Differences in glycosaminoglycans derived from chick embryo chondrocytes grown in vitro and in vivo

Vertebral chondrocytes from 10-day-old chick embryos were examined after growth for five days in vitro and in vivo. The chondrocytes, including the hyaline matrix, from both methods of growth were extracted for glycosaminoglycuronoglycans and the partially purified polymers were analyzed for hexosamines. It was found that the chondrocytes, when removed from their cartilage matrix and grown in vitro, synthesized sulfated glycosaminoglycans which migrated in electrophoresis as chondroitin sulfates. The partially purified glycosaminoglycans were not, however, chondroitin sulfates since glucosamine was characterized as the major hexosamine. Neither galactose nor glucuronic acid were demonstrated as part of the glucosamine-containing polymer. The polymer was produced by the cells grown in vitro regardless of age or original location, dorsal or ventral, in the vertebral column. In contrast, chondrocytes which were grown in vivo for 10 or 15 days synthesized predominately a polymer which had characteristics of chondroitin 4- or 6-sulfate.