1. Effects of bisphosphonates on joint damage and bone loss in rat adjuvant-induced arthritis.
- Author
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H. Harada, T. Nakayama, T. Nanaka, and T. Katsumata
- Subjects
LABORATORY rats ,ARTHRITIS ,HISTOPATHOLOGY ,BONES - Abstract
Objective and design: Examination of the effects of bisphosphonates on joint damage and generalized bone loss. Materials: Adjuvant-arthritis was induced by injection of Mycobacterium butyricum into the footpad of the right hind paw of Lewis rats (8 animals/group) on day 0. Treatment: Arthritic rats were treated with the vehicle (saline), etidronate or alendronate (subcutaneously, daily 5 times a week for 3 weeks from day 1 to day 21). Experiment-1: Etidronate (0.1, 0.5, 2.5, 12.5 mg/kg) or alendronate (0.02, 0.1, 0.5, 2.5 mg/kg), Experiment-2: Etidronate (2.5, 5, 10mg/ kg) or alendronate (0.001, 0.01, 0.1 mg/kg). Methods: In the adjuvant-injected side of the hind limbs, paw swelling was evaluated at 1-week intervals, and bone mineral density (BMD) in the proximal tibia, histopathology and radiographical findings in the tibio-tarsal region were evaluated at the time of sacrifice (on day 21). Results: In all treatment schedules, both bisphosphonates significantly prevented paw swelling and bone loss. Alendronate reduced paw swelling at higher doses (over 0.1 mg/ kg) compared with its effect on BMD decrease (over 0.001 mg/kg). In contrast, etidronate reduced paw swelling and joint damage at doses similar to those (over 2.5 mg/kg) prevented BMD decrease. Conclusions: Both etidronate and alendronate are effective in reducing arthritic damage, but their effective dose ranges for inflammatory responses and BMD decrease clearly differ; i.e., the etidronate dose ranges for anti-inflammatory and anti-resorptive effects are similar, whereas the dose range for anti-inflammatory effects of alendronate is 100-fold higher than that for its anti-resorptive effects. [ABSTRACT FROM AUTHOR]
- Published
- 2004