Ibuprofen inhibits localized bone resorption in the middle ear

Abstract

Localized osteoclastic bone resorption plays a significant role in the pathogenesis of several diseases of the middle ear as well as orthodontic tooth movement and long bone remodeling. The mechanisms of control of localized bone loss and systemic bone resorption may be different but both may be mediated by a final common pathway which includes prostaglandins. Prostaglandins seem to have a predominantly stimulatory effect on bone resorption, although the exact mechanism is poorly understood. Ibuprofen, a nonsteroidal antiinflammatory drug, is known to inhibit the synthesis of prostaglandins. It is likely that ibuprofen, through its inhibition of prostaglandin synthesis, would decrease the localized osteoclastic bone resorption in a previously described animal model system. Mongolian gerbils were divided into three groups: low dose ibuprofen (10 mg/kg per day), high dose ibuprofen (30 mg/kg per day), and a control group. Following surgical implantation of catheters to the right bullae of each gerbil, pressure was applied for 8 days, stimulating osteoclastic bone resorption. After killing the animals and histomorphometric analysis of the bullae from each, comparisons were made between each group using osteoclast surface (percentage of bone area covered by osteoclasts), osteoclast number (number of osteoclasts/mm bone length), and osteoclast profile area (in microns2). Significantly lower osteoclast surface (Oc.S/BS) was found in pressurized bullae from both treatment groups when compared with pressurized bullae from controls (P less than 0.05) and significantly lower osteoclast number (N.Oc/T.L) in pressurized bullae from both treatment groups when compared with pressurized bullae from controls (P less than 0.05). These differences were found to be dose-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)