Differential responses of human articular cartilage to retinol.

An in-vitro study has been made of the response of aged human articular cartilage to the catabolic agent retinol. Weight bearing cartilage from the femoral condyle degrades and releases proteoglycan with an associated reduction of sulphate incorporation. Similar cartilage from the femoral head responds to the retinol with an inhibition of sulphate incorporation but no degradation or loss of proteoglycan. Extraction of the proteoglycan from the femoral head samples failed to demonstrate any evidence of breakdown.