The effects of tensile load on the metabolism of cultured chondrocytes

The effect of cyclic tensile load on articular cartilage metabolism was inv estigated experimentally using 12 Japanese White rabbits. Chondrocytes obta ined from the knee joints were cultured on plates with flexible silicone ru bber bases. They were subjected to a cyclic (3 seconds on and 3 seconds off ) tensile load for 24 hours with a maximum increase in area of 17%. Proteog lycan synthesis, collagen synthesis, and tissue inhibitors of metalloprotei nases production by the chondrocytes under the load were quantified and com pared with those produced by the control cells in an unloaded condition. Th e cultured chondrocytes under the cyclic tensile load perpendicularly align ed to the direction of the tensile load. Collagen synthesis and tissue inhi bitors of metalloproteinases production increased significantly under the c yclic tensile load, although no significant change in proteoglycan synthesi s was observed, These results suggested that the cyclic tensile load on the chondrocytes contribute to the regulation of articular cartilage metabolis m in part.