Alteration of cartilage specific proteoglycan with non-weight bearing articular cartilage.

The cartilage composed of chondrocytes and their surrounding extracellular matrix, and mechanical motion of joint may influence on the metabolism of cartilage. In order to determine whether non-weight bearing status alter the metabolism of cartilage, we made histological and biochemical analysis with incorporation of 35S and the distribution of the molecular size of proteoglycans produced in the case of disused cartilage. Histologically, there were seen no disorder in cell arrangement, but poorer in cellularity and thinner in cartilage width as compared with normal one. Biochemical analysis, however demonstrate that incorporation of 35S in newly synthesized glycosaminoglycan (GAG) was lower and the molecular size also smaller than that of control suggesting that mechanical stress is an important environmental factor in maintaining the differential function of the cartilage.