[Growth factors and bone tissue. Implications in the formation of bone matrix]

Bone formation is highly dependent on the number of osteoblastic cells. Simulating factors which recruit osteoblastic cells play an essential role in regulating bone formation. Several growth factors produced locally by bone marrow cells and osteoblasts regulate cell growth and differentiation of osteoblastic cells. These growth factors may be systemic or local and can be stocked in the matrix. The factors secreted locally play a dominant role in regulation and are stocked in an active form in the bone matrix. Growth factors act through both autocrine and paracrine effects, or as local mediators of hormones and compression forces. The wide range of effects of the local growth factors and cytokines on bone cells, and the numerous interactions between these factors lead to precise regulation of the osteoblastic function. Thus these factors plan an extremely important role in local regulation and cell growth and osteoblastic differentiation, and are highly implicated in local control of bone formation.