Morphological and histochemical studies in human rib cartilage chondrons of different age groups.

4- to 6-micrometer thick cryostat sections from rib cartilage of human corpses aged 1 day to 92 years were stained with basic dyes, digested with testes hyaluronidase and examined in polarized light. The areas of 50 chondrons in the cartilage periphery and of 50 chondrons in the cartilage center were measured. The anisotropic zones of the chondrons show a decreased size in the cartilage center as compared to those of the periphery. The basophilic zones of the chondrons (territories) were measured only in the cartilage center. The size of their areas is similar to that of the anisotropic areas. The zones of the chondrons with high chondroitin sulfate content as revealed by hyaluronidase (inner territorial zones) are smaller in the cartilage center than in the periphery and decrease with advancing age.