Effect of Dexamethasone on Chondrocyte Cultures.

摘要

During bond induction by demineralized bone the most robust bond formation is associated with calcified cartilage. In order to examine this important component of the bone induction cascade, we examined whether chondrocytes could mineralize their matrix in culture. Cultures were treated with dexamethasone to determine whether this drug would promote chondrogenesis and calcification in a manner comparable to that seen in osteoblasts. The data suggest that dexamethasone may play a role by mediating alkaline phosphatase specific activity and nodule formation. Dexamethasone may stimulate cell proliferation and differentiation and rapidly elevate enzyme activity to levels optimal for calcification. In non-dexamethasone-treated cultures, increased enzyme activity may occur later but at higher levels. However, calcification may not occur until alkaline phosphatase activity is decreased to optimal levels. These data suggest that dexamethasone may be useful for promoting endochondral bone repair. (kt)