The effect of bone matrix on young connective tissue cells in culture.

Human and rat decalcified bone matrix preparations were shown to be active in inducing cartilage formation by subcutaneous implantation in the rat. When young rat fibroblastic cells were grown in cultures, which also contained bone matrix preprations in particulate form, the fibroblastic cells underwent a uniform and consistent morphological alteration. These altered cells showed higher rates of synthesis of hyaluronic acid and chondroitin sulfate than the controls and exhibited very active amino-sugar-nucleotide metabolism. It is suggested that this approach to the culture of connective tissue cells will allow a more precise definition of the early steps of connective tissue differentiation.