The effects of pamidronate on mechanical properties, growth and structural changes in rat bones.

Although a number of properties of bisphosphonates have been recognized which influence the metabolic process in bones, particularly those concerning the remodelling processes, the influence of this new group of drugs on the mechanical properties of bones remains an open issue. In order to clarify this problem, the present study concentrated on the influence of a new generation bisphosphonate, i.e. pamidronate upon the mechanical properties, growth, and morphological changes in the femoral and tibial bones in rats. The experiments carried out concerned pamidronate administration to male Wistar rats in doses of 3 mg/kg of body mass subcutaneously, for the period of 3 or 6 weeks. The total changes in the osseous tissue after pamindronate administration indicate the drug to foster the development of osteopetrosis in rats, the prominent sings of the disease being mainly deformations of epiphysis, decreased bone growth, increased thickness of epiphysial cartilage and bone trabeculae, as well as lowered resistance to fractures and decreased susceptibility to deformations.