[Osteotropic effect of ksidifon administered subcutaneously to rats during immobilization]

The role of ksidifon in the prevention of immobilization-induced osteoporosis was investigated. Osteoporosis was produced by placing animals (Wistar male rats weighing 200-230 g) into small-size cages for 60 days. Every day the rats were injected subcutaneously with ksidifon (hydroxyethylidene bisphosphonic acid) at a dose of 1 or 5 mg/kg. It was found histomorphometrically that ksidifon in these doses inhibited losses of cancellous bone from tubular bones, trunk and pelvic bones. The ksidifon effect was closely correlated with the initial metabolic state of bones. The drug changed the balance of bone cells. The population of osteoblasts decreased greatly whereas that of osteoclasts either remained unchanged or increased slightly. It is concluded that ksidifon is an agent that can be used to prevent osteoporosis, provided that the physiological state of bone and the organism as a whole is taken into consideration.