Immunolocalization of S100A2 calcium-binding protein in cartilage and bone cells.

S100A2 protein, a Ca2+ binding protein, was investigated by immunocytochemistry in the epiphyseal cartilage and bone cells of growing rats, and in primary cultures of osteoblasts. S100A2 was detected in the chondrocytes and in the extracellular cartilage matrix. In the later however, its presence only in the calcifying areas of the epiphyseal cartilage suggests that it could be involved in the process of calcification of cartilage.