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Treatment with the cathepsin K (CatK) inhibitor odanacatib (ODN) protects against bone loss and maintains normal biomechanical properties in the spine and hip of ovariectomized (OVX) preclinical models. Here, we characterized the effects of ODN on the dynamics of cortical modeling and remodeling, and dimension and strength of the central femur in adult OVX-rhesus monkeys. Animals were treated with vehicle or ODN (6 or 30 mg/kg, once per day [q.d., p.o.]) in prevention mode for 21 months. Calcein and tetracycline double-labeling were given at 12 and 21 months, and the femoral cross-sections were subjected to dynamic histomorphometric and cement line analyses. ODN treatment significantly increased periosteal and endocortical bone formation (BFR/BS), accompanied with an increase in endocortical mineralizing surface (102%, p < 0.01) with the 6 mg/kg dose. ODN at both doses reduced remodeling hemiosteon numbers by 51% and 66% (p < 0.05), respectively, and ODN 30 mg/kg numerically reduced activation frequency without affecting wall thickness. On the same endocortical surface, ODN increased all modeling-based parameters, while reducing intracortical remodeling, consistent with the observed no treatment effects on cortical porosity. ODN 30 mg/kg markedly increased cortical thickness (CtTh, p < 0.001) and reduced marrow area (p < 0.01). Lastly, ODN treatment increased femoral structural strength (p < 0.001). Peak load was positively correlated with the increases in bone mineral content (BMC) (r 2 ¼ 0.9057, p < 0.0001) and CtTh (r 2 ¼ 0.6866, p < 0.0001). Taken together, by reducing cortical remodeling-based and stimulating modeling-based bone formation, ODN significantly improved cortical dimension and strength in OVX monkeys. This novel mechanism of CatK inhibition in stimulating cortical formation suggests that ODN represents a novel therapeutic approach for the treatment of osteoporosis.

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Intraperitoneal injection of lipopolysaccharide (LPS) was used to elicit a sublethal, shock-like condition in mice. LPS, 2.5 mg/kg i.p., induced hypothermia, elevated serum TNF-alpha levels and lethality over a 48 h period in male CD-1 mice. The 5-lipoxygenase (LO) inhibitors, WY-50,295 tromethamine and zileuton (100 mg/kg p.o), significantly inhibited hypothermia at 4, 24 and 48 h after LPS. Interestingly, whereas cyclooxygenase (CO) inhibitors (ibuprofen, etodolac, naproxen and tenidap) at 40-80 mg/kg p.o. stimulated hypothermia at 4 h, they significantly reduced the later stages of hypothermia at 24-48 h. Rolipram (PDE-IV inhibitor) and dexamethasone significantly reduced hypothermia at 4-24 h and 1-24 h, respectively. All the anti-inflammatory agents significantly reduced elevated TNF-alpha levels at approximately 70 min post-LPS, except for ibuprofen. In conclusion, these anti-inflammatory standards indicate that LPS-induced shock involves multiple lipid mediators (PG's, LT's and possibly PAF) and secondary cytokine generation. This sublethal model of LPS-induced shock represents a sensitive model for estimating the efficacy of potential drug candidates for the treatment of endotoxic shock.