Influence of a diphosphonate on the cellular aspect of young bone tissue

Stimulated by the rather sparse information in the literature on cellular changes induced by EHDP, we carried out electron microscopic investigations on young bone tissue and on de novo bone formation. Cellular changes could be observed during continuous administration of EHDP. The osteoblasts demonstrated temporary storing of crystalloid structures in the mitochondria, and atypical osteocytes showed persistent changes indicative of hyperactivity. The osteoclasts exhibited varying ultrastructural features with respect to the number and appearance of nuclei, Golgi, RER, and lysosomes. These changes under the influence of EHDP could be an indication of altered activity of the osteoclast. The possible interference of EHDP with bone cell metabolism is discussed.