Biosynthesis of chondroitin sulphate in cartilage regenerated from perichondrium

In a rabbit's ear cartilage an experimental defect was lined with a perichondrial flap and in a rabbit's trachea a defect in two tracheal cartilages was reconstructed with a free autogenous graft of aural perichondrium. Outgrowth of new tissue, morphologically indistinguishable from cartilage was observed within 4 weeks. In cartilage defects not bridged by perichondrium, no regeneration of cartilage occurred. Inorganic 35SO4, administered in vivo, was incorporated into the newly formed tissue. The labelled product was isolated and identified as chondroitin sulphate. The results support the view that authentic cartilage may be regenerated from the perichondrium.