The Effects of Diphosphonates, Polyphosphates, and Calcitonin on “Immobilisation Osteoporosis” in Rats

Abstract

Abstract. Dichloromethylenediphosphonate (Cl 2 MDP) and ethane‐l‐hydrory‐l,l‐diphosphonate (EHDP), two compounds related in structure to inorganic pyrophosphate but which contain P—C—P instead of P—O—P bonds, have been shown to inhibit the osteoporosis induced by the immobilisation of the hind limbs of rats. These effects may be due to the ability of diphosphonates to inhibit bone resorption. A polyphosphate and porcine calcitonin inhibited the osteoporosis only slightly. Diphosphonates may prove useful in the therapy of osteoporosis and other diseases in which bone resorption is increased.