The use of avian epiphyseal chondrocytes for in vitro studies of skeletal metabolism.

Chondrocytes from the postembryonic avian epiphyseal growth plate are easily obtained and can be successfully cultured for a considerable length of time. Under the proper culture conditions, the chondrocytes will become confluent and achieve a hypertrophic morphology followed by mineralization of the extracellular matrix. Although this can be accomplished with a serum-free medium, the process is accelerated in the presence of serum. Minimal growth factor requirements for the serum-free medium include fibroblast growth factor and insulin-like growth factor. Transforming growth factor-beta and parathyroid hormone are also mitogenic for chondrocytes. Chondrocytes may have more critical requirements for amino acids because further supplementation of a conventional medium such as Dulbecco's modified Eagle's medium results in improved performance of the cultured cells. Ascorbic acid in the medium is very important for matrix vesicle production and mineralization of cartilage nodules.