[Effect of diphosphonates on the development of osteoporosis in the hypokinetic rat].

Using histomorphometric methods, the effect of diphosphonates (hydroxydimethylaminopropylene diphosphonic acid and hydroxyethylene diphosphonic acid) on the development of osteoporosis in spongy matter of tibia and vertebrae of the rats exposed to hypokinesia for 60 days was investigated. It was found that aminopropylene diphosphonic acid in the dose 6 mg phosphorus/kg/day prevented osteoporosis and caused an increase in the volume density and abnormal (cartilage rich and poorly ossified) spongy bone. By contrast, ethylene diphosphonic acid in the dose 9 mg phosphorus/kg/day did not prevent osteoporosis but reduced its severity.