ABSTRACT
Particularly striking were the in vitro studies in which sequential collagenase digestions were used to isolate bone cell populations enriched with fibroblasts and preosteoblasts, or in which mature osteoblasts were taken directly from fetal Sprague-Dawley rat calvaria10. Strontium ranelate (10-3 mol/l) increased DNA synthesis 3-4-fold in the fibroblast + preosteoblast population. In mature osteoblasts, collagen and noncollagen protein synthesis increased by 34%. Of particular interest was the effect on bone formation, determined in calvarial cultures using autoradiography and histomorphometry: strontium ranelate enhanced preosteoblast replication, producing a corresponding increase in bone formation ≤ 48 h later. Moreover, the activity appeared specific in that the related compounds, calcium ranelate and sodium ranelate, had no such effect at the same concentration. This study confirmed an earlier finding that strontium ranelate acted positively on bone formation11.
