Articular chondrocytes were enzymatically isolated from mature bovine
cartilage and separated by density zone-velocity sedimentation in a
gradient. For cells from different levels of the gradient, size and
staining characteristics were determined and rates of incorporation of
tritiated cytidine and radiosulphate were measured as indicators of RNA and
sulphated glycosaminoglycan synthesis, respectively. The data clearly show
that the chondrocyte population is composed of cells that vary continuously
in size and metabolic activity from one limit to another. The largest cells
also demonstrated the greatest RNA production while the smallest cells had
the least. There was, however, no such differentiation of sulphated
proteoglycan production.