.01, ***P < 0.001. Results are shown as box plots (values are given as medians (horizontal lines), interquartile ranges (box) and ranges (whiskers), circles represent outliers).