Chronic bone pain in osteoporosis is a commonly encountered clinical problem. Previously, we have shown that a closed femur fracture model in the rat can be used to model the enduring pain that follows bone fracture (Brot et al, SFN 2003). In order to further characterize the hyperalgesia observed in this model we have investigated commonly used pain medications for their effects on mechanical hyperalgesia and spinal GFAP staining . Male Sprague-Dawley rats received either a sham surgery or a right femur closed fracture with intramedullary pin (CF+PIN) or a pin insertion (PIN) only. Three weeks after surgery, the rats were tested for mechanical hyperalgesia using the von Frey technique. In addition, mechanical hyperalgesia was evaluated in 3 groups of animals that were administered escalating doses of calcitonin, gabapentin or ketorolac at 48 hours intervals. At the conclusion of the experimental period the lumbar spinal cord was harvested and stained for GFAP. Compared to intact and PIN control, mechanica...