Calcitonin Stimualtes Bone Formation When Administered Prior to Initiation of Osteogenesis

The influence of calcitonin (CT) on various stages of bone formation was investigated. A demineralized collagenous bone matrix-induced bone forming system in rats was used to temporally segregate chondrogenesis and osteogenesis. Administration of CT at the initiation of matrix-induced bone formation (BF) resulted in a 76% stimulation of BF. This increase was due, in part, to a stimulation of cartilage and bone precursor cell proliferation. The results indicate CT has two actions: (a) when CT is administered during the initial phases of the bone formation, it increases BF due to a stimulation of proliferation of cartilage and bone precursor cells; and (b) when CT is administered after bone formation has been initiated, subsequent bone formation is suppressed.